KR20220079506A - Vacuum adiabatic body and refrigerator - Google Patents

Abstract

A vacuum insulator according to an aspect of the present invention includes a first plate member; a second plate member; a sealing part sealing the first plate member and the second plate member to provide a third space that is a space in a vacuum state; a supporting unit for maintaining the third space; a heat resistance unit for reducing an amount of heat transfer between the first plate member and the second plate member; and an exhaust port for discharging the gas of the third space, wherein the supporting unit includes a support plate in contact with the first plate member and the second plate member, respectively, wherein the plate member and the support plate are each It is made of a curved surface, and the greater the distance from the center of curvature, the greater the curvature is formed.

Description

Vacuum insulator and refrigerator {Vacuum adiabatic body and refrigerator}

The present invention relates to a vacuum insulator and a refrigerator.

A vacuum insulator is an article that suppresses heat transfer by maintaining a vacuum inside the body. Since the vacuum insulator can reduce heat transfer by convection and conduction, it is being applied to a heating device and a refrigeration device. On the other hand, although there is a difference according to refrigeration and freezing in the insulation method applied to the conventional refrigerator, it was a general method to provide a foamed polyurethane insulation wall having a thickness of about 30 cm or more. However, there is a problem in that the internal volume of the refrigerator is reduced by this.

There is 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 (cited document 1). According to the registered patent, a vacuum adiabatic panel is manufactured, the vacuum insulation panel is built into the wall of the refrigerator, and the outside of the vacuum insulation panel is finished with a separate molding made of Styrofoam. According to the above method, there is no need for foaming, and the effect of improving the thermal insulation performance can be obtained. This method has problems in that the cost increases and the manufacturing method becomes complicated. As another example, Korean Patent Application Laid-Open No. 10-2015-0012712 (Citation Document 2) discloses a technique for providing a wall with a vacuum insulating material and providing an insulating wall with a foam filler in addition thereto. This method also has problems in that the cost increases and the manufacturing method is complicated.

As another example, there was an attempt to manufacture the wall of the refrigerator as a single product, a vacuum insulator. For example, US Patent Publication No. US2040226956A1 (Cited Document 3) discloses providing an insulating structure of a refrigerator in a vacuum state. However, it is difficult to obtain a practical level of insulation effect by providing the wall of the refrigerator in a sufficient vacuum state. In detail, it is difficult to prevent the heat transfer phenomenon between the contact part of the outer case and the inner case having different temperatures, it is difficult to maintain a stable vacuum state, and it is difficult to prevent deformation of the case due to the negative pressure of the vacuum state, etc. There is a problem of Due to these problems, the technology of Citation 3 is also limited to cryogenic refrigeration equipment, and it does not provide a level of technology that can be applied at home.

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

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

In addition, a vacuum insulator at least a portion of which forms a curved surface and a refrigerator including the same are proposed.

In order to solve the above problems, the vacuum insulator according to an aspect of the present invention includes a first plate member; a second plate member; a sealing part sealing the first plate member and the second plate member to provide a third space that is a space in a vacuum state; a supporting unit for maintaining the third space; a heat resistance unit for reducing an amount of heat transfer between the first plate member and the second plate member; and an exhaust port for discharging the gas of the third space, wherein the supporting unit includes a support plate in contact with the first plate member and the second plate member, respectively, wherein the plate member and the support plate are each It is made of a curved surface, and the greater the distance from the center of curvature, the greater the curvature is formed.

In order to solve the above problems, the vacuum insulator according to another aspect of the present invention includes a first plate member; a second plate member; a sealing part sealing the first plate member and the second plate member to provide a third space that is a space in a vacuum state; a supporting unit for maintaining the third space; a heat resistance unit for reducing an amount of heat transfer between the first plate member and the second plate member; and an exhaust port for discharging the gas of the third space, wherein the supporting unit includes a support plate in contact with the first plate member and the second plate member, respectively, wherein the plate member and the support plate are each made of curved surfaces.

