KR20240105349A - Vacuum adiabatic body and refrigerator - Google Patents

Abstract

A vacuum insulator according to one aspect of the present invention includes a first plate member; second plate member; a sealing portion that seals the first plate member and the second plate member to provide a third space, which is a space in a vacuum state; a supporting unit maintaining the third space; a thermal resistance unit for reducing the amount of heat transfer between the first plate member and the second plate member; and an exhaust port for discharging gas in the third space, wherein at least one of the plate members is provided with an extension portion extending toward the third space and coupled to the supporting unit, and the extension portion is at least one of the plate members. It is formed by extending downward from one edge.

Description

Vacuum insulator and refrigerator {Vacuum adiabatic body and refrigerator}

The present invention relates to vacuum insulators and refrigerators.

A vacuum insulator is a product that suppresses heat transfer by maintaining a vacuum inside the body. The vacuum insulator is applied to heating and refrigerating devices because it can reduce heat transfer by convection and conduction. Meanwhile, the insulation method applied to conventional refrigerators varies depending on refrigeration and freezing, but the general method is to provide a foamed polyurethane insulation wall with a thickness of approximately 30 centimeters or more. However, there is a problem that this reduces the internal volume of the refrigerator.

There has been an attempt to apply a vacuum insulator to the refrigerator in order to increase the internal volume of the refrigerator.

First, there is the applicant's registered patent 10-0343719 (Citation 1). According to the registered patent, a vacuum adiabatic panel is manufactured, the vacuum insulating panel is built into the wall of a refrigerator, and the outside of the vacuum insulating panel is finished with a separate molding material such as Styrofoam. According to the above method, there is no need for foaming and the effect of improved insulation performance can be obtained. This method has the problem of increasing costs and complicating the production method. As another example, Patent Publication No. 10-2015-0012712 (Citation Document 2) provides a technology for providing a wall with a vacuum insulating material and, in addition, providing an insulating wall with a foam filler. This method also has the problem of increased cost and complicated manufacturing method.

As another example, there was an attempt to manufacture the walls of a refrigerator entirely from a single piece of vacuum insulator. For example, U.S. Patent Publication US2040226956A1 (Citation Reference 3) discloses providing an insulation structure for a refrigerator in a vacuum state. However, it is difficult to provide a sufficient vacuum to the walls of the refrigerator to achieve a practical level of insulation effect. To explain in detail, it is difficult to prevent heat transfer between the contact area between the outer case and the inner case at different temperatures, it is difficult to maintain a stable vacuum state, it is difficult to prevent deformation of the case due to negative pressure in the vacuum state, etc. There is a problem. Due to these problems, the technology in Reference 3 is limited to cryogenic refrigeration devices and does not provide technology at a level that can be applied in general homes.

Registered Patent 10-0343719 Figure 7 of Publication Patent No. 10-2015-0012712 US Patent Publication US2040226956A1

The present invention is proposed against the background described above, and proposes a vacuum insulator and refrigerator that obtain sufficient insulation effect by vacuum and can be applied commercially.

In addition, a structure for improving the bearing capacity of the plate member provided in the vacuum insulator is proposed.

In order to solve the above problems, the vacuum insulator according to one aspect of the present invention includes a first plate member; second plate member; a sealing portion that seals the first plate member and the second plate member to provide a third space, which is a space in a vacuum state; a supporting unit maintaining the third space; a thermal resistance unit for reducing the amount of heat transfer between the first plate member and the second plate member; and an exhaust port for discharging gas in the third space, wherein at least one of the plate members is provided with an extension portion extending toward the third space and coupled to the supporting unit, and the extension portion is at least one of the plate members. It is formed by extending downward from one edge.

In order to solve the above problems, a vacuum insulator according to another aspect of the present invention includes a first plate member; second plate member; a sealing portion that seals the first plate member and the second plate member to provide a third space, which is a space in a vacuum state; a supporting unit maintaining the third space; a thermal resistance unit for reducing the amount of heat transfer between the first plate member and the second plate member; and an exhaust port for discharging gas in the third space, the heat resistance unit is connected to at least one of the plate members, and a conduction port for reducing the amount of heat transfer between the first plate member and the second plate member. A resistance sheet is included, and at least one of the plate members is provided with an extension portion that extends toward the third space and is coupled to the supporting unit.

In order to solve the above problems, a refrigerator according to one aspect of the present invention includes a main body; and a door, and to supply refrigerant to the main body, a compressor; condenser; expander; and an evaporator, wherein at least one of the main body and the door includes a vacuum insulator, the vacuum insulator including a first plate member; second plate member; a sealing part that seals the first plate member and the second plate member to provide a vacuum space; A supporting unit maintaining the vacuum space portion; heat resistance unit; and an exhaust port for discharging gas from the vacuum space, and at least one of the plate members is provided with an extension portion that extends toward the third space and is coupled to the supporting unit.

The vacuum insulation effect according to the present invention can be obtained.

Additionally, the supporting force of the plate member can be improved by using a supporting unit.

1 is a perspective view of a refrigerator according to an embodiment.
Figure 2 is a diagram schematically showing a vacuum insulator used in the main body and door of a refrigerator.
Figure 3 is a diagram showing various embodiments of the internal configuration of the vacuum space portion.
Figure 4 is a diagram showing various embodiments of a conductive resistance sheet and its peripheral portion.
Figure 5 is a graph showing the change in insulation performance and gas conductivity according to vacuum pressure by applying simulation.
Figure 6 is a graph observing the process of exhausting the inside of the vacuum insulator in terms of time and pressure when the supporting unit is used.
Figure 7 is a graph comparing vacuum pressure and gas conductivity.
FIG. 8 is a diagram illustrating the mutual relationship between the supporting unit and the first plate member and shows a portion of an edge.
Figure 9 is an enlarged view of Figure 8.
Figure 10 is a longitudinal cross-sectional view of Figure 8.
Figure 11 is a diagram showing a supporting unit and a radiation resistance sheet.
Figure 12 is a plan view of Figure 11.
Figure 13 is a diagram showing a vacuum insulator according to another embodiment.
FIG. 14 is a view showing the first plate member of FIG. 13.
Figure 15 is a diagram showing a vacuum insulator according to another embodiment.
Figure 16 is a diagram showing a vacuum insulator according to another embodiment.
Figure 17 is a longitudinal cross-sectional view of Figure 16.

