JP5909623B2 - refrigerator - Google Patents

Description

  The present invention relates to a refrigerator having a high energy saving effect.

  FIG. 7 is a longitudinal sectional view of a basic structure of a freezer compartment of a conventional refrigerator.

  As shown in FIG. 7, the refrigerator box 10 includes a vacuum heat insulating material 50, 52, 53, 55 disposed in a heat insulating wall formed by the outer box 11 and the inner box 13, and the outer box 11, the inner box 13, and the inner box 13. The box 13 and the vacuum heat insulating materials 50, 52, 53, and 55 can be bonded to each other, and are configured to have a foam heat insulating material 12 such as urethane having an adhesive force.

  In the inner box 10, there are a refrigerated temperature chamber 14 having a set temperature of 10 ° C. or less having a vegetable room and a chilled chamber (not shown), and a freezing temperature chamber having a set temperature of −16 ° C. to −30 ° C. having an ice making room and a quick freezer 15, and each room is partitioned by a front partition 16 and a partition wall 17.

  A door body 30 that closes the front face of the opening so as to be openable and closable is provided on the front face of the refrigeration temperature chamber 14. This door body 30 can be bonded to the vacuum heat insulating material 52 installed in the heat insulating wall formed by the outer box 31 and the inner box 33, and to the outer box 31, the inner box 33 and the vacuum heat insulating material 50. It is configured to have a foam heat insulating material 32 such as urethane having an adhesive force.

  The front surface of the opening of the freezing temperature chamber 15 is provided with a door body 35 that closes the front surface of the opening so as to be opened and closed. This door body 35 can be bonded to the vacuum heat insulating material 54 installed in the heat insulating wall formed by the outer box 36 and the inner box 38, and to the outer box 36, the inner box 38 and the vacuum heat insulating material 54. It is configured to have a foam heat insulating material 37 such as urethane having adhesive strength to itself.

  Although not shown in FIG. 7, the front of each storage chamber is closed by an independent door. For example, the ice making chamber and the quick freezing chamber are partitioned by a member corresponding to the front partition 16. The door is received by the front partition 16 equivalent member. In addition, the storage rooms having different temperature zones are partitioned by a member corresponding to the partition wall 17, and the member corresponding to the partition wall 17 has a heat insulating structure.

  In addition, a lower machine chamber is formed below the freezing temperature chamber 15 via a heat insulating wall, and a compressor 40 is installed.

  These vacuum heat insulating materials 50, 52, 52, 53, 54, and 55 can realize higher heat insulating performance than the foam heat insulating materials 12, 32, and 37, for example, heat conduction of the foam heat insulating material 12 on the box 10 side. While the rate is about 0.016 W / mK and the thermal conductivity of the foam insulation 32 and 37 on the door body side is about 0.018 W / mK, the vacuum insulation 50, 52, 52, 53, 54 and 55 The thermal conductivity can be about 0.002 W / mK to about 0.003 W / mK.

  Accordingly, assuming that the heat insulating wall area where heat leakage occurs is constant, a vacuum heat insulating material having a thickness dimension of about 1/5 to 1/9 of the heat insulating wall thickness formed only of a foam heat insulating material such as urethane is provided. If used, the amount of heat leakage from the heat insulating wall can be set to be equal.

  The vacuum heat insulating materials 50, 52, 52, 53, 54, 55 are installed on each surface in the heat insulating wall around the refrigeration temperature chamber 14 and in the heat insulating wall around the refrigeration temperature chamber 15, as shown in FIG. ing.

  As for these vacuum heat insulating materials, the volume of the vacuum heat insulating material which occupies the heat insulating wall volume formed by the outer box 11 and the inner box 13 as the temperature difference between the refrigerator internal temperature and the box outer surface ambient temperature increases. The rate is set large.

For example, assuming that the heat insulation wall area around the refrigeration temperature chamber 14 and the heat insulation wall area around the refrigeration temperature chamber 15 are the same area, the vacuum heat insulating material 50 installed in the heat insulation wall thickness Tr around the refrigeration temperature chamber 14; When the thickness of 52, 52 is the tr dimension, and the thickness of the vacuum heat insulating materials 53, 54, 55 installed in the heat insulating wall thickness Tf around the freezing temperature chamber 16 is the tf dimension,
tf / Tf> tr / Tr
It is comprised so that it may become.

