refrigerator

Abstract

To provide a highly reliable refrigerator which inhibits foods stored in a storage room in a refrigeration temperature zone from being frozen.SOLUTION: A refrigerator includes: a cooler 4: a storage room 3 in a refrigeration temperature zone; an in-room fan 9 which forms airflow in the storage room 3; a door which may close a front opening of the storage room 3; a shelf 34b disposed within the storage room 3; a food placement surface; and a cooler room which is disposed including an area located substantially immediately below the placement surface and in which the cooler 4 is stored. The refrigerator includes temperature compensation means which increases a temperature of the placement surface. The temperature compensation means blows air to the storage room 3 (air blowing operation) in a state that the refrigerant is not supplied to the cooler 4.SELECTED DRAWING: Figure 12

Description

Technical Field

[0001] The present invention relates to a refrigerator.

Background Art

[0002] Patent Document 1 discloses a refrigerator in which a refrigerating chamber is arranged in the upper stage and a freezing chamber is arranged in the lower stage, a cooler is installed in a cooler storage chamber (cooler chamber) at the lower part of the refrigerating chamber, a compressor and a blower are driven, and the cold air of the cooler is blown to cool the refrigerating chamber.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the refrigerator described in Patent Document 1, a cooler chamber is arranged below the refrigerating chamber which is a storage chamber in the refrigerating temperature range, and the refrigerating chamber is cooled by driving a compressor and a blower to blow the cold air of the cooler. At this time, when food is stored in the storage part located above the cooler chamber, the food may be excessively cooled from the low-temperature cooler storage chamber and may even freeze.

Means for Solving the Problems

[0005] The refrigerator of the present invention includes a cooler, a storage chamber in the refrigerating temperature range, an in-cabinet blower for forming an air flow in the storage chamber, a door capable of closing the front opening of the storage chamber, a fixed shelf or a detachable shelf arranged in the storage chamber, a food placement surface, and a cooler chamber for storing the cooler, which is arranged including a region substantially directly below the placement surface. ,before temperature compensation means for raising the temperature of the described placement surface, and is provided with The temperature compensation means includes a directional means that, when no refrigerant is supplied to the cooler, blows air into the storage chamber, forming the storage chamber from above to the front of the cooler chamber, and provides a return opening at the front for returning the air from the storage chamber back to the cooler chamber, and directs the air so that it has a velocity component toward the upper surface side of the cooler chamber. .

Brief Description of the Drawings

[0006] [Figure 1] This is a front view of a refrigerator according to this embodiment. [Figure 2] This is a front view with the door in Figure 1 removed. [Figure 3] This is a cross-sectional view AA in Figure 1. [Figure 4] This is a cross-sectional view of BB in Figure 1. [Figure 5] This is a diagram showing the configuration of the refrigeration cycle of the refrigerator according to this embodiment. [Figure 6] Figure 3 is a cross-sectional view of CC. [Figure 7] This is a partially enlarged cross-sectional view of Figure 3. [Figure 8] This is a partially exploded perspective view showing the relationship between the cooler, return piping, and drainpipe of the refrigerator according to this embodiment. [Figure 9] This is a cross-sectional view of the heat exchange section. [Figure 10] This is a perspective view of the cooling unit. [Figure 11] This is a perspective view of the cooling unit with the lid attached to the case. [Figure 12] This is a time chart showing the control state of the refrigerator according to this embodiment. [Figure 13] This diagram illustrates the relationship between the position of the return pipe and the temperature in the refrigerator according to this embodiment. [Figure 14] This is a top view of the refrigerator according to this embodiment with the top plate removed. [Figure 15] This is a front view of the door sensor. [Figure 16] This diagram shows the wiring specifications for the door sensor according to this embodiment (for right-opening doors). [Figure 17] This diagram shows the wiring specifications for the door sensor according to this embodiment (for left-opening doors). [Figure 18] This is a rear view of the refrigerator according to this embodiment with the outer panel removed. [Modes for carrying out the invention]

[0007] Hereinafter, embodiments of the refrigerator according to the present invention will be described with reference to Figures 1 to 18. Figure 1 is a front view of the refrigerator according to the present embodiment. As shown in FIG. 1, the refrigerator 1 includes a heat-insulating box body 10, a door 2, and a plurality of legs 10a. Further, a suction port 27 and an exhaust port 28 are provided on the front side (front surface side) of the heat-insulating box body 10. Specifically described, the suction port 27 and the exhaust port 28 are provided side by side below the opening blocked by the door 2. The suction port 27 is an opening for guiding air to a machine room 25 (see FIGS. 3 and 6) described later. The exhaust port 28 is an opening for exhausting air from the machine room 25 (see FIG. 6).

[0008] Figure 2 is a front view of the state where the door of FIG. 1 is removed. As shown in FIG. 2, the refrigerator 1 includes a storage room 3 in the heat-insulating box body 10 for storing food in a refrigerated temperature zone. In the storage room 3, a shelf 33 is provided in the upper stage, shelves 34a (front) and 34b (rear) are provided in the middle stage, and a container 35 is provided in the lower stage. In the present embodiment, the upper surfaces of the shelves 34a and 34b are the placement surfaces 34c of the food. Note that the shelves 34a and 34b may be fixed shelves or detachable shelves.

[0009] For example, an in-cabinet lamp 99 is arranged on the top surface of the storage room 3. The in-cabinet lamp 99 emits warm-color light such as orange, and has a light axis, for example, directly below or slightly behind this, and for example, an LED lamp can be used. Further, the wall surface in the storage room 3 is painted in a dark color system such as black, for example. Thereby, the refrigerator 1 has a light source that does not give a sense of incongruity even when installed in a calm space such as a bedroom, and can also calm the light reflection and the like. The element serving as the light source of the in-cabinet lamp 99 can be, for example, only one in order to give a calm impression, but may be about two or three.

[0010] Further, the heat-insulating box body 10 includes a cooler chamber 8 in which a cooler 4 is housed at the rear of the lower stage of the storage chamber 3. This cooler chamber 8 is arranged in the heat-insulating box body 10 including a region substantially directly below the placement surface 34c. Further, the storage chamber 3 is formed from above the cooler chamber 8 to the front. Further, the storage chamber 3 is located vertically above the cooler 4 and also in front of (in front of) the cooler 4. Further, the storage chamber 3 and the cooler chamber 8 are partitioned by a storage chamber surface member 74 (see FIG. 7).

[0011] In front of the cooler chamber 8, a return opening 22 that opens downward is provided. Further, an indoor fan 9 is provided on the back of the cooler chamber 8. Note that a backward fan (turbo fan), which is a centrifugal fan, is used for the indoor fan 9. An air duct 20 is provided above the indoor fan 9. The air duct 20 includes discharge ports 21a, 21b that open forward and discharge ports 21c, 21d that open laterally. The air that has exchanged heat with the cooler 4 is pressurized by the indoor fan 9 and sent from the discharge ports 21a, 21b, 21c, 21d of the air duct 20 to the storage chamber 3 to cool the inside of the storage chamber 3. On the back of the storage chamber 3, a storage chamber temperature sensor 45 (temperature estimation means) that detects the temperature of the region formed between the shelves 33 and 34a, 34b is provided. This storage chamber temperature sensor 45 is provided in the storage chamber 3 formed above the placement surface 34c. Further, on the back of the storage chamber 3, an operation unit (not shown) capable of setting the temperature is provided.

[0012] FIG. 3 is a cross-sectional view taken along the line A-A of FIG. 1. FIG. 4 is a cross-sectional view taken along the line B-B of FIG. 1. As shown in Figures 3 and 4, the refrigerator 1 is equipped with steel plate outer panels 11 on the left and right sides, the back, and the bottom of the insulated box 10, which are the outer surfaces of the box. It is also equipped with a removable top plate 12 on the top surface. The top plate 12 is a thin sheet of synthetic resin provided on the top surface of the insulated box 10, and is treated with a predetermined surface finish to make it easy to clean and to enhance its design. Inside the top plate 12 (inside the box), there is a ceiling plate 13 made of synthetic resin. The top plate 12 is fixed with screws (not shown). Inside the top plate 12, there is also a door sensor 96 (see Figure 14), a relay wire 94 (see Figure 14), an external temperature sensor (not shown), and an external humidity sensor (not shown).

[0013] Furthermore, the refrigerator 1 is equipped with an inner box 18 made of synthetic resin on the inside of the insulated box body 10. Insulation material 5 (for example, expanded polystyrene or expanded urethane) that has been pre-molded or processed to predetermined dimensions is provided between the outer panel 11 and the inner box 18, and between the ceiling panel 13 and the inner box 18. In other words, the refrigerator 1 does not employ a method of foaming and filling the space between the outer panel 11 or ceiling panel 13 and the inner box 18 with urethane. As a result, the foaming equipment required when foaming and filling with urethane is unnecessary, making it possible to manufacture a refrigerator with a high degree of freedom that is not limited by foaming equipment and is at a lower cost. The insulation material 5 is divided into multiple pieces, and the insulation material 5 is joined to each other with aluminum tape (details will be described later with reference to Figure 18). Dividing the insulation material 5 into multiple pieces in this way improves the ease of assembly.

[0014] Furthermore, the refrigerator 1 is equipped with a front edge steel plate 17 on the front edge of the insulated box body 10. Condensation suppression piping 52, which will be described later, is installed on the inner surface of the front edge steel plate 17. As a result, heat is effectively spread to the front edge of the insulated box body 10 by the action of the front edge steel plate 17, which is made of a metal with high thermal conductivity, and condensation is suppressed.