In order to solve the above problems, a refrigerator according to an aspect of the present invention includes a main body; and a door, comprising: a compressor; condenser; inflator; and an evaporator, wherein at least one of the main body and the door includes a vacuum insulator, and the vacuum insulator includes: a first plate member; a second plate member; a sealing part sealing the first plate member and the second plate member to provide a vacuum space part; a supporting unit for maintaining the vacuum space; heat resistance unit; and an exhaust port for discharging the gas of the vacuum space, wherein the supporting unit includes a plurality of bars interposed between the first plate member and the second plate member; a support plate in contact with the first plate member and the second plate member, respectively, and connected to upper ends and lower ends of the plurality of bars; and a radiation resistance sheet provided in a plate shape inside the third space and penetrated by the plurality of bars, wherein the first plate member, the second plate member, and the support plate each have curved surfaces.

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

In addition, it is possible to manufacture a curved vacuum insulator by changing only the assembly process without injecting the components constituting the vacuum insulator into a curved surface.

1 is a perspective view of a refrigerator according to an embodiment.
2 is a diagram schematically illustrating a vacuum insulator used for a main body and a door of a refrigerator.
3 is a view showing various embodiments of the internal configuration of the vacuum space part.
4 is a view showing various embodiments of a conductive resistance sheet and its peripheral portion.
5 is a graph showing a change in thermal insulation performance and a change in gas conductivity according to vacuum pressure by applying a simulation.
6 is a graph for observing the process of evacuating the inside of the vacuum insulator with time and pressure when the supporting unit is used.
7 is a graph comparing vacuum pressure and gas conductivity.
8 is a view showing a vacuum insulator having a curved shape.
9 is a view showing a supporting unit.
10 is an exploded view of a supporting unit;
11 is an exploded view of a supporting unit provided with a plurality of radiation resistance sheets.
12 is a view of the supporting unit as viewed from above.
13 is a view showing a side surface of a supporting unit;
14 is a view showing an edge portion of a support plate.

Hereinafter, 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 may add, change, delete, and add components to other embodiments included within the scope of the same spirit. It will be easily suggested by, etc., but this will also be included within the scope of the spirit of the present invention.

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

In the following description, vacuum pressure means any pressure state lower than atmospheric pressure. And, the expression that A has a higher degree of vacuum 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 , a refrigerator 1 includes a main body 2 provided with a cavity 9 for storing stored items, and a door 3 provided to open and close the main body 2 . The door 3 may be rotatably arranged or slidably arranged to open and close the cavity 9 . The cavity 9 may provide at least one of a refrigerating compartment and a freezing compartment.

A component constituting a refrigeration cycle for supplying cold air to the cavity is provided. Specifically, a compressor 4 for compressing the refrigerant, a condenser 5 for condensing the compressed refrigerant, an expander 6 for expanding the condensed refrigerant, and an evaporator 7 for evaporating the expanded refrigerant to take heat ) is included. As a typical structure, a fan may be installed at a position adjacent to the evaporator 7 , and the fluid blown from the fan may be blown into the cavity 9 after passing through the evaporator 7 . By adjusting the blowing amount and blowing direction by the fan, adjusting the amount of the circulating refrigerant, or adjusting the compression rate of the compressor, the refrigeration load may be adjusted, thereby controlling the refrigerated space or the refrigerated space.

2 is a view schematically showing a vacuum insulator used for the main body and door of the refrigerator. The vacuum insulator on the main body side is shown with the upper and side walls removed, and the vacuum insulator on the door side is a part of the front wall. It is a drawing of the state in which is removed. In addition, the cross-section of the portion where the conductive resistance sheets 60 and 63 are provided is schematically shown to facilitate understanding.

Referring to FIG. 2 , in the vacuum insulator, 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 portion 50 defined as a space between the second plate member 20 and the second plate member 20 is included. Conduction resistance sheets 60 and 63 for preventing heat conduction between the first and second plate members 10 and 20 are included. A sealing part 61 for sealing the first plate member 10 and the second plate member 20 is provided in order to seal the vacuum space part 50 . When the vacuum insulator is applied to a refrigerator or a 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. A machine room 8 is placed on the lower rear side of the vacuum insulator on the main body side, in which parts providing a refrigeration cycle are accommodated. An exhaust port 40 is provided for In addition, a conduit 64 passing through the vacuum space 50 may be further installed for the installation of defrost water and electric lines.

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

Factors causing the loss of the thermal insulation effect of the vacuum insulator include heat conduction between the first plate member 10 and the second plate member 20 and heat radiation between the first plate member 10 and the second plate member 20, and gas conduction of the vacuum space part 50 .