  That is, the larger the temperature difference between the temperature inside the box and the ambient temperature on the outer surface of the box body, the larger the volume ratio of the vacuum heat insulating material to the heat insulating wall volume formed by the outer box 11 and the inner box 13 is set. is there.

  In this way, by setting a larger volume ratio of the vacuum heat insulating material in the heat insulating wall volume formed by the outer box and the inner box, the larger the temperature difference between the internal temperature and the box outer surface ambient temperature, It has been proposed to provide a refrigerator that can promote energy saving operation and improve energy saving performance as a whole (see, for example, Patent Document 1).

JP 2006-189207 A

  However, the above-described conventional configuration specializes in how heat absorbed by heat exchange between the outside air and the outer box surface is not increased to reach the interior by increasing heat insulation. No consideration is given to replacement, that is, to reduce the amount of heat absorbed from the outer box surface itself. In particular, the condenser installed in the lower machine room at the lower part of the refrigerator is air-cooled by an air-cooling fan because it becomes hotter than the outside air during the cooling operation, but the exhaust at that time is along the outer box surface Flows upward. Since the high-temperature updraft exchanges heat with the outer box surface, the amount of heat absorbed from the outer box surface is large.

  The present invention solves the above-described conventional problems, and provides a refrigerator that reduces heat absorption by suppressing heat exchange on the surface of the outer box, thereby improving cooling efficiency and reducing power consumption. With the goal.

In order to solve the above-described conventional problems, the refrigerator of the present invention includes an inner box and an outer box, a heat insulating box body including a heat insulating material between the inner box and the outer box, and the heat insulating box body. A lower machine room configured in a lower part of the machine, a condenser installed in the lower machine room, an air cooling fan for air-cooling the condenser, a heat-insulating door for opening and closing an opening front of the heat-insulating box, and the heat insulation A storage chamber of a plurality of different temperature zones formed by a box and the heat insulating door is provided, and the condenser that is hotter than the outside air during operation is air-cooled by the air-cooling fan, and the exhaust that has become hot is A heat absorption suppression shape that suppresses heat absorption from high-temperature exhaust is provided on the surface of the outer box of the heat insulation box that circulates, and the heat absorption suppression shape includes the bottom surface of the outer box of the heat insulation box , and cooling. an outer packaging surface of the vessel is facing the cooling chamber disposed, convex toward the outside air A, the convex upper flow and the width direction perpendicular caused by the negative pressure generated by operation of the lower machine room the air-cooling fan provided downstream of rising air, to generate a region where the flow velocity is slow, thermal The transmission rate is reduced .

  As a result, the amount of heat absorbed from the outer box surface can be reduced.

The refrigerator of the present invention can provide a refrigerator with improved cooling efficiency and reduced power consumption by reducing the amount of heat absorbed from the outer box surface.

The longitudinal cross-sectional view of the refrigerator in Embodiment 1 of this invention Cross-sectional view of the freezer compartment of the refrigerator in Embodiment 1 of the present invention Cooling chamber enlarged sectional view of the refrigerator in Embodiment 1 of the present invention The convex-shaped expanded sectional view of the outer case surface of the refrigerator in Embodiment 1 of this invention The expanded sectional view which shows the dimension of the convex shape of the outer case surface of the refrigerator in Embodiment 1 of this invention The lower expanded sectional view of the freezer compartment of the refrigerator in Embodiment 2 of the present invention. Sectional view of the freezer compartment of a conventional refrigerator

Invention of Claim 1 is comprised by the inner box and the outer box, the heat insulation box provided with the heat insulating material between the said inner box and the said outer box, and the lower part comprised by the lower part of the said heat insulation box A machine room, a condenser installed in the lower machine room, an air-cooling fan for air-cooling the condenser, a heat-insulating door that opens and closes an opening front of the heat-insulating box, the heat-insulating box and the heat-insulating door A storage chamber of a plurality of different temperature zones formed by the above, the condenser that is hotter than the outside air during operation is air-cooled by the air-cooling fan, The outer box surface is provided with an endothermic suppression shape that suppresses heat absorption from high-temperature exhaust, and the endothermic suppression shape is the cooling of the outer box bottom surface of the heat insulating box and a cooler. the chamber facing the outer box surface has a convex shape toward the outside air, the lower machine chamber of the Above the flow and the width direction perpendicular caused by the negative pressure generated by operation of the cold fan provided with the convex downstream updraft to generate a region in which the flow velocity is slowed, by having reduced heat transfer coefficient The amount of heat absorbed from the surface of the outer box can be reduced, the cooling efficiency can be improved, and a refrigerator with reduced power consumption can be provided.