[0015] Door 2 is equipped with a removable front panel 14 on its front surface. The front panel 14 can be made of synthetic resin, glass, iron, or other materials. The back of door 2 is equipped with an inner door member 15 made of synthetic resin. Between the front panel 14 and the inner door member 15, there is a first door insulation material 7 (expanded polystyrene) that has been pre-molded to a predetermined size, and a second door insulation material 6 (foamed urethane) that has been processed into a roughly rectangular parallelepiped shape with higher insulation performance than the first door insulation material 7. The top surface of door 2 is equipped with an upper surface member 16a made of synthetic resin, and the bottom surface is equipped with a lower surface member 16b made of synthetic resin. A sealing member 19 is provided on the outer periphery of the inner side of door 2 at a position facing the front edge steel plate 17 of the insulated box body 10. The door 2 and the insulated box body 10 are kept closed by the attractive force of a magnet (not shown) provided inside this sealing member 19. Furthermore, the inner surface member 15 of the door is provided with multiple vents 15a, allowing air to circulate in the minute gaps formed between the second door insulation material 6 and the inner surface member 15. As a result, the air inside the storage room 3, which becomes low in humidity due to the dehumidifying action of the cooler 4, acts on the minute gaps formed between the second door insulation material 6 and the inner surface member 15 through the vents 15a, making it difficult for condensation to occur due to water vapor in the air present between the front panel 14 and the inner surface member 15. In addition, the vents 15a open downwards, preventing water droplets from flowing down and entering the inside of the inner surface member 15, and preventing dust from falling in and entering.

[0016] Furthermore, the refrigerator 1 is equipped with a cooler compartment 8 in the lower rear of the storage compartment 3, where a cooler 4 is housed. The cooler compartment 8 has a return opening 22 that opens downwards on the front side. The cooler compartment 8 is also equipped with an internal fan 9 at its rear. The internal fan 9 is a centrifugal fan, specifically a rearward-facing fan (turbo fan). Above the internal fan 9 is an air supply duct 20 equipped with multiple discharge ports 21a to 21d. By using a centrifugal fan for the internal fan 9 in this way, the air drawn in from the cooler compartment 8 at the front can be smoothly redirected towards the air supply duct 20 above, enabling a compact implementation. Below the internal fan 9 is a gutter 30. At the lowest point of the inclined surface of this gutter 30 is a drain port 31 for draining condensation water and melted frost water generated around the internal fan 9.

[0017] Furthermore, the refrigerator 1 has a machine room 25 located at the bottom (outside the interior) of the insulated box 10. As shown in Figure 3, the machine room 25 contains a compressor 24 and a radiator 50 installed in a radiator air passage 160 at the front bottom. A suction port 27 is provided at the inlet of the radiator air passage 160 in front of the radiator 50, and a filter 27a is provided at the suction port 27. By installing the filter 27a in this way, dust is prevented from accumulating on the fin surface of the radiator 50, which is a fin-tube type heat exchanger, and from narrowing or blocking the airflow between the fins. Also, as shown in Figure 4, the machine room 25 contains an external blower 29 and an evaporation tray 42. The external blower 29 is covered by a casing 44 that opens downwards, and the air blown from the external blower 29 flows over the top surface of the evaporation tray 42. The evaporator tray 42 is equipped with an exhaust port 28 at its front. Driven by an external blower 29, air is drawn in from the intake port 27 (see Figure 3), and the air, whose temperature has risen due to heat exchange by cooling the radiators 50 and compressor 24, flows over the top surface of the evaporator tray 42 and is exhausted from the exhaust port 28. The rear of the machine room 25 is covered with a removable cover 92 that does not have intake or exhaust ports. The bottom surface of the machine room 25 is formed by a steel plate base member 43.

[0018] Furthermore, the refrigerator 1 is equipped with a heat exchange section 57 (heating section) at the bottom of the cooler 4 in the cooler compartment 8, which is formed by joining a return pipe 58 and a capillary tube 53, as described later. The cooler compartment 8 is also equipped with a gutter 30 on its lower surface, and as shown in Figure 3, a drain port 31 is provided at the lower end (lowest position) of the gutter 30. A drain pipe 32 is connected to the drain port 31, and as shown in Figure 4, the drain pipe 32 is connected to the upper part of the evaporation tray 42 (communicating with the machine room 25 where the compressor 24 is installed). The drain port 31 is located downstream of the air inlet surface 4a of the cooler 4 (see Figure 3) and upstream (suction side) of the internal fan 9.

[0019] Figure 5 is a diagram showing the configuration of the refrigeration cycle of the refrigerator according to this embodiment. As shown in Figure 5, the refrigeration cycle 150 of the refrigerator 1 in this embodiment includes a compressor 24, a radiator 50 (heating pipe), which is a fin-tube type heat exchanger that dissipates heat from the refrigerant connected to the compressor 24 via a discharge pipe 59, and a wall heat dissipation pipe 51 (heating pipe), which is connected to the radiator 50 via a connecting pipe 151 (heating pipe) and is arranged to substantially contact the inner surface of the outer plate 11 that forms the outer surface of the left and right sides, back, and bottom of the insulated box body 10. Furthermore, the refrigeration cycle 150 includes a condensation suppression pipe 52 (heating pipe), which is a heat dissipation pipe that heats the front edge steel plate 17 to suppress condensation, and is connected to the wall heat dissipation pipe 51 and the connecting pipe 151 (heating pipe), and is positioned to be in substantially contact with the inner surface of the front edge steel plate 17 of the insulated box body 10; a dryer 55 that removes moisture from the refrigerant and is connected to the condensation suppression pipe 52 and the connecting pipe 151; a capillary tube 53 (heating pipe), which is a pressure reducing means that reduces the pressure of the refrigerant and is connected to the dryer 55; and a cooler 4 that absorbs heat from inside the chamber by exchanging heat between the refrigerant and the air inside the chamber.

[0020] Furthermore, the refrigeration cycle 150 is equipped with a gas-liquid separator 54 in the piping on the outlet side of the heat transfer tubes 41 that form the cooler 4, and the outlet side of the gas-liquid separator 54 is connected to a return pipe 58 (outlet pipe). The return pipe 58 is connected to the compressor 24. In addition, the refrigeration cycle 150 has a heat exchange section 57 in which a portion of the return pipe 58 exchanges heat with a capillary tube 53. The inner diameter of the wall heat dissipation pipe 51 and the condensation suppression pipe 52 is, for example, 3.2 mm, and the inner diameter of the capillary tube 53 is, for example, 0.85 mm, which is less than one-third of the inner diameter of the wall heat dissipation pipe 51 and the condensation suppression pipe 52.

[0021] Next, the flow of refrigerant in the refrigeration cycle 150 of the refrigerator 1 of this embodiment will be described. In the refrigerator 1 of this embodiment, when the compressor 24 is driven, the refrigerant is compressed into a high-temperature, high-pressure gaseous refrigerant and enters the radiator 50 via the discharge pipe 59. In the radiator 50, heat is removed from the refrigerant by ventilation from the external blower 29 (see Figure 4), reducing its enthalpy and creating a two-phase state, which then flows into the wall heat dissipation pipe 51 via the connecting pipe 151. In the wall heat dissipation pipes 51, which are located on both sides, the bottom, and the back of the insulated box 10, the enthalpy is further reduced by heat exchange mainly with the outside air via the outer plate 11 of the insulated box 10. Subsequently, the refrigerant enters the condensation suppression pipe 52 located on the front edge steel plate 17 via the connecting pipe 151. In the condensation suppression pipe 52, heat exchange occurs via the front edge steel plate 17, turning it into a liquid refrigerant, which then reaches the dryer 55 via the connecting pipe 151, where moisture is removed before entering the capillary tube 53.

[0022] In the capillary tube 53, the high-temperature, high-pressure refrigerant is reduced in pressure to become a low-temperature, low-pressure two-phase refrigerant, which then reaches the inlet of the cooler 4. The refrigerant flows through the heat transfer tubes 41 of the cooler 4, exchanging heat with the air inside the cooler. As the enthalpy increases and the degree of dryness rises, it becomes a nearly saturated gaseous refrigerant and reaches the outlet of the cooler 4. From the outlet of the cooler 4, the return pipe 58 that returns to the compressor 24 is heated by the refrigerant in the capillary tube in the heat exchange section 57, causing its temperature to rise (enthalpy to rise) before returning to the compressor 24. The refrigerant sealed in the refrigeration cycle 150 is isobutane, a flammable refrigerant.

[0023] Furthermore, the discharge pipe 59, radiator 50, wall heat dissipation pipe 51, condensation suppression pipe 52, and connecting pipe 151 are high-temperature, high-pressure refrigerant pipes, and the capillary tube 53 is a pressure-reducing pipe that reduces the temperature of the high-temperature, high-pressure refrigerant to a low temperature and low pressure. In all cases, the refrigerant flowing through them is at a temperature higher than the refrigerant temperature at the inlet of the return pipe 58, so these are heating pipes that have the capacity to heat the return pipe 58.

[0024] Figure 6 is a cross-sectional view of CC in Figure 3. Figure 6 is a rear view of the machine room 25 and the area above it. As shown in Figure 6, the refrigerator 1 is equipped with a compressor 24 in the machine room 25, and an external blower 29 and a circuit board storage box 70 are located to the right of the compressor 24 in a front view (left in a rear view). The external blower 29 is mounted in a casing 44, which has an opening at the bottom and is designed to discharge air toward the evaporation tray 42. By opening the casing 44 toward the evaporation tray 42 in this way, air can be blown onto the water accumulating in the evaporation tray 42, thereby promoting evaporation. The top of the evaporation tray 42 is equipped with a cover body 42a with openings for connection to the casing 44 and connection to the drain pipe 32, and the casing 44 and drain pipe 32 are connected to these openings. This prevents a short circuit in which air discharged from the external blower 29 leaks out from the space between the evaporation tray 42 and the cover body 42a and is drawn back into the external blower 29. Furthermore, the circuit board housing box 70 includes a circuit board 71 having a power system circuit board on which an inverter device and the like are mounted, and a control system circuit board on which a control circuit is mounted.

[0025] Furthermore, the refrigerator 1 is located on the left side when viewed from the front (right side when viewed from the rear) of the compressor 24 in the machine room 25. The inlet 59a of the discharge pipe 59 is connected to the discharge port 24a of the compressor 24, and the outlet 58b of the return pipe 58 is connected to the return port 24b of the compressor 24. The discharge pipe 59 is connected to the heat sink 50 (see Figure 5), and the return pipe 58 is connected to the cooler 4 (see Figure 5).