Hereinafter, a heat resistance unit provided to reduce adiabatic loss in relation to the factor of heat transfer will be described. On the other hand, the vacuum insulator and the refrigerator of the embodiment do not exclude further having another heat insulating means on at least one side of the vacuum insulator. Accordingly, it may further have a heat insulating means using foam or the like on the other surface.

3 is a view showing various embodiments of the internal configuration of the vacuum space part.

First, referring to FIG. 3A , the vacuum space unit 50 is provided as a third space at a pressure different from that of 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 corresponding to between the temperature of the first space and the temperature of the second space. Since the third space is provided as a vacuum space, 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 in each space. Since it receives the vacuum space portion 50 may be deformed in a smaller direction. In this case, an increase in the amount of radiation transmission due to the contraction of the vacuum space portion and an increase in the amount of conduction transmission due to the contact of the plate members 10 and 20 may cause thermal insulation loss.

A supporting unit 30 may be provided to reduce deformation of the vacuum space 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 a gap between the first plate member and the second plate member. A support plate 35 may be additionally provided at at least one end of the bar 31 . The support plate 35 may connect at least two or more bars 31 and 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, and may be provided in a grid shape so that an area in contact with the first and second plate members 10 and 20 is reduced to reduce heat transfer. The bar 31 and the support plate may be fixed in at least one portion 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 deformation of the first and second plate members 10 and 20 . In addition, based on the extension direction of the bar 31 , the total cross-sectional area of the support plate 35 is larger than the total cross-sectional area of the bar 31 , so that the heat transferred through the bar 31 is It may be diffused through the support plate 35 .

As a material of the supporting unit 30, in order to obtain high compressive strength, low outgassing and water absorption, low thermal conductivity, high compressive strength at high temperature, and excellent workability, PC, glass fiber PC, low outgassing PC , PPS, and a resin selected from LCP may 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 a stainless material capable of preventing corrosion and providing sufficient strength. Since the stainless material has a relatively high emissivity of 0.16, a lot of radiant heat transfer may 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 entirely provided on the inner surfaces of the first and second plate members 10 and 20, it does not significantly affect radiant heat. Therefore, the radiation resistance sheet is provided in a plate shape across most of the area of the vacuum space part 50 in order to focus on the reduction of radiant heat transfer between the first plate member 10 and the second plate member 20 . can be As a material of the radiation-resisting sheet 32, an article having a low emissivity is preferable, and in an embodiment, an aluminum thin plate having an emissivity of 0.02 may be preferably used. In addition, since it is not possible to obtain a sufficient radiation heat shielding action with one sheet of radiation resistance, at least two sheets of radiation resistance sheet 32 may be provided at a predetermined interval so as not to contact each other. In addition, at least one radiation resistance sheet may be provided in a state in contact with the inner surfaces of the first and second plate members 10 and 20 .

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

In the case of this embodiment, there is an effect that the vacuum insulator can be manufactured without the radiation resistance sheet 32 .

Referring to FIG. 3C , the supporting unit 30 for maintaining the vacuum space part 50 is not provided. Instead of this, the porous material 33 was provided in a state wrapped in the film 34 . At this time, the porous material 33 may be provided in a compressed state so as to maintain a gap between the vacuum space portions. The film 34 may be provided in a state in which a hole is punched, for example, of a PE material.

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

4 is a view showing various embodiments of a conductive resistance sheet and its peripheral portion. Although the structure of each conductive resistance sheet is simply illustrated in FIG. 2 , it will be understood in more detail through this drawing.

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

The conductive resistance sheet 60 may be provided as a sealing part 61 that defines at least a part of a wall for the third space and is sealed at both ends to maintain a vacuum state. The conductive resistance sheet 60 is provided as a micrometer thin plate to reduce the amount of heat conduction flowing along the wall of the third space. The sealing part 610 may be provided as a welding part. That is, the conductive resistance sheet 60 and the plate members 10 and 20 may be fused to each other. In order to induce a fusion action between each other, the conductive resistance sheet 60 and the plate members 10 and 20 may use the same material, and stainless steel may be used as the material. The sealing part 610 is not limited to a welding part and may be provided through a method such as caulking. The conductive resistance sheet 60 may be provided in a curved shape. Accordingly, the distance of heat conduction of the conductive resistance sheet 60 is provided longer than the linear distance of each plate member, so that the amount of heat conduction can be further reduced.