According to a second aspect of the present invention, in the first aspect of the present invention, a plurality of the convex shapes are formed on the same surface of the outer box surface of the heat insulating box, so that the flow velocity is slow behind the convex shape. More areas can be generated, and the heat transfer coefficient in the area where the flow rate is slowed down, so the amount of heat absorbed from the outer box surface can be reduced, improving the cooling efficiency and consequently reducing the power consumption. Can be reduced.

The invention according to claim 3 is the invention according to claim 1 or 2 , wherein at least a part of the convex shape is formed on the surface of the outer box facing the storage chamber having the lowest set temperature among the storage chambers. By providing, a greater effect of reducing the amount of absorbed heat can be obtained, and the cooling efficiency can be improved. As a result, the amount of power consumption can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, detailed description of the same configurations as those of the conventional example will be omitted. The present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a longitudinal sectional view of the refrigerator according to Embodiment 1 of the present invention. FIG. 2 is a cross-sectional view of the freezer compartment of the refrigerator according to Embodiment 1 of the present invention. FIG. 3 is an enlarged cross-sectional view of the cooling chamber of the refrigerator in the first embodiment of the present invention. FIG. 4 is an enlarged sectional view of a convex shape on the surface of the outer box of the refrigerator in the first embodiment of the present invention. FIG. 5 is an enlarged cross-sectional view showing the dimensions of the convex shape of the outer box surface of the refrigerator in the first embodiment of the present invention.

  In FIG. 1, a heat insulating box 101 of a refrigerator 100 includes an outer box 102 mainly using a steel plate and an inner box 103 molded of a resin such as ABS, and the inside thereof is made of, for example, hard foam urethane or the like. Filled with foam insulation, insulated from the surroundings, divided into a plurality of storage rooms. The refrigerator compartment 104 is arranged at the top, the vegetable compartment 105 is arranged below the refrigerator compartment 104, and the freezer compartment 106 is arranged at the bottom.

  The front opening of each storage room is closed by heat insulating doors 117, 118, and 119 that are pivotally supported on the refrigerator main body.

  The refrigerator compartment 104 is normally set to 1 ° C. to 5 ° C. at the lower limit of the temperature at which it does not freeze for refrigerated storage, and the vegetable compartment 105 is set to 2 ° C. to 7 ° C., which is a temperature setting that is equal to or slightly higher than that of the refrigerator compartment 104. The freezer compartment 106 is set to a freezing temperature zone, and is usually set at −22 ° C. to −15 ° C. for frozen storage, but for example, −30 ° C. or −25 ° C. to improve the frozen storage state. It may be set at a low temperature.

  A lower machine chamber 107 is formed in the rear region of the freezer compartment 106 at the bottom of the heat insulation box 101, and the condenser 108a, an air cooling fan 108b for cooling the condenser 108a, a compressor (not shown), and moisture removal The high-pressure side components of the refrigeration cycle such as a dryer (not shown) for performing the above are accommodated.

  In FIG. 2, a cooling chamber 109 for generating cold air is provided on the back surface of the freezing chamber 106, and a cooling air conveyance air passage to each chamber having heat insulation properties and an insulating partition with each chamber are provided between them. The rear surface partition wall 110 is configured. A cooler 111 is disposed in the cooling chamber 109, and in the upper space of the cooler 111, cold air cooled by the cooler 111 by a forced convection method is blown to the refrigerator compartment 104, the vegetable compartment 105, and the freezer compartment 106. A cooling fan 112 is disposed, and a lower space of the cooler 111 is provided with a radiant heater 113 made of glass tube for defrosting the frost and ice adhering to the cooler 111 and its surroundings at the time of cooling. A drain pan 114 for receiving defrosted water generated at the time of defrosting and draining it outside the storage is configured at the lower part, and an evaporating dish 116 is configured outside the storage on the downstream side. In this embodiment, isobutane, which is a flammable refrigerant, is enclosed in the refrigeration cycle.

  A cool air discharge port 124 for supplying the cool air generated by the cooler 111 to the freezing chamber 106 by the cooling fan 112 and the inside of the freezing chamber 106 are circulated below the cool air discharge port 124 in the rear partition wall 110. A cold air inlet 125 for returning the cold air to the cooler 111 is provided.