[0026] On the left side of the compressor 24 in a front view (right side in a rear view), there is a connecting pipe 151 at the outlet (downstream) side of the condensation suppression pipe 52, and a dryer 55 is connected to the connecting pipe 151. A capillary tube 53, shown by a dashed line, is connected to the outlet (downstream) side of the dryer 55. The capillary tube 53 is joined (thermally in contact) with the return pipe 58 by solder, and constitutes a heat exchange section 57. In other words, the capillary tube 53 functions as a heating section that heats the return pipe 58 to raise the temperature of the refrigerant.

[0027] Furthermore, the return pipe 58 and the capillary tube 53 are inserted between the outside (machine room 25) and the inside (cooler room 8) of the insulated box 10 through a communication hole 80 (gap) formed in the insulated box 10, and are led to the outside of the insulated box 10. A sealing member such as soft urethane (not shown) is installed in this communication hole 80 to fill the gap between the return pipe 58 and the capillary tube 53 and the communication hole 80. Although the gap formed in the communication hole 80 is filled using the sealing member, it is difficult to completely fill the gap, and air remains in the communication hole 80.

[0028] Furthermore, the heat exchange section 57, which is the contact point between the capillary tube 53 and the return pipe 58, is located throughout the entire space within the communication hole 80. In addition, the heat exchange section 57, which is the contact point between the capillary tube 53 and the return pipe 58, is also provided in the portion of the return pipe 58 upstream of the communication hole 80. In other words, the return pipe 58 is configured to maintain contact with the capillary tube 53 after leaving the cooler 4 until it passes through the communication hole 80.

[0029] Furthermore, a gas-liquid separator storage space 66 is provided on the interior side of the communication hole 80. The gas-liquid separator 54, which is attached to the piping on the outlet side of the cooler 4, is installed in the gas-liquid separator storage space 66 almost vertically so that the refrigerant flows from bottom to top. An electric heater 60 is also installed at the bottom of the gas-liquid separator storage space 66 as a heating means. Frost may grow on the gas-liquid separator 54, which separates the low-temperature liquid refrigerant from the cooler 4, and on the surrounding piping and structures, so the heating means (electric heater 60) is provided to ensure that the frost is melted. A drain port 62 is provided at the bottom end (lowest position) of the gas-liquid separator storage space 66, and if melted water is generated, it is drained through the drain port 62 into the gutter 30 at the bottom of the cooler room 8.

[0030] Furthermore, the refrigerator 1 has an outlet opening 160a of the radiator air passage 160 (see Figure 3) located at the front left side (right side when viewed from the rear) of the machine room 25, positioned in front of the compressor 24. This allows the compressor 24 to be cooled effectively by the air flowing through the radiator 50 (see Figure 3), making it less likely for the compressor 24 to malfunction due to excessive overheating.

[0031] Figure 7 is a partially enlarged cross-sectional view of Figure 3. The detailed structure around the cooling compartment 8 of the refrigerator 1 according to this embodiment will be explained using Figure 7. As shown in Figure 7, the refrigerator 1 is equipped with an insulating material 75 (expanded polystyrene) and a storage compartment surface member 74 (made of synthetic resin) at the top of the cooler compartment 8, and a flow path 76 is formed between the shelf 34b and the storage compartment surface member 74. The gap dimension L1 (flow path dimension) between the rear end 34b1 of the shelf 34b at the rear of the middle section of the storage compartment 3 and the front surface 74a of the storage compartment surface member 74 facing forward is 3 mm. The gap dimension L2 (flow path dimension) between the front end 34a1 of the shelf 34a at the front of the middle section and the inner surface member 15 of the door 2 is 20 mm. The gap dimension L3 (flow path dimension) between the bottom surface 34b2 of the shelf 34b at the rear of the middle section of the storage compartment 3 and the storage compartment surface member 74 located at the top of the cooler compartment 8 is 5 mm. The front opening dimension (vertical opening dimension) L4 of the return opening 22, which is formed between the lower end 74b of the storage compartment surface member 74 that forms the front surface of the return opening 22 and the surface of the inner box 18, is 30 mm. The front opening dimension L4 is the front opening dimension (vertical opening dimension) of the return opening 22. The depth opening dimension (horizontal opening dimension) L5 of the return opening 22, which is formed between the rear edge of the lower end 74b of the storage chamber surface member 74 and the front surface of the gutter forming member 100, is 20 mm. The depth opening dimension L5 is the depth opening dimension (horizontal opening dimension). The height dimension L6 of the cooler 4 is 50 mm. A bypass channel 77 is formed between the upper edge (upper end of the fins) of the cooler 4 and the lower surface 75a of the insulation material 75, and the dimension L7 of the bypass channel is 2 mm. The thickness L8 of the insulation material 75 is 10 mm. The horizontal gap dimension L9 between the front edge 4s (front edge of the front row fins) of the cooler 4 and the gutter forming member 100 is 3 mm. Furthermore, by ensuring the gap dimension L9 in this way, the molten water generated when frost growing on the fins of the cooler 4 melts can be prevented from flowing into the storage chamber 3 and instead directed to the gutter 30, thereby increasing reliability. In addition, by setting the gap dimension L9 to 1 mm or more, for example 3 mm, as in the refrigerator 1 of this embodiment, the molten water can be directed to the gutter 30 more reliably.

[0032] Furthermore, gap dimension L1 is the gap of the flow path R1 (see Figure 7) formed behind the mounting surface 34c, and gap dimension L2 is the gap of the flow path R2 (see Figure 7) formed in front of the mounting surface 34c. Also, gap dimension L1 is configured to be smaller than gap dimension L2 (gap dimension L1 < gap dimension L2).

[0033] Furthermore, the gap dimension L3 is the gap of the flow channel 76 formed on the lower (bottom) side of the mounting surface 34c. Also, the gap dimension L3 is configured to be larger than the gap dimension L1 (gap dimension L1 < gap dimension L3).

[0034] The forward opening dimension (vertical opening dimension) L4 of the return opening 22 is configured to be larger than the depth opening dimension (horizontal opening dimension) L5 (L4 > L5). This relationship allows it to function as a directional means that directs the airflow to have a velocity component toward the upper surface of the cooler chamber 8. Furthermore, the bottom of the cooler 4 is open and there is no wall separating it from the gutter 30. Generally, when a heat exchanger is installed in a flow path, a wall is provided around it to ensure that air passes through the heat exchanger. However, if a wall is provided between the cooler 4 and the gutter 30, the drainage of molten water generated when the frost on the cooler 4 melts will be hindered. Therefore, by leaving the bottom of the cooler 4 open as in the refrigerator 1 of this embodiment, the molten water can be easily drained into the gutter 30. Moreover, by providing a directional means that has a velocity component toward the upper surface of the cooler chamber 8, even without a wall below the cooler 4, it becomes difficult for airflow to leak below the cooler 4, thus achieving both high heat exchange efficiency and good drainage.

[0035] Furthermore, the drain port 31 formed in the gutter 30 is located downstream of the air inlet surface 4a of the cooler 4 (see Figure 3) and upstream of the internal fan 9. The drain port 31 is also connected to the downstream side of the external blower 29.

[0036] Furthermore, the drain pipe 32 connected to the drain outlet 31 of the gutter 30 penetrates the insulated box 10. That is, the drain pipe 32 penetrates through the through hole 18v formed in the inner box 18, the through hole 5v formed in the insulation material 5, and the through hole 11v formed in the outer plate 11, and extends to the evaporation tray 42 (see Figure 6) inside the machine room 25.

[0037] Figure 8 is an exploded perspective view showing the relationship between the cooler, return piping, and drain of the refrigerator in this embodiment. Figure 9 is a cross-sectional view of the heat exchange section. As shown in Figure 8, the cooler 4 is a fin-tube type heat exchanger consisting of multiple fins 40 and heat transfer tubes 41. The heat transfer tubes 41 of the cooler 4 are equipped with a cooler temperature sensor 46 that detects the temperature of the cooler 4. In addition, a heat exchange section 57 is located at the bottom of the cooler 4, where a capillary tube 53 and a return pipe 58 are in thermal contact. As shown in Figure 9, the heat exchange section 57, which is the contact part between the return pipe 58 and the capillary tube 53, is covered on its surface with an insulating material 90 (ethylene propylene rubber foam as an example). Note that the insulating material 90 is not shown in Figure 8. The heat transfer tube inlet 41a of the cooler 4 is connected to the outlet 53a of the capillary tube 53. The heat transfer tube outlet 41b of the cooler 4 is connected to the inlet 58a of the return pipe 58.

[0038] A trough 30 is positioned in the downward projection area of ​​the heat exchange section 57. The return pipe 58 is installed in the upward projection area of ​​the trough 30 (see Figure 8). The heat exchange section 57 (heating section) is installed in multiple rows (two rows, front and back, in this embodiment of the refrigerator 1) between the cooler 4 and the trough 30. At this time, the row downstream of the return pipe 58 (front side in the front-to-back direction), where the temperature is higher, is positioned close to the fins on the air inlet side (front) of the cooler 4 (upstream side of the cooler's airflow) (see Figure 7). The trough 30 is formed by a trough forming member 100 made of synthetic resin. The trough forming member 100 has a first support part 101 that supports the cooler 4, a second support part 102 that supports the heat exchange section 57, and an intake port 26 for the internal fan 9.

[0039] Figure 10 is a perspective view of the cooling unit included in the refrigerator according to this embodiment. As shown in Figure 10, the refrigerator 1 is equipped with a cooling unit 250. The cooling unit 250 is a unitized assembly of components such as the cooler 4 and the internal fan 9, and is located inside the inner box 18 (see Figure 3). The cooling unit 250 also includes the cooler 4, the internal fan 9, a gas-liquid separator 54 (also called a header or accumulator), an electric heater 60, a return pipe 58, a capillary tube 53, and a housing 67.

[0040] The cooler 4 is a heat exchanger through which a low-temperature, low-pressure refrigerant, reduced in pressure by a capillary tube 53, flows. The cooler 4 also comprises a number of fins 40 arranged with predetermined gaps between them, and heat transfer tubes 41 that penetrate these fins 40. A gutter 30 (see Figure 3) for receiving condensation water is provided on the underside of the cooler 4.