Below, specific embodiments of the present invention are proposed with reference to the drawings. However, the spirit of the present invention is not limited to the embodiments presented below, and those skilled in the art who understand the spirit of the present invention can add, change, delete, and add components to other embodiments included within the scope of the same spirit. It can be easily proposed by, etc., but it will also be said to be included within the scope of the idea of the present invention.

The drawings presented below may be different from the actual product, exaggerated, simple or detailed parts may be deleted, but this is for the convenience of understanding the technical idea of the present invention, and the size, structure and shape shown in the drawings are It should not be construed as limited.

In the following description, vacuum pressure means any pressure condition lower than atmospheric pressure. And, the expression that A has a higher vacuum level than B means that the vacuum pressure of A is lower than that of B.

1 is a perspective view of a refrigerator according to an embodiment.

Referring to FIG. 1, the refrigerator 1 includes a main body 2 provided with a cavity 9 for storing items, and a door 3 provided to open and close the main body 2. The door 3 is arranged to be rotatable or slide to open and close the cavity 9. The cavity 9 may provide at least one of a refrigerator compartment and a freezer compartment.

Components forming a refrigeration cycle that supplies cold air to the cavity are provided. In detail, a compressor (4) that compresses the refrigerant, a condenser (5) that condenses the compressed refrigerant, an expander (6) that expands the condensed refrigerant, and an evaporator (7) that evaporates the expanded refrigerant and takes away heat. ) is included. As a typical structure, a fan may be installed at a location adjacent to the evaporator 7, and fluid blown from the fan may be allowed to pass through the evaporator 7 and then be blown into the cavity 9. The refrigeration load can be controlled by adjusting the amount and direction of blowing air by the fan, controlling the amount of circulating refrigerant, or adjusting the compression ratio of the compressor, thereby controlling the refrigerating space or freezing space.

Figure 2 is a diagram schematically showing the vacuum insulator used in the main body and door of the refrigerator. The main body side vacuum insulator is shown with the top and side walls removed, and the door side vacuum insulator is a part of the front wall. This is a drawing with the removed. In addition, the cross-section of the portion where the conduction resistance sheets 60 and 63 are provided is schematically shown to facilitate understanding.

Referring to FIG. 2, the vacuum insulator includes a first plate member 10 providing a wall of a low-temperature space, a second plate member 20 providing a wall of a high-temperature space, and the first plate member 10. ) and a vacuum space 50 defined as a gap between the second plate member 20 is included. Conduction resistance sheets 60 and 63 that prevent heat conduction between the first and second plate members 10 and 20 are included. In order to keep the vacuum space 50 in a sealed state, a sealing portion 61 is provided to seal the first plate member 10 and the second plate member 20. When the vacuum insulator is applied to a refrigerator or refrigerator, the first plate member 10 may be referred to as an inner case, and the second plate member 20 may be referred to as an outer case. At the lower rear of the vacuum insulator on the main body, a machine room (8) is placed where parts that provide a refrigeration cycle are stored, and on one side of the vacuum insulator, air in the vacuum space (50) is exhausted to create a vacuum state. An exhaust port 40 is provided for. Additionally, a pipe 64 penetrating the vacuum space 50 may be further installed to install defrost water and electric lines.

The first plate member 10 may define at least a portion of the wall for the first space provided on the first plate member side. The second plate member 20 may define at least a portion of the wall for the second space provided on the second plate member side. The first space and the second space may be defined as spaces having different temperatures. Here, the wall for each space not only functions as a wall that directly contacts the space, but also may function as a wall that does not contact the space. For example, the vacuum insulator of the embodiment can be applied even to an article that has a separate wall in contact with each space.

Factors that cause the vacuum insulator to lose its insulation effect include heat conduction between the first plate member 10 and the second plate member 20, heat radiation between the first plate member 10 and the second plate member 20, and gas conduction of the vacuum space portion 50.

Below, a thermal resistance unit provided to reduce insulation loss in relation to the above heat transfer factors will be described. Meanwhile, the vacuum insulator and the refrigerator of the embodiment are not excluded from having another insulating means on at least one side of the vacuum insulator. Accordingly, the other surface may further have an insulating means using foam or the like.

Figure 3 is a diagram showing various embodiments of the internal configuration of the vacuum space portion.

First, referring to FIG. 3A, the vacuum space 50 is provided as a third space at a pressure different from the first space and the second space, preferably in a vacuum state, thereby reducing insulation loss. The third space may be provided at a temperature that is between the temperature of the first space and the temperature of the second space. Since the third space is provided as a space in a vacuum state, the first plate member 10 and the second plate member 20 contract in a direction approaching each other by a force equal to the pressure difference between each space. Because it receives the vacuum space portion 50, it can be deformed in a direction that makes it smaller. In this case, insulation loss may occur due to an increase in the amount of radiation transfer due to contraction of the vacuum space portion and an increase in the amount of conduction transfer due to contact with the plate members 10 and 20.