  In addition, a storage case is provided in the freezer compartment 106 to be pulled out while being held by a drawer mechanism. In the present embodiment, three storage cases are arranged in the freezer compartment. Specifically, an upper storage case 126, a middle storage case 127, and a lower storage case 128 are arranged.

A door gasket 121 is provided at the inner edge of the heat insulating door 119 over the entire circumference (the door gasket is also provided in the refrigerator compartment 104 and the vegetable compartment 105).
The metal receiving member 123 and the door gasket 121 provided on the front surface of the partition wall 122 having a resin portion on the outer periphery separating 05 and the freezer compartment 106 are closely attached to prevent cold air from leaking to the outside.

  The metal receiving member 123 is provided with a heat radiating pipe 131 so as to be in close contact with the side surface of the metal receiving member 123 in the storage chamber in order to prevent condensation on the outer surface of the storage chamber. The heat radiating pipe 131 uses a high-temperature refrigerant pipe in a refrigeration cycle (not shown), and heats the metal receiving member 123 to a high temperature.

  3 and 4, a convex shape 129 is provided on the surface of the outer box 102 facing the cooling chamber 109 toward the outside air side. Specifically, a convex shape 129 is provided in the width direction of the refrigerator (from the back side to the front side in FIG. 1). Note that the surface of the outer box 102 facing the cooling chamber 109 is an example of the surface of the outer box 102.

  More specifically, the convex shape 129 has a constant interval (equal pitch) on the surface of the outer box 102 facing the cooling chamber 109 with respect to the height direction of the refrigerator 100 (vertical direction in FIG. 3). A plurality of them are provided.

  Moreover, the convex shape 129 is provided continuously in the width direction of the refrigerator.

  In the present embodiment, details of the convex shape are as follows. As shown in FIG. 5, the distance (A dimension) between adjacent convex shapes 129 is 45 mm, the width dimension (B dimension) of the convex shape 129 is 5 mm, the height dimension (D dimension) of the convex shape 129 is 3 mm, and the angle E Is 120 degrees.

  About the refrigerator comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  First, the flow of outside air around the lower machine room 107 will be described.

  Generally, the refrigerator 100 is installed by providing an appropriate space between a wall such as a kitchen and the outer box 102 on the back side. While the inside of the refrigerator 100 is being cooled, the surfaces of the condenser 108a and the compressor become higher than the outside air temperature. In order to improve the heat radiation performance, the air cooling fan 108b cools the condenser 108a and the surface of the compressor. The hot air after the condenser 108a and the compressor surface are air-cooled is exhausted to the back side of the refrigerator 100 as shown by the solid arrows in FIGS. 2 and 3 so that the customer does not feel uncomfortable. The space between the outer box 102 and the outer box 102 flows from the lower machine chamber 107 to the upper side of the refrigerator 100 along the surface of the outer box 102 facing the cooling chamber 109.

  At the same time, the inside of the lower machine room 107 becomes negative pressure by the operation of the air cooling fan 108b, so that the outside air at the bottom of the refrigerator 100 as shown by the broken line arrows in FIGS. A flow is generated by using the space between the floor of the floor and the outer box 102 as an air path.

  Overall, a large flow from the lower part of the heat insulating door 119 to the upper rear of the refrigerator 100 is generated while the inside of the refrigerator 100 is being cooled.

  As described above, when the high-temperature exhaust gas after cooling the condenser 108a and the compressor flows along the surface of the outer box 102 facing the cooling chamber 109, the surface of the outer box 102 facing the cooling chamber 109 is exhausted. It is heated by heat exchange. In particular, since the cooling chamber 109 is provided with the evaporator 111, it is the lowest temperature in the refrigerator 100 and the heat absorption amount is increased.

  Furthermore, when a large amount of products are stored in the refrigerator 100 at a time, for example, when the cooling capacity is suddenly required, the heat dissipation capacity is also required at the same time, so that the condenser 108a and the compressor surface are further heated. At this time, since the rotational speed of the air cooling fan 108b is increased and the condenser 108a and the compressor surface are air-cooled by a large air volume, the exhausted air has a large air volume and a high temperature. growing.

  However, by providing the convex shape 129 so as to be perpendicular to the ascending air current as in the present invention, as shown by the arrow in FIG. 4, it is possible to generate a region where the flow velocity is slow behind the convex shape 129, Since the heat transfer coefficient in the region where the flow velocity is slowed down, the amount of heat absorbed from the surface of the outer box 102 facing the cooling chamber 109 can be suppressed, thereby improving the cooling efficiency and consequently reducing the power consumption. Can be reduced.