[0041] The internal fan 9 is a blower that pressurizes and pumps the air cooled by the cooler 4 towards the storage chamber 3 (see Figure 3), and is located on the rear side of the cooler 4. The intake side (front side) of the internal fan 9 faces the space 68 where the cooler 4 is located (the space on the intake side of the internal blower). The air cooled by the cooler 4 is then drawn backward towards the internal fan 9 and then blown out into the storage chamber 3 (see Figure 3) via a predetermined air passage (see Figure 3).

[0042] The gas-liquid separator 54 is a shell-shaped container connected to the downstream side of the cooler 4. This gas-liquid separator 54 has the function of separating the refrigerant flowing in from the cooler 4 into gas and liquid, and storing excess liquid refrigerant. The electric heater 60 is a heat source for warming the gas-liquid separator 54 and is installed below the gas-liquid separator 54. Since the gas-liquid separator 54 cools down easily with low-temperature liquid refrigerant, the electric heater 60 is installed to melt frost that forms on the gas-liquid separator 54 and its surroundings. Since the liquid refrigerant is stored at the bottom of the gas-liquid separator 54, the electric heater 60 may be installed on the outer surface of the gas-liquid separator 54 to directly heat the gas-liquid separator 54, or it may be installed only on the lower part of the outer surface of the gas-liquid separator 54 to heat it efficiently.

[0043] The return pipe 58 is a pipe that guides the gaseous refrigerant separated into gas and liquid form by the gas-liquid separator 54 to the compressor 24 (see Figure 3). The upstream end of the return pipe 58 is connected to the gas-liquid separator 54, and the downstream end is connected to the suction side of the compressor 24 (see Figure 3). As shown in Figure 10, the area near the downstream end of the return pipe 58 extends vertically below the housing 67.

[0044] The capillary tube 53 is a thin tube used to reduce the pressure of the refrigerant that has passed through the compressor 24 (see Figure 2), radiator 50, wall heat dissipation piping 51, condensation suppression piping 52, etc. in sequence. The downstream end of the capillary tube 53 is connected to the cooler 4. As shown in Figure 10, the area near the downstream end of the capillary tube 53 extends vertically below the housing 67 and is adjacent to the return piping 58.

[0045] The housing 67 is a resin component that houses the cooler 4, the internal fan 9, and the like. The housing 67 comprises a box-shaped case 67a with an open top and a lid 67b (see Figure 11) that closes the top opening of the case 67a. The cooler 4 is installed horizontally inside the case 67a. The case 67a also includes a partition plate 671a that separates the cooler 4 from the internal fan 9. An intake port 26, consisting of a circular hole, is provided in the partition plate 671a at the location corresponding to the intake side of the internal fan 9. The front plate 671c of the case 67a is provided with an opening 671d for guiding air from the storage chamber 3 (see Figure 3) to the cooler 4. Ribs 671e are provided around the opening 671d so as to protrude forward.

[0046] Figure 11 is a perspective view of the cooling unit with the lid installed on the case. As described above, the lid 67b closes the upper opening of the case 67a and has an L-shape when viewed from the side. In addition, a rib 671e (see Figure 10) abuts against the rear surface (back surface) of the lid 67b, creating a predetermined gap between the case 67a and the lid 67b. When the internal fan 9 is driven, air is guided to the cooler 4 (see Figure 10) through this gap.

[0047] As described above, the cooling unit 250 is located inside the chamber of the inner box 18 (see Figure 3). The return pipe 58 of the cooling unit 250 passes through the through-hole 18z (see Figure 6) formed in the inner box 18, the through-hole 5z (see Figure 6) formed in the insulation material 5, and the through-hole 11z (see Figure 6) formed in the outer plate 11 (top plate of the machine room 25) in sequence in the vertical direction, extending to the compressor 24 in the machine room 25 (see Figure 6). This eliminates the need to place the return pipe 58 in the gap between the inner box 18 and the insulation material 5, thus preventing the air in this gap from being cooled by the return pipe 58. Therefore, condensation in the gap between the inner box 18 and the insulation material 5 can be suppressed. In addition, there is no need to form the outer plate 11 (see Figure 6) in a shape that does not interfere with the return pipe 58, thus simplifying the shape of the outer plate 11 and reducing manufacturing effort and costs.

[0048] Furthermore, the return pipe 58 and the capillary tube 53 may both be routed through the through holes 18z, 5z, and 11z (see Figure 6). This reduces the number of through holes required in the inner box 18 and the insulation material 5, thereby reducing manufacturing time and simplifying the assembly of the return pipe 58 and the capillary tube 53.

[0049] Furthermore, the return pipe 58 and capillary tube 53 are pre-assembled to the cooling unit 250 by brazing (or soldering). In conventional refrigerators, the return pipe and capillary tube were brazed by workers after the cooler and other components were assembled to the housing. However, the heat transfer tubes around the cooler 4 often meander in a complex manner, making the brazing of the return pipe and capillary tube time-consuming. In contrast, in this embodiment, the return pipe 58 and capillary tube 53 are pre-assembled to the cooling unit 250, thus simplifying the assembly work of the refrigerator 1. Also, because the return pipe 58 and capillary tube 53 are included in the cooling unit 250, the work of installing the cooler 4 at a vertical distance from the inner box 18 (see Figure 3) is also made easier.

[0050] Furthermore, the drain pipe 32, which guides condensation water dripping from the cooler 4 into the gutter 30 (see Figure 3) to the evaporation tray 42 (see Figure 4) in the machine room 25, has its upstream end connected to the space 68 (see Figure 10) on the intake side of the internal fan 9 (see Figure 10), and its downstream end connected to the machine room 25 (see Figure 3). Here, the machine room 25 is connected to the atmospheric pressure space outside the refrigerator 1. Therefore, the pressure on the intake side of the internal fan 9 becomes approximately equal to atmospheric pressure. As a result, the pressure on the discharge side of the internal fan 9 becomes higher than atmospheric pressure, and consequently, the pressure in the storage chamber 3 (see Figure 3), into which the internal fan 9 sends low-temperature air, also becomes higher than atmospheric pressure. As a result, the storage chamber 3 is more easily maintained at positive pressure, making it difficult for air to enter the storage chamber 3 from the outside. Furthermore, because air from the storage room 3 can easily enter through the condensation-preventing vent 15a provided in the door 2 (see Figure 3), condensation on the inside of the door inner surface member 15 can be suppressed.

[0051] Figure 12 is a time chart showing the control state of the compressor and internal fan of the refrigerator in this embodiment, as well as the changes in storage room temperature and shelf surface temperature. Figure 12 shows the operating state of the refrigerator according to this embodiment when installed in an environment of 32°C and 70% relative humidity. As shown in Figure 12, the refrigerator 1 is controlled based on the temperature of the storage compartment 3 detected by the storage compartment temperature sensor 45 and the temperature of the cooler 4 detected by the cooler temperature sensor 46. Specifically, when the temperature of the storage compartment 3 detected by the storage compartment temperature sensor 45 reaches the cooling start temperature (Ton), the compressor 24 and the internal fan 9 are driven to start the cooling operation. When the temperature of the storage compartment 3 detected by the storage compartment temperature sensor 45 reaches the compressor stop temperature (Tcomp_off), the compressor 24 stops, ending the cooling operation, and the refrigerator transitions to a state where the internal fan 9 is driven (fan operation). Furthermore, when the temperature of the cooler 4 detected by the cooler temperature sensor 46 reaches the internal fan stop temperature (Tfan_off), the internal fan 9 is stopped, and the fan operation ends.

[0052] In Figure 12, time t0 is the time when the cooling operation begins because the temperature of the storage chamber 3, as detected by the storage chamber temperature sensor 45, reaches the cooling operation start temperature (Ton, 3°C in this embodiment). Upon starting the cooling operation, the compressor 24 is turned on, supplying refrigerant to the cooler 4, which lowers the temperature of the cooler 4 to the negative temperature range. The internal fan 9 is then turned on, supplying cold air to the storage chamber 3, causing both the temperature of the storage chamber 3 and the surface temperature of the shelves 34b to decrease to approximately the same temperature. Note that in Figure 12, the surface temperature of the shelves 34b is shown as a reference temperature.

[0053] At time t1, the storage chamber temperature sensor 45 detects that the temperature of the storage chamber 3 has reached the compressor stop temperature (Tcomp_off, 1°C in this embodiment), ending the cooling operation. The compressor 24 stops (OFF), and the internal fan 9 remains in the driven (ON) state, transitioning to a fan operation. As a result, with no refrigerant supplied to the cooler 4, the internal fan 9 drives, causing the temperature of the cooler 4 to rise due to the heat load, and both the temperature of the storage chamber 3 and the surface temperature of the shelves 34b rise. Even at this time, the temperature of the storage chamber 3 and the surface temperature of the shelves 34b are both approximately equal. The period during fan operation when the temperature of the cooler 4 remains constant at around 0°C is due to the melting of frost during that period. Stopping the compressor 24 and driving the internal fan 9 to operate the fan operation corresponds to a temperature compensation means.

[0054] At time t2, the temperature of the cooler 4 detected by the cooler temperature sensor 46 reaches the internal fan stop temperature (Tfan_off, 2°C in this embodiment), causing the internal fan 9 to stop (OFF) and enter a shutdown state. As a result, air is no longer blown into the storage chamber 3, and the temperature of the storage chamber 3 rises. On the other hand, the surface temperature of the shelf 34b rises at a slower rate due to the effects of the stored heat and natural convection in the shelf 34b and the cooler chamber 8.

[0055] At time t3, the storage chamber temperature sensor 45 detects that the temperature of the storage chamber 3 has reached the cooling operation start temperature (Ton), and the cooling operation is restarted.

[0056] As described above, when the internal fan 9 is driven, the behavior of the temperature of the storage chamber 3 detected by the storage chamber temperature sensor 45 and the surface temperature of the shelf 34b are similar and change at approximately the same temperature. Therefore, the storage chamber temperature sensor 45 can be used as a temperature estimation means to estimate the surface temperature of the shelf 34b, that is, the temperature near the bottom surface of the food placed on the shelf 34b.