A supporting unit 30 may be provided to reduce deformation of the vacuum space portion 50. The supporting unit 30 includes a bar 31. The bar 31 may extend in a direction substantially perpendicular to the plate member to support the gap between the first plate member and the second plate member. A support plate 35 may be additionally provided on at least one end of the bar 31. The support plate 35 connects at least two bars 31 and may extend in a horizontal direction with respect to the first and second plate members 10 and 20. The support plate may be provided in a plate shape, or may be provided in a grid shape to reduce the area in contact with the first and second plate members 10 and 20, thereby reducing heat transfer. The bar 31 and the support plate can be fixed at least in one part and inserted together between the first and second plate members 10 and 20. The support plate 35 may contact at least one of the first and second plate members 10 and 20 to prevent the first and second plate members 10 and 20 from being deformed. In addition, based on the direction in which the bar 31 extends, the total cross-sectional area of the support plate 35 is provided to be larger than the total cross-sectional area of the bar 31, so that the heat transmitted through the bar 31 is reduced. It may spread through the support plate 35.

Materials of the supporting unit 30 include PC, glass fiber PC, and low outgassing PC to obtain high compressive strength, low outgassing and water absorption, low thermal conductivity, high compressive strength at high temperatures, and excellent processability. A resin selected from , PPS, and LCP can be used.

A radiation resistance sheet 32 that reduces heat radiation between the first and second plate members 10 and 20 through the vacuum space 50 will be described. The first and second plate members 10 and 20 may be made of stainless steel, which can prevent corrosion and provide sufficient strength. Since the stainless steel material has a relatively high emissivity of 0.16, a lot of radiant heat transfer can occur. In addition, the emissivity of the supporting unit made of resin is lower than that of the plate member, and since it is not provided entirely on the inner surfaces of the first and second plate members 10 and 20, it does not have a significant effect on radiant heat. Therefore, in order to focus on reducing radiant heat transfer between the first plate member 10 and the second plate member 20, the radiation resistance sheet is provided in a plate shape across most of the area of the vacuum space portion 50. It can be. As the material of the radiation resistance sheet 32, a product with a low emissivity is preferable, and in the embodiment, an aluminum sheet with an emissivity of 0.02 can be preferably used. Additionally, since a single radiation resistance sheet cannot provide a sufficient radiant heat blocking effect, at least two radiation resistance sheets 32 may be provided at regular intervals so as not to contact each other. Additionally, at least one radiation resistance sheet may be provided in contact with the inner surfaces of the first and second plate members 10 and 20.

Referring to FIG. 3B, the gap between the plate members can be maintained by the supporting unit 30, and the inside of the vacuum space 50 can be filled with the porous material 33. The porous material 33 may have a higher emissivity than stainless steel, which is the material of the first and second plate members 10 and 20, but since it fills the vacuum space, the resistance efficiency of radiant heat transfer is high.

In the case of this embodiment, there is an effect of manufacturing a vacuum insulator without the radiation resistance sheet 32.

Referring to FIG. 3C, the supporting unit 30 that maintains the vacuum space portion 50 is not provided. Instead, the porous material 33 was provided wrapped in a film 34. At this time, the porous material 33 may be provided in a compressed state so as to maintain the gap in the vacuum space. The film 34 may be made of PE material and may be provided with holes.

In the case of this embodiment, the vacuum insulator can be manufactured without the supporting unit 30. In other words, the porous material 33 can perform both the function of the radiation resistance sheet 32 and the function of the supporting unit 30.

Figure 4 is a diagram showing various embodiments of a conductive resistance sheet and its peripheral portion. Although the structure of each conductive resistance sheet is simply shown in Figure 2, it can be understood in more detail through this drawing.

First, the conduction resistance sheet shown in Figure 4a can be preferably applied to the main body side vacuum insulator. In detail, the second plate member 20 and the first plate member 10 must be sealed to maintain the interior of the vacuum insulator in a vacuum. At this time, since the two plate members each have different temperatures, heat transfer may occur between them. A conduction resistance sheet 60 is provided to prevent heat conduction between two different types of plate members.

The conduction resistance sheet 60 defines at least a portion of the wall for the third space and may be provided as a sealing portion 61 at both ends of which are sealed to maintain a vacuum state. The conduction resistance sheet 60 is provided as a micrometer-scale thin plate to reduce the amount of heat conduction flowing along the wall of the third space. The sealing portion 61 may be provided as a welded portion. That is, the conduction resistance sheet 60 and the plate members 10 and 20 can be fused to each other. In order to achieve a fusion effect between the conductive resistance sheets 60 and the plate members 10 and 20, the same material may be used, and stainless steel may be used as the material. The sealing portion 61 is not limited to a welding portion and may be provided through a method such as caulking. The conduction resistance sheet 60 may be provided in a curved shape. Accordingly, the heat conduction distance of the conduction resistance sheet 60 is provided to be longer than the straight line distance of each plate member, and the amount of heat conduction can be further reduced.

A temperature change occurs along the conduction resistance sheet 60. Therefore, in order to block heat transfer to the outside, it is preferable that a shielding portion 62 is provided on the outside of the conductive resistance sheet 60 to achieve an insulating effect. In other words, in the case of a refrigerator, the second plate member 20 is at a high temperature and the first plate member 10 is at a low temperature. In addition, the conduction resistance sheet 60 conducts heat from high temperature to low temperature, and the temperature of the sheet changes rapidly along the heat flow. Therefore, when the conduction resistance sheet 60 is open to the outside, heat transfer through the open portion may occur severely. In order to reduce this heat loss, a shielding portion 62 is provided on the outside of the conduction resistance sheet 60. For example, even when the conduction resistance sheet 60 is exposed to either a low-temperature space or a high-temperature space, the conduction resistance sheet 60 does not perform the role of conduction resistance to the amount exposed, which is undesirable. do.

The shielding portion 62 may be provided as a porous material in contact with the outer surface of the conduction resistance sheet 60, or may be provided as an insulating structure exemplified by a separate gasket placed on the outside of the conduction resistance sheet 60. , the main body side vacuum insulator may be provided as a part of the vacuum insulator provided at a position facing the corresponding conduction resistance sheet 60 when the door side vacuum insulator is closed. In order to reduce heat loss even when the main body and the door are opened, the shielding portion 62 may preferably be made of a porous material or a separate insulating structure.