  In addition, since the cooling of the cold air can be suppressed, the cold air circulates at a low temperature, so that the temperature distribution in the entire freezer compartment 106 can be kept more uniform.

  Here, details regarding the suppression of the endothermic amount will be described.

  Generally, the amount Q of heat passing is expressed by the following equation.

Q = K * A * Δt K = 1 / (1 / αo + 1 / αi + 1 / λ)
(Q: heat passage amount, A: heat passage area, K: heat passage rate, Δt: temperature difference, αo: outer surface heat transfer rate, αi: storage room surface heat transfer rate, λ: heat insulation wall heat transfer rate ( Combined thermal conductivity of heat insulating material λ1, inner box resin λ2, and outer box steel plate λ3))
As in this embodiment, by providing a convex shape on the surface of the outer box 102 facing the cooling chamber 109 and making the shape of the outer box 102 surface an uneven shape, the flow direction of the updraft on the concave surface immediately after the convex shape As a result, the outer surface heat transfer coefficient αo becomes smaller and K becomes smaller, so that the amount of heat absorption can be suppressed.

  As described above, in the present embodiment, the heat insulating box body 101 includes the inner box 103 and the outer box 102, and the heat insulating box body 101 includes the heat insulating material between the inner box 103 and the outer box 102. A lower machine room 107 formed in the lower part, a condenser 108a installed in the lower machine room 107, an air cooling fan 108b for air-cooling the condenser 108a, and a heat-insulating door 119 for opening and closing the front surface of the opening of the heat-insulating box 101. And a storage chamber 106 having a plurality of different temperature zones formed by the heat insulating box 101 and the heat insulating door 119, and the condenser 108a, which is hotter than the outside air during operation, is air-cooled by the air cooling fan 108b. By providing a convex shape 129 that suppresses heat absorption from high-temperature exhaust gas on the surface of the outer box 102 of the heat insulating box 101 through which the exhaust becomes distributed, the amount of heat absorbed from the surface of the outer box 102 can be reduced. , The 却効 rate is improved, can be provided a refrigerator having reduced power consumption.

  Further, by having a convex shape toward the outside air on the surface of the outer box 102, a region where the flow velocity becomes slow behind the convex shape 129 can be obtained by performing simple processing without performing complicated processing. Since the heat transfer coefficient in the region where the flow rate is slowed down can be generated, the amount of heat absorbed from outside air can be suppressed, thereby improving the cooling efficiency and consequently reducing the power consumption. Can do.

  In addition, by providing a plurality of convex shapes 129 on the same surface of the outer box 102 surface, it is possible to generate more regions where the flow velocity is slower, and to further suppress the amount of heat absorbed from the surface of the outer box 102, thereby improving the cooling efficiency. A refrigerator with improved power consumption can be provided.

Further, since the convex shape 129 is formed integrally with the surface of the outer box 102, no separate parts are required, it is very inexpensive, the number of assembling steps is not increased, and the rigidity strength of the outer box can be improved.

  Further, the convex shape 129 is a part where the condenser 108 a is air-cooled by the air-cooling fan 108 b, and the exhaust gas that has reached a high temperature reaches the surface of the outer box 102 earliest and the cooling chamber 109 has the lowest temperature in the refrigerator 100. By providing it on the surface of the outer box 102 that opposes the heat absorption amount, it is possible to suppress the amount of heat absorption at the portion where the temperature difference occurs most, and the cooling efficiency can be further enhanced.

  Specifically, as shown in FIG. 3, at least a part of the convex shape 129 includes an attachment surface (X portion) of the drain pan 114 provided at the lowermost part in the cooling chamber 109 and an installation position (Y portion) of the radiant heater 113. ).

  That is, the convex shape 129 is provided in the vicinity of the point where the natural convection begins to flow along the outer box 102 almost in parallel.

  Further, even if a convex shape 129 is provided on the surface of the outer box 102 facing the refrigerator compartment 104 in a storage room other than the freezer compartment 106, the same effect can be obtained.

  In the present embodiment, the convex shapes 129 are provided at a constant interval (equal pitch) with respect to the height direction of the outer box 102, but the intervals may be unequal pitches.