[0057] Regarding the fan operation shown in Figure 12, if it is performed after the cumulative operating time of the compressor 24 reaches a predetermined time (for example, 24 hours), the internal fan stop temperature (Tfan_off) will be 2°C higher than that of normal fan operation, the fan operation will be extended, and a defrosting operation will be performed to ensure that the frost on the cooler 4 is completely melted. During the defrosting operation, power is supplied to the electric heater 60 (see Figure 6) installed at the bottom of the gas-liquid separator storage space 66, and the frost on the gas-liquid separator 54 and surrounding pipes and structures will be melted. When the defrosting operation is completed, the cumulative operating time of the compressor 24 is reset to 0. In the refrigerator 1 of this embodiment, the internal fan stop temperature (Tfan_off) is set to be 2°C higher than that of normal fan operation during the defrosting operation. However, the fan operation end temperature may be set to the same temperature as during normal fan operation, and the fan operation may be continued for a predetermined time (for example, 10 minutes) after reaching the fan operation end temperature to perform the defrosting operation.

[0058] These controls are performed by a circuit board 71 (control unit) located in a circuit board housing box 70 within the machine room 25, which is equipped with a CPU, memory such as ROM and RAM, interface circuits, etc. The circuit board 71 is connected by electrical wiring (not shown) to an external temperature sensor (not shown), an external humidity sensor (not shown), a storage room temperature sensor 45, a cooler temperature sensor 46, etc. Based on the output values ​​of each sensor, the settings of the control unit, and programs pre-recorded in ROM, the circuit board 71 controls the ON / OFF, rotational speed, and heating amount of the compressor 24, internal fan 9, external blower 29, and electric heater 60.

[0059] Figure 13 is a diagram illustrating the relationship between the position and temperature of the return piping in the refrigerator of this embodiment. The upper part of Figure 13 shows the positions of the return piping 58, the capillary tube 53, and the heat exchange section (heating section) 57 in thermal contact with them, while the lower part shows the temperature of the return piping 58 at the corresponding positions. In Figure 13, the return piping 58 is shown with a thick solid line, and the capillary tube 53 is shown with a dashed line. The horizontal axis in the lower part of Figure 13 represents the position of the return piping 58 from the inlet 58a (see Figure 8) to the outlet 58b (see Figure 6). As indicated by the arrows in the upper part of Figure 13, the refrigerant flow in the return piping 58 and the refrigerant flow in the capillary tube 53 are opposite. The return piping 58 is upstream on the inside of the refrigerator (cooler room 8, gas-liquid separator storage space 66) side, while the capillary tube 53 is upstream on the outside of the refrigerator (machine room 25) side.

[0060] As shown in Figure 13, the inlet 58a of the return pipe 58 is connected to the outlet 41a of the cooler pipe 41 (see Figure 8), and during cooling operation, the low-temperature refrigerant (basically gaseous refrigerant) that has flowed through the cooler 4 flows into it. Therefore, at position p0 of the inlet 58a of the return pipe 58, the return pipe temperature (temperature of the return pipe 58) is a sufficiently low negative temperature (in this embodiment, the return pipe temperature at position p0 is -12.0°C). Furthermore, the return pipe 58 comes into contact with the capillary tube 53 at position p1, causing the return pipe temperature to begin to rise and reach 0°C at position p2. Subsequently, as the return pipe 58 moves downstream, the return pipe temperature rises and reaches the dew point of the outside air at position p3 (in this embodiment, the return pipe temperature at position p3 is 25.8°C (dew point at 32°C, relative humidity 70%)). Finally, at position p4, the return pipe 58 reaches the communication hole 80 (in this embodiment, the return pipe temperature at position p4 is 32.2°C). Next, at position p5, it reaches the outside (machine room 25) (in this embodiment, the return pipe temperature at position p5 is 33.0°C). At position p6, the heat exchange section (heating section) 57 ends (in this embodiment, the return pipe temperature at position p6 is 33.5°C), and at position p7, it reaches the outlet 58b of the return pipe 58 (in this embodiment, the return pipe temperature at position p7 is 33.5°C), that is, the return port 24b of the compressor 24 (see Figure 6).

[0061] In this embodiment of the refrigerator 1, with position p0 as the origin, the distance to position p1 is 140 mm, to position p2 is 320 mm, to position p3 is 900 mm, to position p4 is 1400 mm, to position p5 is 1490 mm, to position p6 is 1550 mm, and to position p7 is 1800 mm. From these, the total length of the return pipe 58 (position p7-position p0) is 1800 mm, the length of the heat exchange section 57 (position p6-p1) is 1410 mm, the length L20 of the heat exchange section 57 located inside the refrigerator (position p4-p1) is 1260 mm, the length L10 of the heat exchange section 57 located inside the communication hole 80, i.e., inside the insulating wall of the insulating box 10 (position p5-p4) is 90 mm, and the length of the heat exchange section 57 located outside the refrigerator (position p6-p5) is 60 mm.

[0062] Having described the configuration of the refrigerator of this embodiment, the effects of the refrigerator of this embodiment will now be explained. The refrigerator 1 of this embodiment comprises an insulated box 10 formed with insulating material 5, and a refrigeration cycle 150 through which a refrigerant circulates. The refrigeration cycle 150 comprises a cooler 4 housed within the insulated box 10, a compressor 24, and a return pipe 58 (outlet pipe) connecting the downstream side of the cooler 4 and the upstream side of the compressor 24. The return pipe 58 is led to the outside of the insulated box 10 through a communication hole 80 (gap) in the insulated box 10. Air is present in the communication hole 80 (gap). A heat exchange section 57 (heating section) is provided that heats the portion of the return pipe 58 including the portion passing through the communication hole 80 (gap) and the portion upstream thereof. This makes it possible to provide a highly reliable refrigerator 1 that is less prone to condensation and frost formation inside the insulating wall (inside the communication hole 80) forming the insulated box 10. The reason is explained below.

[0063] Generally, the cooler that cools the inside of a refrigerator needs to be sufficiently cold relative to the internal temperature, so it operates at sub-zero temperatures. Consequently, the refrigerant entering the return pipe that returns the cooler to the compressor is also a low-temperature refrigerant at sub-zero temperatures. If this return pipe, through which the low-temperature refrigerant flows, is placed inside an insulated wall that has gaps where air exists, frost and condensation may occur. In particular, when adopting a method such as installing pre-molded or processed insulation material into the insulated wall, rather than filling the inside of the insulated wall with foamed urethane, as in the refrigerator of this embodiment, it is difficult to completely eliminate gaps where air exists. Therefore, consideration must be given to the insulated wall having gaps where air exists. Accordingly, in the refrigerator 1 of this embodiment, by providing a heat exchange section 57 that heats the portion passing through the communication hole 80 and the portion upstream thereof, the temperature of the return pipe 58 passing through the communication hole 80 can be raised, making it less likely for frost and condensation to occur in the communication hole 80.

[0064] Furthermore, the area in which the heat exchange section 57 is provided is not limited to both the portion inside the communication hole 80 and the portion upstream of the communication hole 80, but may be limited to only the portion upstream of the communication hole 80. Even in this case, frost and condensation can be less likely to occur in the communication hole 80.

[0065] Furthermore, the refrigerator 1 of this embodiment includes a refrigeration cycle 150 through which a high-temperature refrigerant discharged from the compressor 24 flows, comprising heating pipes (discharge pipe 59, radiator 50, wall heat dissipation pipe 51, condensation suppression pipe 52, connecting pipe 151, and capillary tube 53). As a means for heating the heating section (heating means), it includes a heat exchange section 57 in which the heating pipes are in thermal contact with the return pipe 58. As a result, the return pipe 58 can be heated using the piping of the refrigeration cycle 150, eliminating the need for heating means such as heaters, and making it possible to create a refrigerator 1 that is cost-effective and less prone to condensation and frost formation inside the insulated walls forming the insulated box 10.

[0066] Furthermore, in this embodiment, the refrigerator 1 has a refrigeration cycle 150 that includes a heat dissipation pipe (discharge pipe 59, radiator 50, wall heat dissipation pipe 51, condensation suppression pipe 52, connecting pipe 151) through which a high-temperature, high-pressure refrigerant flows, and a capillary tube 53 (pressure reduction pipe) that reduces the pressure of the high-temperature, high-pressure refrigerant to a low-temperature, low-pressure refrigerant. The heat exchange section 57 has the capillary tube 53, which is the pressure reduction pipe, in thermal contact with the return pipe 58. As a result, heat exchange occurs between the low-temperature return pipe 58 and the capillary tube 53, which has a smaller inner diameter than the heat dissipation pipe to obtain a pressure reduction effect. This causes the refrigerant in the capillary tube 53 to flow at a high velocity, increasing the heat transfer coefficient. This makes it easier for heat to be transferred to the return pipe 58, allowing sufficient heat exchange to be performed over a relatively short length.

[0067] Furthermore, in this embodiment, the refrigerator 1 has a length L20 (length from position p1 to position p4 in Figure 11) on the upstream side of the communication hole 80 (gap) of the heat exchange section 57 (contact section) of the return pipe 58 and the capillary tube 53 that passes through the inside of the communication hole 80 (gap). This allows the temperature of the return pipe 58 to be sufficiently raised before reaching the communication hole 80, making the refrigerator 1 less prone to condensation and frost formation inside the insulated wall forming the insulated box 10.

[0068] Furthermore, the refrigerator 1 of this embodiment is equipped with a gutter 30 at the bottom of the cooler 4, and the return pipe 58 is installed in the area projected above the gutter 30. This allows melted water from frost and condensation that forms on the low-temperature portion of the return pipe 58 inside the refrigerator, as well as condensation water, to be drained outside the refrigerator via the gutter 30, preventing it from flowing into unintended areas such as the storage compartment 3, resulting in a highly reliable refrigerator 1.