The conduction resistance sheet shown in Figure 4b can be preferably applied to the door side vacuum insulator, and the parts that differ from Figure 4a will be explained in detail, and the same explanation will be applied to the same parts. A side frame 70 is further provided outside the conduction resistance sheet 60. The side frame 70 may be equipped with parts for sealing the door and the main body, exhaust ports required for the exhaust process, and getter ports for maintaining vacuum. This is because, although it may be convenient to install parts in the case of a vacuum insulator on the main body, the location on the door side is limited.

In the case of a door-side vacuum insulator, it is difficult for the conduction resistance sheet 60 to be placed on the front end of the vacuum space, that is, on the side edge of the corner. This is because the corner edge of the door 3 is exposed to the outside, unlike the main body. In more detail, when the conduction resistance sheet 60 is placed at the front end of the vacuum space, the corner edge of the door 3 is exposed to the outside, so a separate insulation part must be formed to insulate the conduction resistance sheet 60. Because there is a disadvantage.

The conduction resistance sheet shown in FIG. 4C can be preferably installed in a pipe penetrating a vacuum space, and the different parts with respect to FIGS. 4A and 4B will be described in detail, and the same explanation will be applied to the same parts. The peripheral portion where the conduit 64 is provided may be provided in the same shape as in FIG. 4A, and more preferably, a corrugated conduction resistance sheet 63 may be provided. According to this, the heat transfer path can be lengthened and deformation due to pressure difference can be prevented. Additionally, a separate shielding portion may be provided for insulation of the conduction resistance sheet.

Referring again to FIG. 4A, the heat transfer path between the first plate member 10 and the second plate member 20 will be described. The heat passing through the vacuum insulator includes surface conduction heat (①) transmitted along the surface of the vacuum insulator, more specifically the conduction resistance sheet 60, and the supporting unit (30) provided inside the vacuum insulator. ) can be divided into supporter conduction heat (②) conducted along the vacuum space, gas conduction heat (③) through the internal gas of the vacuum space, and radiative transfer heat (④) transmitted through the vacuum space.

The heat transfer may be modified according to various design values. For example, the supporting unit may be changed so that the first and second plate members 10 and 20 can withstand vacuum pressure without being deformed, the vacuum pressure may be changed, and the spacing length of the plate members may be varied, The length of the conduction resistance sheet can be changed and can vary depending on the temperature difference between each space (first space and second space) provided by the plate member. In the case of the example, a preferable configuration was found considering that the total heat transfer amount is smaller than that of the conventional insulation structure provided by foaming polyurethane. Here, the actual heat transfer coefficient in a refrigerator foaming conventional polyurethane can be presented as 19.6mW/mK.

If the heat transfer amount of the vacuum insulator of the embodiment according to this is relatively analyzed, heat transfer by gas conduction heat (③) can be minimized. For example, this can be controlled to less than 4% of the total heat transfer. Heat transfer by solid conduction heat, defined as the sum of the surface conduction heat (①) and the supporter conduction heat (②), is the most common. For example, it could reach 75%. The radiation transfer heat (③) is smaller than the solid conduction heat, but is larger than the heat transfer by gas conduction heat. For example, the radiation transfer heat (③) may account for approximately 20% of the total heat transfer amount.

According to this heat transfer distribution, the effective heat transfer coefficient (eK: effective K) (W/mK) can have the order of Equation 1 when comparing the transfer heat (①②③④).

Here, the actual heat transfer coefficient (eK) is a value that can be measured using the shape and temperature difference of the target article, and is a value that can be obtained by measuring the total amount of heat transfer and the temperature of at least one part where heat is transferred. For example, by placing a quantitatively measurable heating source in the refrigerator, the heat generation amount is known (W), and the temperature distribution of the door is measured (K) to measure the heat transmitted through the door body and the door rim of the refrigerator, respectively. By confirming the path as a converted value (m), the actual heat transfer coefficient can be obtained.

The actual heat transfer coefficient (eK) of the entire vacuum insulator is a value given by k=QL/A△T, where Q is the heat transfer amount (W) and can be obtained using the calorific value of the heater, and A is the amount of heat transfer (W) of the vacuum insulator. is the cross-sectional area (m ² ), L is the thickness of the vacuum insulator (m), and △T can be defined as the temperature difference.

The surface conduction heat is the temperature difference (△T) of the inlet and outlet of the conduction resistance sheet (60) (63), the cross-sectional area of the conduction resistance sheet (A), the length of the conduction resistance sheet (L), and the thermal conductivity (k) of the conduction resistance sheet ( The amount of conduction heat can be determined through (the thermal conductivity of the conduction resistance sheet can be determined in advance as a physical property of the material). The supporter conduction heat can be determined through the temperature difference (△T) of the inlet and outlet of the supporting unit 30, the cross-sectional area of the supporting unit (A), the length of the supporting unit (L), and the thermal conductivity (k) of the supporting unit. . Here, the thermal conductivity of the supporting unit can be determined in advance as a physical property of the material. The sum of the gas conduction heat (③) and the radiation transfer heat (④) can be found by subtracting the surface conduction heat and the supporter conduction heat from the heat transfer amount of the entire vacuum insulator. The ratio of the gas conduction heat and the radiation transfer heat can be found by determining the radiation transfer heat when the vacuum degree of the vacuum space is significantly lowered so that there is no gas conduction heat.

When a porous material is provided inside the vacuum space 50, the porous material conduction heat (⑤) can be considered as the sum of the supporter conduction heat (②) and the radiant heat (④). The porous material conduction heat can be changed by various variables such as the type and amount of the porous material.