  In the present embodiment, the convex shape 129 is provided continuously in the width direction of the refrigerator 100, but is provided intermittently in the width direction of the refrigerator 100 (that is, the width direction of the refrigerator 100). There may be a portion where a convex shape is not provided.

  In this embodiment, the cooling means is cooled by forced convection, but may be cooled by natural convection (so-called direct cooling).

  The convex dimensions shown in this embodiment are examples, and the present invention is not limited to these dimensions.

(Embodiment 2)
FIG. 6 is a lower enlarged sectional view of the refrigerator in the second embodiment of the present invention.

  As shown in FIG. 6, a convex shape 129 is provided on the surface of the outer box 102 at the bottom of the refrigerator 100.

  About the refrigerator comprised as mentioned above, the operation | movement and an effect | action are demonstrated below. In addition, description about the operation | movement and an effect similar to Embodiment 1 is abbreviate | omitted.

  Since the inside of the lower machine room 107 becomes negative pressure by the operation of the air cooling fan 108b, the outside air at the bottom of the refrigerator 100 as shown by the broken line arrow in FIG. 6 is drawn into the lower machine room 107, and the outer box at the bottom of the refrigerator 100 A flow along 102 occurs. By providing the convex shape 129 on the surface of the outer box 102 in a direction perpendicular to the flow, it is possible to generate a region where the flow velocity is slow behind the convex shape 129, and the heat transfer coefficient of the region where the flow velocity is slow is reduced. Therefore, the amount of heat absorption can be suppressed, thereby improving the cooling efficiency and consequently reducing the power consumption.

  In addition, since the cooling of the cold air can be suppressed, the cold air circulates at a low temperature, so that the temperature distribution in the entire freezer compartment 106 can be kept more uniform.

  Further, by having a convex shape toward the outside air on the surface of the outer box 102, a region where the flow velocity becomes slow behind the convex shape 129 can be obtained by performing simple processing without performing complicated processing. Since the heat transfer coefficient in the region where the flow rate is slowed down can be generated, the amount of heat absorbed from outside air can be suppressed, thereby improving the cooling efficiency and consequently reducing the power consumption. Can do.

  In addition, by providing a plurality of convex shapes 129 on the same surface of the outer box 102 surface, it is possible to generate more regions where the flow velocity is slower, and to further suppress the amount of heat absorbed from the surface of the outer box 102, thereby improving the cooling efficiency. A refrigerator with improved power consumption can be provided.

  Further, since the convex shape 129 is formed integrally with the surface of the outer box 102, no separate parts are required, and it is very inexpensive and does not increase the number of assembly steps.

  In addition, the amount of heat absorption can be further suppressed by combining the provision of the convex shape in the outer box 102 shown in the first embodiment and the provision of the convex shape in the outer box 102 shown in the second embodiment. Thus, it is possible to provide a refrigerator with improved cooling efficiency and further reduced power consumption.

  As described above, the refrigerator according to the present invention can be applied to a household or commercial refrigerator or a vegetable storage.

100 Refrigerator 101 Heat insulation box 102 Outer box 103 Inner box 106 Freezer room (storage room)
107 Lower machine room 108a Condenser 108b Air cooling fan 117, 118, 119 Thermal insulation door 129 Convex shape

Claims (3)

An inner box and an outer box, and a heat insulating box provided with a heat insulating material between the inner box and the outer box; a lower machine room formed at a lower portion of the heat insulating box; and A plurality of different temperatures formed by the installed condenser, an air cooling fan for cooling the condenser, a heat insulating door for opening and closing the front surface of the opening of the heat insulating box, and the heat insulating box and the heat insulating door A high temperature exhaust gas on the surface of the outer box of the heat insulation box through which the high temperature exhaust air is circulated by the air cooling fan. The endothermic suppression shape is provided on the outer box bottom surface of the heat insulation box and the outer box surface facing the cooling chamber in which the cooler is disposed . It has a convex shape toward the outside air and is generated by the operation of the air cooling fan in the lower machine room The upper flow and the protruded to be a width direction perpendicular provided that caused by pressure, downstream of the updraft is generated a region where the flow velocity is slowed, reduced heat transfer coefficient refrigerator. The refrigerator according to claim 1, wherein a plurality of the convex shapes are formed on the same surface of the outer box surface of the heat insulating box. The refrigerator according to claim 1 or 2, wherein at least a part of the convex shape is provided on a surface of the outer box facing a storage room having a lowest set temperature in the storage room.