[0069] Furthermore, in this embodiment, the refrigerator 1 has a heating unit (heat exchange unit 57) located in the region formed between the cooler 4 and the gutter 30. This prevents frost or condensation formed on the heating unit from falling or dripping onto the cooler 4, blocking the flow path of the cooler 4, or freezing on the surface of the cooler 4, thus resulting in a highly reliable refrigerator 1.

[0070] Furthermore, in the refrigerator 1 of this embodiment, in the heat exchange section 57 between the return pipe 58 and the capillary tube 53, the upstream side of the refrigerant flowing through the capillary tube 53 is brought close to the air inlet surface 4a (air inlet section) of the cooler 4.

[0071] Furthermore, in this embodiment, the refrigerator 1 has multiple rows of piping forming the heat exchange section 57 located at the bottom of the cooler 4, and the downstream row of the refrigerant flow in the return piping 58 forming the heat exchange section 57 is positioned close to the fins 40 on the upstream side of the airflow in the cooler 4. Generally, the surface of the fins on the upstream side of the airflow in the cooler has a high mass transfer rate and is a region where frost easily grows. Therefore, the temperature of the return piping 58 rises on the downstream side due to heating in the heat exchange section 57. By positioning the downstream portion of the return piping 58, where the temperature has risen, close to the fins on the upstream side of the airflow in the cooler 4, excessive frost growth can be suppressed, resulting in a refrigerator 1 that is less prone to a decrease in cooling performance due to blockage of the inter-fin flow path by frost.

[0072] Furthermore, in this embodiment, the refrigerator 1 is equipped with an insulating member 90 in the heat exchange section 57 (heating section) of the return pipe 58 (see Figure 9). As a result, the heat from the heating section is less likely to be transferred to the low-temperature air inside the refrigerator, thereby suppressing the rise in the heat load inside the refrigerator and resulting in a refrigerator 1 with high energy-saving performance.

[0073] Furthermore, the refrigerator 1 of this embodiment includes an internal fan 9 that forms airflow within the storage chamber 3 formed in the insulated box 10, an air passage (air supply duct 20 and discharge ports 21a, 21b, 21c, 21d) that sends air to the storage chamber 3 when driven by the internal fan 9, a return opening 22 that returns air from the storage chamber 3 to the cooler chamber 8, a drain port 31 provided in the gutter 30, a drain pipe 32 connected to the drain port 31, and an evaporation tray 42 connected to the drain pipe 32. The drain port 31 is located downstream of the air inlet surface 4a of the cooler 4 and upstream (suction side) of the internal fan 9. As a result, even if a gap is created between the door 2 and the insulated box 10 due to the user placing food or other items between them, it is difficult for air containing a lot of moisture from outside to flow into the storage chamber 3, resulting in a refrigerator 1 that is less prone to frost and condensation forming in the storage chamber 3. The reason will be explained below.

[0074] Generally, when a fan in an air duct is driven, the upstream side (suction side) of the fan becomes negative pressure relative to the downstream side (discharge side) of the fan. In the refrigerator 1 of this embodiment, the drain port 31 is located downstream of the air inlet surface 4a of the cooler 4 and upstream (suction side) of the internal fan 9. When the internal fan 9 is driven, the drain port 31 opens into the negative pressure area upstream of the internal fan 9. As a result, when a gap is created between the door 2 and the insulated box 10, air flows from outside the refrigerator into the cooler chamber 8, which is under negative pressure, via the drain pipe 32 and the drain port 31. This creates a flow in which air flows out from the storage chamber 3, which is under positive pressure relative to atmospheric pressure and is downstream (discharge side) of the internal fan 9, through the gap in the door 2. This makes it difficult for air containing a lot of moisture to flow into the storage chamber 3 from outside, resulting in a refrigerator 1 that is less prone to frost and condensation in the storage chamber 3.

[0075] Furthermore, the refrigerator 1 of this embodiment is equipped with a heat sink 50 (condenser), a compressor 24, an evaporation tray 42, and an external blower 29 in a machine room 25 located at the bottom outside the insulated box 10. The external blower 29 is configured to cool the heat sink 50 and the compressor 24 by drawing in and exhausting air from a suction port 27 and an exhaust port 28 located on the front of the machine room 25, and a drain port 31 is located downstream of the external blower 29. As a result, the external blower 29 drives a positive pressure near the evaporation tray 42. Therefore, even if a gap is created between the door 2 and the insulated box 10 due to the user placing food or other items between them, air flows from outside into the cooler compartment 8 via the drain pipe 32 and drain port 31, and air flows out from the storage compartment 3 downstream (discharge side) of the internal fan 9 through the gap in the door 2. This makes it difficult for air containing a lot of moisture to flow into the storage compartment 3 from outside, resulting in a refrigerator 1 that is less prone to frost and condensation in the storage compartment 3.

[0076] The refrigerator 1 of this embodiment comprises a cooler 4, a storage compartment 3 in the refrigeration temperature range, an internal fan 9 that forms airflow within the storage compartment 3, a door 2 that can close the front opening of the storage compartment 3, a fixed or removable shelf (shelf 34b) located within the storage compartment 3, a food placement surface 34c, and a cooler compartment 8 that includes the area approximately directly below the placement surface 34c, and is equipped with a temperature compensation means for raising the temperature of the placement surface 34c. This makes it possible to provide a highly reliable refrigerator 1 that suppresses the freezing of food stored in the storage compartment 3 in the refrigeration temperature range. The reasons will be explained below.

[0077] Generally, even when cooling a storage room in the refrigeration temperature range, it is necessary to lower the cooler temperature to a negative temperature in order to sufficiently cool the storage room, and consequently, the temperature inside the cooler room 8 also becomes negative. On the other hand, various foods can be stored on the food placement surface formed at the top of the cooler room. In this case, if the food on the placement surface is a food with high thermal insulation properties (low thermal conductivity) (for example, bread), the temperature near the bottom surface of the food (the surface in contact with the placement surface) will drop, and freezing may occur even if the storage room temperature is at the refrigeration temperature. As a means of solving this problem, it is conceivable to improve thermal insulation by placing a highly insulating material between the cooler room and the placement surface or by increasing the thickness of the insulating material. However, even if thermal insulation is improved, sufficient effect may not be obtained when insulating food is placed on it, and the food may freeze. Therefore, the refrigerator 1 of this embodiment is equipped with means (temperature compensation means) to raise the temperature of the food placement surface 34c (upper surface of shelf 34b) (see Figure 12), and is a highly reliable refrigerator 1 that suppresses the freezing of food stored in the storage chamber 3 in the refrigerated temperature range.

[0078] Furthermore, in this embodiment, the refrigerator 1 uses a temperature compensation means to drive the internal fan 9 to blow air into the storage compartment 3 when no refrigerant is supplied to the cooler 4 (see Figure 12). As a result, the temperature of the cooler 4 rises when no refrigerant is supplied, which also raises the temperature of the cooler compartment 8. This makes it more difficult for the food to be cooled from below the food placement surface 34c, effectively raising the temperature of the food placement surface 34c and preventing the food from freezing.

[0079] Further, the refrigerator 1 of the present embodiment arranges a flow path 76 between the cooler chamber 8 and the food placement surface 34c as temperature compensation means (see FIG. 7). In a state where the refrigerant is not supplied to the cooler 4, the internal fan 9 is driven to blow air into the storage chamber 3 (see FIG. 12). Thereby, in a state where the internal fan 9 is driven with the refrigerant supplied to the cooler 4, an air current is generated in the flow path 76, so that the cooling by heat conduction from the cooler chamber 8 is alleviated. Further, in a state where the refrigerant is not supplied to the cooler 4, the air current with an increased temperature flows through the flow path 76, so that the temperature of the food placement surface 34c can be effectively raised. Therefore, an operation with a lower risk of the food reaching freezing can be implemented.

[0080] Further, the refrigerator 1 of the present embodiment is configured such that the gap dimension L1 of the flow path R1 formed behind the placement surface 34c and the gap dimension L2 of the flow path R2 formed in front of the placement surface 34c satisfy L1 < L2 (see FIG. 7). Thereby, the main flow of the air current flowing in the storage chamber 3 can be made to flow toward the door 2 side in front of the placement surface 34c. Conversely, if the main flow is made to flow through the flow path R1 behind the placement surface 34c, it becomes impossible to cool well the region close to the door 2 where the temperature is likely to rise due to heat intrusion. By adopting the above configuration, the entire storage chamber 3 can be cooled well.

[0081] Further, the refrigerator 1 of the present embodiment is configured such that the gap dimension L1 of the flow path R1 formed behind the food placement surface 34c and the gap dimension L3 of the flow path 76 formed below the food placement surface 34c satisfy L1 < L3. Thereby, since the flow path R1 becomes narrower than the flow path 76, excessive air current does not flow through the flow path 76, and the entire storage chamber 3 is likely to be cooled well.

[0082] Furthermore, the refrigerator 1 of this embodiment has a storage chamber 3 formed from above to the front of the cooler chamber 8, and a return opening 22 for returning the air from the storage chamber 3 to the cooler chamber 8 is opened to the front, and a directional means is provided to direct the air so that it has a velocity component toward the upper surface side of the cooler chamber 8. For example, as a directional means, the relationship between the front opening dimension (vertical opening dimension) L4 and the depth opening dimension (horizontal opening dimension) L5 of the return opening 22 is set to L4 > L5 (see Figure 7). As a result, the air that has flowed through the storage chamber 3 and whose temperature has risen flows toward the upper surface side of the cooler chamber 8, making it difficult for the temperature of the food placement surface 34c above to drop.

[0083] Furthermore, in this embodiment, the refrigerator 1 has a cooling chamber 8 equipped with a bypass channel 77 on the upper side of the cooling chamber 4 that bypasses the cooling chamber 4 (see Figure 7). As a result, some of the air that has flowed through the storage chamber 3 and whose temperature has risen flows through the bypass channel 77, making it more difficult for the temperature of the food placement surface 34c above to drop.

[0084] Furthermore, the refrigerator 1 of this embodiment is equipped with a temperature estimation means (storage chamber temperature sensor 45) for estimating the food temperature in the storage chamber 3. When the temperature estimation means estimates a decrease in food temperature, the temperature compensation means raises the temperature of the food placement surface 34c (see the fan operation in Figure 12). This makes it possible to suppress food freezing more efficiently and reliably.