According to the embodiment, it is preferable that the temperature difference (△T ₁ ) between the geometric centers formed by the adjacent bars 31 and the place where the bars are located is less than 0.5 degrees Celsius. In addition, it can be preferably proposed that the temperature difference (△T ₂ ) between the geometric center formed by the adjacent bar and the edge portion of the vacuum insulator is provided to be less than 5 degrees Celsius. In addition, in the second plate member, at the point where the heat transfer path passing through the conduction resistance sheets 60 and 63 meets the second plate member, the temperature difference with the average temperature of the second plate member may be the largest. there is. For example, when the second space is a hotter area than the first space, the temperature becomes lowest at the point of the second plate member where the heat transfer path passing through the conduction resistance sheet meets the second plate member. Similarly, when the second space is a cold area compared to the first space, the temperature becomes highest at the point of the second plate member where the heat transfer path passing through the conduction resistance sheet meets the second plate member.

This means that the amount of heat transfer through other sources other than the surface conduction heat passing through the conduction resistance sheet must be sufficiently controlled, and only when the surface conduction heat accounts for the largest amount of heat transfer can the total heat transfer amount that satisfies the vacuum insulator as a whole be achieved. It means getting an advantage. To this end, the temperature change amount of the conduction resistance sheet can be controlled to be greater than the temperature change amount of the plate member.

The physical characteristics of each component providing the vacuum insulator will be described. In the vacuum insulator, force due to vacuum pressure is applied to all parts. Therefore, it is desirable to use a material having a certain level of strength (N/m ² ).

Under this background, it is preferable that the plate members 10 and 20 and the side frame 70 are made of a material that has sufficient strength not to break even under vacuum pressure. For example, if the number of bars 31 is reduced to limit supporter conduction heat, deformation of the plate member may occur due to vacuum pressure, which may adversely affect the appearance. The radiation resistance sheet 32 is preferably a product that has a low emissivity and can be easily processed into a thin film, and must be strong enough not to be deformed by external shock. The supporting unit 30 must be strong enough to support the force generated by vacuum pressure and withstand external shock, and must be workable. The conduction resistance sheet 60 is preferably made of a material that is thin and can withstand vacuum pressure.

In an embodiment, the plate member, side frame, and conduction resistance sheet may be made of stainless steel with the same strength. The radiation resistance sheet may be made of aluminum, which has a weaker strength than stainless steel. The supporting unit may be made of resin, which has a weaker strength than aluminum.

Unlike the strength viewed in terms of material as mentioned above, analysis in terms of rigidity is required. The stiffness (N/m) is a property that is not easily deformed, and even if the same material is used, the stiffness may vary depending on the shape. The conduction resistance sheets 60 and 63 may be made of a strong material, but it is preferable that they have low rigidity in order to increase thermal resistance and spread evenly without rough surfaces when vacuum pressure is applied to minimize radiant heat. The radiation resistance sheet 32 is required to have a certain level of rigidity to prevent it from touching other parts due to deformation. In particular, the edge portion of the radiation resistance sheet may sag due to its own weight, thereby generating conductive heat. Therefore, a certain level of rigidity is required. The supporting unit 30 requires a level of rigidity that can withstand compressive stress from the plate member and external shock.

In the embodiment, it is preferable that the plate member and the side frame have the highest rigidity to prevent deformation due to vacuum pressure. The supporting unit, especially the bar, preferably has the second highest rigidity. The radiation resistance sheet is weaker than the supporting unit, but is preferably stronger than the conduction resistance sheet. Lastly, it is desirable that the conduction resistance sheet be easily deformed by vacuum pressure, so it is desirable to use a material with the lowest rigidity.

Even when the inside of the vacuum space 50 is filled with the porous material 33, it is desirable for the conduction resistance sheet to have the lowest rigidity, and it is desirable for the plate member and the side frame to have the highest rigidity.

Below, the vacuum pressure that is preferably presented depending on the internal state of the vacuum insulator will be described. As already explained, the interior of the vacuum insulator must maintain vacuum pressure to reduce heat transfer. In this case, it can be easily expected that maintaining a vacuum pressure as low as possible is desirable to reduce heat transfer.

The vacuum space portion may resist heat transfer only by the supporting unit 30, or the inside of the vacuum space portion 50 may be filled with a porous material 33 together with the supporting unit to resist heat transfer, and the supporting unit may be Without applying it, it is possible to resist heat transfer with porous materials.

A case in which only a supporting unit is provided will be described.

Figure 5 is a graph showing the change in insulation performance and gas conductivity according to vacuum pressure by applying simulation.

Referring to Figure 5, as the vacuum pressure decreases, that is, as the vacuum degree increases, the thermal load in the case of the body alone (Graph 1) or the body and door combined (Graph 2) is compared to a conventional polyurethane foamed product. As a result, it can be seen that the heat load is reduced and the insulation performance is improved. However, it can be seen that the degree of improvement in insulation performance gradually decreases. In addition, it can be seen that as the vacuum pressure decreases, the gas conductivity (Graph 3) decreases. However, it can be seen that even as the vacuum pressure decreases, the rate of improvement in insulation performance and gas conductivity gradually decreases. Therefore, it is desirable to lower the vacuum pressure as much as possible, but obtaining excessive vacuum pressure requires a lot of time and is expensive due to excessive use of getters. In the examples, the optimal vacuum pressure is proposed from the above viewpoint.

Figure 6 is a graph observing the process of exhausting the inside of the vacuum insulator in terms of time and pressure when the supporting unit is used.

Referring to FIG. 6, in order to create the vacuum space 50 in a vacuum state, the gas in the vacuum space is exhausted using a vacuum pump while heating (baking) to vaporize any potential gas remaining in the components of the vacuum space. However, when the vacuum pressure reaches a certain level, a point is reached where the level of vacuum pressure no longer increases (△t ₁ ). Afterwards, disconnect the vacuum space part of the vacuum pump and apply heat to activate the getter (△t ₂ ). When the getter is activated, the pressure in the vacuum space drops for a certain period of time, but then normalizes and maintains a certain level of vacuum pressure. The vacuum pressure when maintaining a certain level of vacuum pressure after activation of the getter is approximately 1.8×10 ^-6 Torr.

In the embodiment, the point at which the vacuum pressure no longer substantially decreases even when the vacuum pump is operated to exhaust the gas is set as the lower limit of the vacuum pressure used in the vacuum insulator, and the lowest internal pressure of the vacuum space is set to 1.8 × 10 ^-6 Torr. Set to .

Figure 7 is a graph comparing vacuum pressure and gas conductivity.

Referring to FIG. 7, gas conductivity according to vacuum pressure according to the size of the gap within the vacuum space 50 is shown as a graph of the actual heat transfer coefficient (eK). The gap of the vacuum space was measured in three cases: 2.76mm, 6.5mm, and 12.5mm. The gap in the vacuum space is defined as follows. If the radiation resistance sheet 32 is inside the vacuum space, it is the distance between the radiation resistance sheet and the adjacent plate, and if there is no radiation resistance sheet inside the vacuum space, it is the distance between the first plate member and the second plate member. 2 This is the distance between plate members.

The point corresponding to the conventional actual heat transfer coefficient of 0.0196 W/mk, which provides insulation by foaming polyurethane, was found to be 2.65 × 10 ^-1 Torr even when the gap size was 2.76 mm due to the small gap size. Meanwhile, even if the vacuum pressure was lowered, it was confirmed that the point where the reduction effect of the insulation effect due to gas conduction heat was saturated was approximately 4.5 × 10 ^-3 Torr. The pressure of 4.5×10 ^-3 Torr can be determined as the point where the effect of reducing gas conduction heat is saturated. Additionally, when the actual heat transfer coefficient is 0.1 W/mk, it is 1.2×10 ^-2 Torr.

When the supporting unit is not provided in the vacuum space and the porous material is provided, the gap size ranges from several micrometers to hundreds of micrometers. In this case, due to the porous material, radiant heat transfer is small even when the vacuum pressure is relatively high, that is, even when the vacuum degree is low. Therefore, use an appropriate vacuum pump suitable for the vacuum pressure. The appropriate vacuum pressure for the corresponding vacuum pump is approximately 2.0×10 ^-4 Torr. Additionally, the vacuum pressure at the point where the reduction effect of gas conduction heat is saturated is approximately 4.7×10 ^-2 Torr. In addition, the pressure at which the gas conduction heat reduction effect reaches the conventional real heat transfer coefficient of 0.0196 W/mk is 730 Torr.

When the supporting unit and the porous material are provided together in the vacuum space, a vacuum pressure between the cases of using only the supporting unit and the porous material can be created and used.

The vacuum insulator presented in the present invention is preferably applied to refrigerators. However, the application of vacuum insulators is not limited to refrigerators, and can be applied to various places such as ultra-low temperature refrigeration devices, warming devices, and blowing devices.

Hereinafter, a vacuum insulator according to another embodiment of the present invention will be described.

FIG. 8 is a diagram illustrating the relationship between the supporting unit and the first plate member and shows an edge portion, and FIG. 9 is an enlarged view of FIG. 8.

Referring to Figures 8 and 9, the vacuum insulator according to an embodiment of the present invention includes a first plate member 110 that provides a wall of a low-temperature space, and a second plate member 120 that provides a wall of a high-temperature space. ) and a vacuum space 150 defined as the gap between the first plate member 10 and the second plate member 20, and a supporting unit 130 for reducing deformation of the vacuum space 150. Includes.

The supporting unit 130 includes a plurality of bars 131 interposed between the first plate member 110 and the second plate member 120, and a first bar provided at one end of the plurality of bars 131. It may include a support plate 135 and a second support plate 136 provided at the other end of the plurality of bars 131.

The pitch between the plurality of bars 131 may be narrower in a portion adjacent to the edge of the first plate member 110 or the edge of the second plate member 120 than in the remaining portion. This is because the supporting force of the edge portions of the first plate member 110 and the second plate member 120 is weaker than that of other portions.

The first support plate 135 may be placed in contact with the first plate member 110, and the second support plate 136 may be placed in contact with the second plate member 120.

The first and second support plates 135 and 136 may each be provided in a grid shape, and thus the area in contact with the first and second plate members 10 and 20 is reduced, thereby reducing the amount of heat transfer. .

An extension portion 112 may be formed on the first plate member 110 to strengthen the support force with the supporting unit 130. The extension portion 112 may be formed to extend downward from the end of the first plate member 110.

Fixing portions 137 and 138 may be formed on the second support plate 136.

At least a portion of the fixing parts 137 and 138 may be in contact with the extension part 112.

The extension portion 112 may be provided in plural numbers, and the fixing portions 137 and 138 may be formed to correspond to each extension portion 112.

The fixing parts 137 and 138 may include a first fixing part 137 that contacts one surface of the extension part 112.

The first fixing part 137 may be formed to extend upward from the second support plate 136. Meanwhile, in the drawing, the first fixing part 137 is disposed on the outside of the extension part 112, but differently, the first fixing part 137 may be provided on the inside of the extension part 112.

The fixing parts 137 and 138 may include a second fixing part 138 surrounding the extension part 112.

The second fixing part 138 may be formed to extend upward from the second support plate 136. A groove into which the extension portion 112 is inserted may be formed in the second support plate 136. Accordingly, the extension part 112 can be combined with the second fixing part 138.

As shown, the first fixing parts 137 are arranged in a row on one side of the second support plate 136, and the second fixing parts 138 are arranged on the other side of the second support plate 136. Can be arranged in a row. However, it is not limited to this arrangement.