[0085] Furthermore, in this embodiment, the refrigerator 1 has a storage chamber temperature sensor 45 positioned in the storage chamber 3, which is formed on the upper part of the mounting surface 34c. This makes it possible to more reliably estimate the risk of food freezing.

[0086] Furthermore, the refrigerator 1 of this embodiment includes a cooling unit 250 provided on the inside of the inner box 18 of the insulated box body 10, which is constructed including an insulating material 5. The cooling unit 250 has a cooler 4, an internal fan 9, and a housing 67. The cooler 4 and the internal fan 9 are housed in the housing 67. This unitization makes assembly into the refrigerator 1 easier.

[0087] Furthermore, the refrigerator 1 of this embodiment has a cooling unit 250 which includes a return pipe 58 connected to the suction side of the compressor 24 and a capillary tube 53 connected to the upstream side of the cooler 4. Both the return pipe 58 and the capillary tube 53 pass through through holes 18z and 5z provided in the inner box 18 and the insulation material 5. This prevents condensation from forming in the gap between the inner box 18 and the insulation material 5.

[0088] Furthermore, the refrigerator 1 of this embodiment has a cooling unit 250 which includes a shell-shaped gas-liquid separator 54 connected downstream of the cooler 4, and a heater 54a installed on the gas-liquid separator 54. This makes it possible to suppress condensation on the gas-liquid separator 54.

[0089] Furthermore, the refrigerator 1 of this embodiment includes a gutter 30 provided on the lower side of the cooler 4 and a drain pipe 32 connected to the gutter 30. Part of the gutter 30 or the drain pipe 32 passes through through holes 18v and 5v provided in the inner box 18 and the insulation material 5. The upstream end of the drain pipe 32 communicates with the space on the intake side of the internal fan 9, and the downstream end of the drain pipe 32 communicates with the machine room 25 where the compressor 24 is installed. As a result, even if a gap is formed between the door 2 and the insulated box 10, it becomes difficult for moist air to enter the storage room 3, and condensation on the inner box 18 can be suppressed.

[0090] It should be noted that the present invention is not limited to the embodiments described above, and various modifications are included. For example, the refrigerator of this embodiment has one storage compartment for the refrigerated temperature range, but it can also have multiple storage compartments for the refrigerated temperature range, or the configuration of the present invention can be applied to the refrigerated storage compartment of a refrigerator that has both a freezing temperature storage compartment and a refrigerated temperature storage compartment, or the configuration of the present invention can be applied when setting the refrigerated temperature of a storage compartment that can be switched between the refrigerated temperature range and the freezing temperature range. Furthermore, an electric heater may be used as a temperature compensation means to more reliably prevent food from freezing. In other words, the embodiments described above have been explained in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those that have all the configurations described.

[0091] Figure 14 is a top view of the refrigerator 1 according to this embodiment with the top plate 12 removed. Figure 15 is a front view of the door sensor 96. As shown in Figure 14, the main wiring 98, which is located in the storage compartment 3 and extends from the control system board, is guided between the top plate 12 and the ceiling panel 13. This main wiring 98 reaches the space between the insulation material 5 and the outer panel 11 through a hole (not shown) provided in the wall of the storage compartment 3, extends upward along this space, and is guided between the top plate 12 and the ceiling panel 13. The main wiring 98 is also connected to the interior light board 97 located on the front center side of the ceiling panel 13. The interior light board 97 is connected to relay lines 94 (94L, 94R) that transmit signals to the main wiring 98. The main wiring 98 is used not only for signal exchange with the relay lines 94 but also with the interior light board 97, but if the only purpose is to detect the opening and closing of the door 2, it is not necessarily required to connect the main wiring 98 and the relay lines 94 via the interior light board 97; they may be connected directly.

[0092] As shown in Figure 15, a door sensor 96 is provided on the front edge of the ceiling panel 13, which includes Hall sensors 961 and 962 for detecting the opening and closing of the door 2, and a terminal 963 (see Figure 16 below) for outputting signals from the Hall sensors 961 and 962. The relay line 94 is connected to terminal 963. The door sensor 96 can be positioned on either the left or right end of the front edge of the ceiling panel 13, in the area 96L or 96R, which is on the side opposite the hinge. In this embodiment, the rotating door 2 has a hinge 95R at its right end, which serves as the axis of rotation, so the door sensor 96 is positioned in the left end area 96L, which is the side opposite the hinge. The door 2 is equipped with a permanent magnet 2M (see Figure 16 below) at the end opposite the hinge, and when this approaches the Hall sensor, the door sensor 96 detects that the door is closed. This allows the door sensor 96 to be installed on the non-hinge side of the refrigerator 1, regardless of whether the door 2 opens to the right or left, making it easier to detect when the door 2 is opened or closed.

[0093] Furthermore, the door sensor 96 uses one of two Hall sensors 961, 962, which are arranged side by side, on the non-hinge side. Figure 16 is a schematic diagram of a right-opening door with a hinge 95R on the right side. Figure 17 is a schematic diagram of a left-opening door with a hinge 95L on the left side. Note that the main wiring 98 and relay wire 94 are each made up of bundled wires, and each wire is shown separately, so the actual width dimensions are considerably exaggerated.

[0094] Terminal 963 is a terminal with at least two pins corresponding to the signals of Hall sensors 961 and 962, respectively. Four pins are shown in Figure 16. In the right-opening example in Figure 16, in order to use only the signal of the Hall sensor 961 on the non-hinge side of the two Hall sensors 961 and 962, the relay line 94L is equipped with wiring 941L that connects to the pin corresponding to the Hall sensor 961 on the non-hinge side, but does not have wiring 941R that connects to the pin corresponding to the Hall sensor 962 on the hinge side.

[0095] On the other hand, in the left-opening example in Figure 17, in order to use only the signal from the Hall sensor 962 on the non-hinge side of the two Hall sensors 961 and 962, the relay line 94R is equipped with a wire 941R that connects to the pin corresponding to the Hall sensor 962 on the non-hinge side, but does not have a wire 941L that connects to the pin corresponding to the Hall sensor 961 on the hinge side.

[0096] This allows for the use of only one type of main wiring 98 that runs over a long distance between the insulation material 5 and the outer panel 11, while using two different types of relay wires 94. Relay wires 94 can be replaced simply by removing the top plate 12, but the main wiring 98 requires the removal of the outer panel 11, making replacement difficult. Therefore, by using a single type of main wiring 98 and differentiating the relay wires 94, it becomes easier to correct incorrect assembly.

[0097] Incidentally, the refrigerator 1 of this embodiment is equipped with a control panel (not shown) inside the storage compartment 3. By operating the control panel, the user can make various settings, such as changing the temperature setting of the storage compartment 3. Since the refrigerator 1 of this embodiment has only one storage compartment, the control panel of this embodiment is equipped with, for example, only two operation buttons.

[0098] Maintenance and repairs of refrigerator 1 may be performed by a service person. There are known models of refrigerator 1 that require a specific command to be entered into the control panel in order to start a service mode that is convenient for the service person to provide service. In the refrigerator 1 of this embodiment, if such a command were to be prepared, it is conceivable that it would either become an extremely complicated command due to the limited number of buttons, or it would become a command that is simple enough that the user might accidentally enter the specified command.

[0099] Therefore, in the refrigerator 1 of this embodiment, the condition for starting the service mode is set to "operating the control panel while the door sensor 96 is detecting that the door 2 is closed." In this way, the starting condition is not based on the control panel, and moreover, it includes an action that the user would not normally perform, thus eliminating the above-mentioned inconveniences.

[0100] Specifically, in addition to the permanent magnet 2M on door 2, a service person prepares a permanent magnet and places it close to the Hall sensor 961 or 962 of the door sensor 96 that is in use, while door 2 is open. This allows the door sensor 96 to (incorrectly) detect that door 2 is closed, even though door 2 is actually open. Since the control panel is located inside the storage compartment 3, under normal refrigerator usage, the control panel would not be operated while door 2 is closed. Therefore, this prevents the user from unintentionally activating service mode.

[0101] The condition "In a refrigerator 1 equipped with a control panel in the storage compartment 3, the condition for starting service mode is to have the door sensor 96 of the door 2 that closes the storage compartment 3 detect that it is closed, and then input a predetermined command into the control panel" is particularly effective when the control panel has a small number of buttons, for example, three or fewer.

[0102] Figure 18 is a rear view of the refrigerator according to this embodiment with the outer panel 11 removed. As shown in Figure 18, when the outer panel 11 of the refrigerator 1 is removed, the insulation material 5 is exposed. The insulation material 5 is divided into insulation material 5a installed on the ceiling, insulation material 5b installed in the center of the back, insulation material 5c installed at the bottom of the back, insulation material 5d installed on the left side, and insulation material 5e installed on the right side. Each joint 501 between the insulation materials 5a to 5e is covered with metal tape, such as aluminum tape 200, and joined together. By covering the joints 501 with aluminum tape, which has a high effect in suppressing the transmission of water vapor, it is possible to suppress condensation that occurs when water vapor that has entered the outside of the insulation material 5 moves to the inside of the refrigerator where the temperature is lower. In addition, the main wiring 98 that is routed from the ceiling to the machine room 25 is also covered with aluminum tape 200, making it difficult for condensation to occur around the main wiring 98.