Figure 10 is a longitudinal cross-sectional view of Figure 8.

Referring to Figure 10, the vacuum insulator of the present invention is provided with a conduction resistance sheet 160 to prevent heat conduction between the first plate member 110 and the second plate member 120.

The conduction resistance sheet 160 defines at least a portion of the wall for the third space and may be provided as a sealing portion 161 whose both ends are sealed to maintain a vacuum state. The conduction resistance sheet 160 is provided as a micrometer-scale thin plate to reduce the amount of heat conduction flowing along the wall of the third space.

A side frame 170 may be provided outside the conduction resistance sheet 160.

One side of the conduction resistance sheet 160 may be fastened to the first plate member 110, and the other side of the conduction resistance sheet 160 may be fastened to the side frame 170.

A plurality of bars may be interposed between the side frame 170 and the second plate member 120 to maintain the gap between the side frame 170 and the second plate member 120.

Among the plurality of bars 131 interposed between the first plate member 110 and the second plate member 120, a bar is disposed at the outermost position between the side frame 170 and the second plate member 120. The shortest distance between the plurality of bars interposed is shorter than the pitch between the plurality of bars 131 interposed between the first plate member 110 and the second plate member 120. This is to prevent deformation of the side frame 170.

A welding portion 161 for sealing may be formed on the conduction resistance sheet 160. Specifically, both sides of the conduction resistance sheet 161 may be welded after being seated on the first plate member 110 and the side frame 170, respectively.

FIG. 11 is a diagram showing a supporting unit and a radiation resistance sheet, and FIG. 12 is a plan view of FIG. 11.

Referring to FIGS. 11 and 12, the supporting unit 130 may be seated on the second plate member 120, and the supporting unit 130 includes a plurality of radiation resistance sheets 132, 133, and 134. may be provided.

The plurality of radiation resistance sheets 132, 133, and 134 may be penetrated by a plurality of bars 131. Each radiation resistance sheet 132, 133, and 134 may be arranged to be spaced apart by a separate spacer.

The second support plate 136 is provided with a first fixing part 137 and a second fixing part 138 that protrude upward.

It is effective to improve thermal insulation performance when the plurality of radiation resistance sheets 132, 133, and 134 are disposed over the widest possible range within the vacuum space portion 150. However, when the first fixing part 137 and the second fixing part 138 come into contact with the plurality of radiation resistance sheets 132, 133, and 134, the insulation performance may be reduced due to heat transfer.

Therefore, the first fixing part 137 and the second fixing part 138 must be arranged so as not to contact the plurality of radiation resistance sheets 132, 133, and 134.

Accordingly, a recessed portion 132a in which the first fixing portion 137 can be accommodated is formed in the first radiation resistance sheet 132. A depression 132b in which the second fixing part 138 can be accommodated is formed in the first radiation resistance sheet 132. Accordingly, the first fixing part 137 and the second fixing part 138 may not be in contact with the first radiation resistance sheet 132.

A depression in which the first fixing part 137 and the second fixing part 138 are accommodated may be formed in the second radiation resistance sheet 133 and the third radiation resistance sheet 134.

FIG. 13 is a view showing a vacuum insulator according to another embodiment, and FIG. 14 is a view showing the first plate member of FIG. 13.

Referring to Figures 13 and 14, unlike the previous embodiment, the vacuum insulator of this embodiment is not provided with a fixing part, and there is a difference in the shape of the extension part.

The vacuum insulator of this embodiment includes a first plate member 210 and a second plate member 220, a first support plate 235 is in contact with the first plate member 210, and the second plate The second support plate 236 is in contact with the member 220. At least one bar 231 may be interposed between the first support plate 235 and the second support plate 236.

At least one radiation resistance sheet 232 may be provided between the first support plate 235 and the second support plate 236. The radiation resistance sheet 232 may be penetrated by the at least one bar 231.

The first plate member 210 may be provided with an extension portion 212 extending downward. The extension portion 212 may be provided in plural numbers.

The extension portion 212 may be in contact with the side surface of the first support plate 235, and as the plurality of extension portions 212 are provided, the first plate member 210 may be connected to the first support plate ( 235). The first support plate 235 can be viewed as being fitted into the first plate member 210.

The lower end of the extension part 212 may be located above the radiation resistance sheet 232 so that the extension part 212 and the radiation resistance sheet 232 do not contact.

The extension portion 212 may be formed integrally with the first plate member 210, but is not limited to this, and the extension portion 212 and the first plate member 210 may be formed separately from each other. It can be provided in the configuration of.

Figure 15 is a diagram showing a vacuum insulator according to another embodiment.

Referring to FIG. 15, the vacuum insulator of this embodiment differs from the vacuum insulator of the previous embodiment only in the shape of the extension portion.

Specifically, the vacuum insulator of this embodiment includes an extension portion 312 extending downward from the edge portion of the first plate member 310. A first support plate 335 is in contact with the lower end of the first plate member 310, and the extension portion 312 may be provided to contact the first support plate 335.

The extension portion 312 may be provided to extend downward from the entire edge portion of the first plate member 310. That is, the extension portion 312 may be formed to be longer than the extension portion 212 of the previous embodiment. In this case, only one extension portion 312 is provided at one corner of the first plate member 310.

The extension portion 312 may be formed integrally with the first plate member 310, but is not limited to this, and the extension portion 312 and the first plate member 310 may be formed separately from each other. It can be provided in the configuration of.

The extension portion 312 may extend downward within a length range that does not contact the radiation resistance sheet.

Accordingly, the first plate member 310 can be supported by being fixed to the first support plate 335.

Figure 16 is a diagram showing a vacuum insulator according to another embodiment, and Figure 17 is a longitudinal cross-sectional view of Figure 16.

Referring to Figures 16 and 17, the vacuum insulator of this embodiment may be formed so that the extension portion protrudes downward from the surface of the plate member rather than the edge portion.

The vacuum insulator of this embodiment includes a first plate member 410, a first support plate 435 in contact with the lower side of the first plate member 410, and at least one bar supporting the first support plate 435. (431) is included. The at least one bar 431 may be provided between the second support plates 436.

An extension portion 412 protruding toward the first support plate 435 may be formed on the first plate member 410 .

Unlike the extension part of the previous embodiment, the extension part 412 is formed to protrude downward from a certain point of the plate rather than the edge of the first plate member 410.

The extension portion 412 may be formed on the first plate member 410 of a planar shape through a forming mold.

The extension portion 412 may be formed to protrude into a shape corresponding to the groove provided in the first support plate 435. Accordingly, the extension part 412 can be fitted into the groove provided in the first support plate 435.

Accordingly, the first support plate 435 can be supported by being fixed to the first support plate 435 .

Meanwhile, in the present invention, the first plate member is fixed to the supporting unit, but a structure in which the second plate member is fixed to the supporting unit instead of the first plate member is also possible.

The above description is merely an illustrative explanation of the technical idea of the present invention, and various modifications and variations will be possible to those skilled in the art without departing from the essential characteristics of the present invention. Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but are for illustrative purposes, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted in accordance with the claims below, and all technical ideas within the equivalent scope should be construed as being included in the scope of rights of the present invention.

The present invention allows vacuum insulators to be applied industrially to various insulation facilities. By increasing the insulation effect, energy use efficiency can be increased and the effective volume of equipment can be increased, so urgent industrial application is actively expected.

Claims (20)

first plate member;
second plate member;
a vacuum space portion provided between the first plate member and the second plate member and forming a space in a vacuum state; and
It includes a supporting unit that maintains the vacuum space portion,
The vacuum space portion has a thickness in a first direction, and the supporting unit includes a bar extending in the first direction,
The supporting unit is a vacuum insulator including a fixing portion provided to be spaced apart from the bar while extending in the first direction or extending in a direction approaching the center of the vacuum space portion.
According to paragraph 1,
The fixing part includes a part provided with a different length from the bar, or
The fixing part includes a part having a length different from the thickness of the vacuum space part, or
A vacuum insulator in which a plurality of bars are provided, and the fixing part is provided between the plurality of bars.
According to claim 1,
The fixing part is provided with a length shorter than the bar, or
The fixing part is a vacuum insulator provided with a length shorter than the thickness of the vacuum space part.
According to paragraph 1,
At least one of the first plate member and the second plate member includes an extension portion extending in the first direction,
The fixing part includes a part provided to contact or support one surface of the extension part, or
The fixing part includes a part provided to surround the extension part, or
The fixing part is a vacuum insulator including a part disposed inside or outside the extension part.
According to paragraph 4,
A vacuum insulator wherein a plurality of extension parts are provided, and the fixing part corresponds to each extension part.
According to paragraph 4,
The fixing part is a vacuum insulator including a first fixing part in contact with one surface of the extension part and a second fixing part surrounding the extension part.
According to paragraph 1,
The bars are provided with at least two,
The supporting unit is a vacuum insulator including a support plate connecting the at least two bars to each other so that the at least two bars can be positioned together next to the first plate member.
In clause 7,
The support plate is a vacuum insulator extending in a first direction of the vacuum space portion to support the gap between two adjacent bars.
According to paragraph 1,
The fixing part is a vacuum insulator that contacts one side of the first plate member.
first plate member;
second plate member;
a vacuum space portion provided between the first plate member and the second plate member and forming a space in a vacuum state; and
It includes a supporting unit that maintains the vacuum space portion,
The vacuum space portion has a thickness in a first direction,
The supporting unit includes a portion extending in the first direction,
At least one of the first plate member and the second plate member includes an extension portion extending in the first direction.
According to clause 10,
At least one of the first plate member and the second plate member further includes a portion extending from the extension portion in a direction different from the first direction.
According to clause 10,
It includes a supporting unit that maintains the vacuum space portion,
The vacuum space portion has a thickness in a first direction, and the supporting unit includes a bar extending in the first direction and a support plate connecting the bar and extending in a horizontal direction with respect to at least one of the plate members. sifter
According to clause 12,
The extension portion is in contact with the support plate and supports the structure of the support plate and the first plate member.
According to clause 12,
The extension portion is a vacuum insulator in contact with the bar.
first plate member;
second plate member;
a vacuum space portion provided between the first plate member and the second plate member and forming a space in a vacuum state; and
It includes a supporting unit that maintains the vacuum space portion,
The supporting unit includes a support plate contacting at least one of the first and second plate members,
A vacuum insulator wherein the support plate is provided with a fixing part extending in one direction.
According to clause 15,
The fixing part includes a part provided with a different length from the support plate, or
The fixing part includes a part having a length different from the thickness of the vacuum space part, or
A vacuum insulator wherein a plurality of fixing parts are provided, and the plurality of fixing parts are spaced apart from each other.
According to clause 15,
The fixing part is provided to have a protruding height longer than the thickness of the support plate, or
The fixing part is a vacuum insulator provided with a length shorter than the thickness of the vacuum space part.
According to clause 15,
At least one of the first plate member and the second plate member includes an extension portion extending in the first direction,
The fixing part includes a part provided to contact or support one surface of the extension part, or
The fixing part includes a part provided to surround the extension part, or
The fixing part is a vacuum insulator including a part disposed inside the extension part or outside the extension part.
According to clause 18,
A vacuum insulator wherein a plurality of extension parts are provided, and the fixing part corresponds to each extension part.
According to clause 18,
The fixing part is a vacuum insulator including a first fixing part in contact with one surface of the extension part and a second fixing part surrounding the extension part.