[0103] Furthermore, on the inner side (insulation material 5 side) of the outer panel 11, wall-mounted heat dissipation pipes 51, which meander in a zigzag pattern along the back, are fixed to the wall-mounted heat dissipation pipes 51 by metal tape, such as aluminum tape 201, which is attached to the wall-mounted heat dissipation pipes 51 (the edge of the aluminum tape 201 is shown with a short dashed line). The width of this aluminum tape 201 is greater than the width of the heat dissipation pipes 51. By fixing the wall-mounted heat dissipation pipes 51 to the outer panel 11 with aluminum tape, which is a metal with high thermal conductivity, heat is transferred well from the wall-mounted heat dissipation pipes 51 to the outer panel 11 via the aluminum, improving heat dissipation performance. In addition, the aluminum tape 200 and the aluminum tape 201 are arranged so that they partially overlap, and when the outer panel 11 is attached, parts of the aluminum tape 200 and the aluminum tape 201 are in approximate contact. By arranging the aluminum tape 200 and aluminum tape 201 in this manner, the heat released from the wall heat dissipation pipe 51 flows through the aluminum tape 201 and is transferred to the aluminum tape 200, effectively heating the joint 501 between the insulation materials 5a and 5e and around the main wiring 98. This makes condensation less likely to occur around the joint 501 and the main wiring 98.

[0104] Furthermore, grooves (not shown) are formed in the insulation material 5 at the position opposite the wall-mounted heat dissipation pipe 51 fixed to the outer panel 11 and at the position where the main wiring 98 is installed. When the outer panel 11 is attached, the wall-mounted heat dissipation pipe 51 and the main wiring 98 are housed in these grooves. This prevents deformation of the outer panel 11 and the insulation material 5 when the outer panel 11 is attached.

[0105] This application encompasses the following technical ideas. [Note 1-1] It comprises an insulated box body formed with insulating material and a refrigeration cycle through which a refrigerant circulates, The refrigeration cycle comprises a cooler housed inside the insulated box, a compressor housed outside the insulated box, and an outlet pipe connecting the downstream side of the cooler and the upstream side of the compressor. The outlet pipe is led out of the heat insulation box through the gap of the heat insulation box body, air exists in the gap, and a heating part is arranged to heat a part of the outlet pipe passing through the gap and a part upstream of this part, or a part upstream of the part of the outlet pipe passing through the gap. [Appendix 1-2] The refrigeration cycle includes a heating pipe through which high-temperature refrigerant discharged from the compressor flows. The refrigerator according to Appendix 1-1, wherein the heating part is a heat exchange part in which the heating pipe is in thermal contact with the outlet pipe. [Appendix 1-3] The refrigeration cycle includes a heat dissipation pipe through which high-temperature and high-pressure refrigerant flows, and a capillary tube for decompressing the high-temperature and high-pressure refrigerant into low-temperature and low-pressure refrigerant, as the heating pipe. The refrigerator according to Appendix 1-2, wherein the heat exchange part is in thermal contact with the capillary tube on the outlet pipe. [Appendix 1-4] The refrigerator according to Appendix 1-3, wherein, among the contact parts of the outlet pipe and the capillary tube, the relationship between the length L10 passing through the inside of the gap and the length L20 on the upstream side of the outlet pipe in the gap is L10 < L20. [Appendix 1-5] A drain is provided below the cooler. The refrigerator according to Appendix 1-1, wherein the outlet pipe is installed in the upper projection area of the drain. [Appendix 1-6] The refrigerator according to Appendix 1-5, wherein the heating part is arranged in the area formed between the cooler and the drain. [Appendix 1-7] The pipes forming the heat exchange part are arranged in multiple rows at the lower part of the cooler, and the row on the downstream side of the refrigerant flow of the outlet pipe forming the heat exchange part is close to the fins on the upstream side of the air flow of the cooler. [Appendix 1-8] The refrigerator according to Appendix 1-3, wherein a heat insulation member is arranged in the heat exchange part. [Appendix 1-9] The refrigerator according to Appendix 1-5, further comprising: an internal blower that forms an airflow in a storage chamber formed in the insulated box body; an air passage that sends air to the storage chamber by driving the internal blower; a return opening that returns air from the storage chamber to the cooler chamber; a drain port provided in the gutter; a drain pipe connected to the drain port; and an evaporation tray connected to the drain pipe, wherein the drain port is located in a region downstream of the air inlet surface of the cooler and upstream of the internal blower. [Appendix 1-10] A machine room located at the bottom of the insulated box is equipped with a heat sink, a compressor, an evaporation tray, and an external blower. The external blower draws in and exhausts air from suction and exhaust ports located on the front of the machine room to cool the heat sink and the compressor. The refrigerator according to Appendix 1-9, characterized in that the drain outlet is connected to the downstream side of the external blower. [Appendix 1-11] The refrigeration cycle includes heating pipes through which a high-temperature refrigerant discharged from the compressor flows, and which are routed along the outside of the insulated box. The heating pipe is provided with a metal tape attached to the heating pipe along the heating pipe, The aforementioned insulated box comprises a plurality of pre-formed insulating materials and another metal tape that joins the joints of adjacent insulating materials, The refrigerator according to Appendix 1-1, characterized in that the metal tape and the other metal tape are in at least partial contact. [Appendix 1-12] The aforementioned insulated box has an opening that opens and closes, and a door that rotates on a hinge as an axis, The system includes a door sensor in which two sensors for detecting the opening and closing of the aforementioned door are arranged side by side in the left-right direction, The refrigerator according to Appendix 1-1, characterized in that the door sensor detects the opening and closing of the door using the sensor furthest from the hinge among the two sensors. [Appendix 1-13] A control panel is located in the storage room at the back of the aforementioned opening. The refrigerator according to Appendix 1-12, characterized in that a service mode can be executed by performing a predetermined operation on the control panel when the door sensor detects that the door is closed. [Explanation of Symbols]

[0106] 1. Refrigerator 2 doors 3 Storage Room 4 Cooler 5. Insulation 5v through hole (second through hole) 5z Through hole (1st through hole) 6. Door second insulation 7. Door Insulation 8 Cooler room 9. Interior fan (interior blower) 10 Insulated box 11 Outer panels 11v through hole 11z through hole 12 Top Plate 13 Ceiling panels 14 Front Panel 15 Door interior component 16a Upper member 16b Bottom member 17 Front edge steel plate 18 Inner box 18v through hole (second through hole) 18z Through hole (1st through hole) 19. Sealing member 20 Air supply duct 21a, 21b, 21c, 21d outlet 22 Return opening 24 Compressor 25 Machine room 27 Suction port 28 Exhaust vents 29 External blower 30 Gutters 31 Drain 32 Drain pipe 33 shelves 34a, 34b shelves 34c Mounting surface 35 Container 45 Storage room temperature sensor 50 Heatsink 51 Wall-mounted heat dissipation piping 52 Condensation suppression piping 53 Capillary tube 54 Gas-liquid separator 54a Heater 55 Hair Dryer 57 Heat exchange section 58. Return piping (outlet piping) 59 Discharge piping 60 Electric Heaters 66. Storage space for gas-liquid separator 67 containment units 68 Space 70 Circuit board storage boxes 76 channels 77 Bypass channel 80 Communication hole 90 Insulation material 150 Refrigeration Cycle 151 Connecting pipes 250 Cooling Units L1, L2, L3 Gap dimensions L9 Gap Dimension (Gap)

Claims

1. The apparatus comprises a cooler, a storage chamber for refrigerated temperatures, an internal blower for creating airflow within the storage chamber, a door capable of closing the front opening of the storage chamber, fixed or removable shelves arranged within the storage chamber, a food placement surface, a cooler chamber for housing the cooler, which includes an area substantially directly below the food placement surface, and a temperature compensation means for raising the temperature of the aforementioned placement surface. As the temperature compensation means, when no refrigerant is supplied to the cooler, air is blown into the storage chamber. A refrigerator comprising a storage chamber formed from above to the front of the cooler chamber, a return opening opening forward for returning the air from the storage chamber to the cooler chamber, and a directional means for directing the air to have a velocity component toward the upper surface side of the cooler chamber.

2. The refrigerator according to claim 1, characterized in that, as the temperature compensation means, a flow path is provided between the cooler chamber and the aforementioned mounting surface, and air is blown into the storage chamber while no refrigerant is supplied to the cooler.

3. The refrigerator according to claim 2, characterized in that the gap dimension L1 of the flow channel formed behind the mounting surface and the gap dimension L2 of the flow channel formed in front of the mounting surface satisfy L1 < L2.

4. The refrigerator according to claim 2, characterized in that the gap dimension L1 of the flow channel formed behind the mounting surface and the gap dimension L3 of the flow channel formed below the mounting surface satisfy L1 < L3.

5. The refrigerator according to claim 2, characterized in that the cooling chamber is provided with a bypass channel on the upper side of the cooling unit that bypasses the cooling unit.

6. The storage chamber is equipped with a temperature estimation means for estimating the food temperature, The refrigerator according to claim 1, characterized in that, when a decrease in the food temperature is estimated based on the temperature estimation means, the temperature compensation means raises the temperature of the aforementioned surface.

7. The refrigerator according to claim 6, characterized in that, as the temperature estimation means, a temperature sensor is placed in the storage chamber formed on the upper part of the aforementioned mounting surface.

8. It is equipped with a cooling unit located on the inside of the inner box of an insulated box body that includes insulating material, The cooling unit comprises the cooler, the internal blower, and the housing. The refrigerator according to claim 1, characterized in that the cooler and the internal blower are housed in the housing.

9. The cooling unit includes an outlet pipe connected to the suction side of the compressor and a capillary tube connected to the upstream side of the cooler. The refrigerator according to claim 8, characterized in that both the outlet pipe and the capillary tube pass through the first through-hole provided in the inner box and the insulating material.

10. The refrigerator according to claim 8, characterized in that the cooling unit comprises a shell-shaped gas-liquid separator connected downstream of the cooler, and a heater installed in the gas-liquid separator.

11. A trough provided on the lower side of the cooler, The system includes a drain pipe connected to the aforementioned gutter, A portion of the gutter or the drain pipe penetrates the second through-hole provided in the inner box and the insulating material. The upstream end of the drain pipe is in communication with the space on the suction side of the internal blower. The refrigerator according to claim 9, characterized in that the downstream end of the drain pipe is connected to a machine room where the compressor is installed.

12. The cooler is provided with a trough at its lower part, It is provided with a return opening that connects the storage chamber and the cooler chamber that houses the cooler, The refrigerator according to claim 1, characterized in that at least a portion of the gutter is located between the cooler and the return opening, and a gap L9 of 1 mm or more is provided between it and the cooler.

Images