A temperature change occurs along the conductive resistance sheet 60 . Therefore, in order to block the heat transfer with the outside, it is preferable that the shielding part 62 is provided on the outside of the conductive resistance sheet 60 so that the heat insulating action occurs. 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. And, in the conductive resistance sheet 60, heat conduction occurs from a high temperature to a low temperature, and the temperature of the sheet changes abruptly along the heat flow. Therefore, when the conductive resistance sheet 60 is opened to the outside, heat transfer through the open place may occur severely. In order to reduce such heat loss, a shielding part 62 is provided on the outside of the conductive resistance sheet 60 . For example, even when the conductive resistance sheet 60 is exposed to either a low temperature space or a high temperature space, the conductive resistance sheet 60 does not perform the role of conductive resistance as much as the exposed amount, which is undesirable. do.

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

The conductive resistance sheet shown in FIG. 4B can be preferably applied to the door-side vacuum insulator, and the different parts will be described in detail with respect to FIG. 4A, and the same description will be applied to the same parts. A side frame 70 is further provided outside the conductive resistance sheet 60 . The side frame 70 may include parts for sealing the door and the body, an exhaust port necessary for an exhaust process, and a getter port for maintaining a vacuum. This is because, in the case of the vacuum insulator on the body side, the installation of parts may be convenient, but the position of the door side is limited.

In the case of a door-side vacuum insulator, it is difficult for the conductive resistance sheet 60 to be placed on the front end of the vacuum space, that is, on the side of the corner. This is because the corner edge portion of the door 3 is exposed to the outside unlike the body. In more detail, when the conductive resistance sheet 60 is placed on the front end of the vacuum space part, the corner edge portion of the door 3 is exposed to the outside. Because there are disadvantages.

The conductive resistance sheet shown in FIG. 4C may be preferably installed in a pipe passing through the vacuum space, and different parts will be described in detail with respect to FIGS. 4A and 4B, and the same description 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 conductive resistance sheet 63 may be provided. According to this, the heat transfer path can be lengthened and deformation due to the pressure difference can be prevented. In addition, a separate shield for insulation of the conductive resistance sheet may be provided.

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

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

Accordingly, if the heat transfer amount of the vacuum insulator of the embodiment is relatively analyzed, heat transfer by the gas conduction heat (③) can be made the smallest. For example, this can be controlled to less than 4% of the total heat transfer. Heat transfer by solid conduction heat, which is defined as the sum of the surface conduction heat (①) and the supporter conduction heat (②), is the most. For example, it can reach 75%. The radiation transfer heat (③) is smaller than the solid conduction heat, but 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) may have the order of Equation 1 when comparing the heat transfer heat (①②③④).

Here, the real 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 portion through which heat is transferred. For example, place a quantitatively measurable heating source in the refrigerator to know the amount of heat generated (W), measure the temperature distribution of the door for heat transmitted through the door body of the refrigerator and the edge of the door, respectively (K), and heat transfer The actual heat transfer coefficient can be obtained by confirming the path to be converted as a converted value (m).

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

The surface conduction heat is, the temperature difference (ΔT) at the entrance and exit of the conductive resistance sheet 60 and 63, the cross-sectional area of the conductive resistance sheet (A), the length of the conductive resistance sheet (L), and the thermal conductivity of the conductive resistance sheet (k) ( The thermal conductivity of the conductive resistance sheet can be found out in advance as the physical properties of the material) to find out the amount of conduction heat. The supporter conduction heat is the temperature difference (ΔT) at the entrance and exit 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 of the supporting unit (k). . Here, the thermal conductivity of the supporting unit can be found in advance as a physical property value 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 to the radiative transfer heat can be found out by finding the radiant 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 unit 50, the porous material conduction heat (⑤) can be considered as the sum of the supporter conduction heat (②) and radiant heat (④). The heat of conduction of the porous material may be changed by various variables such as the type and amount of the porous material.

According to the embodiment, the temperature difference (ΔT ₁ ) between the geometric center of the bars 31 adjacent to each other and the location where the bars are positioned is preferably provided to be less than 0.5°C. In addition, the temperature difference (ΔT ₂ ) between the geometric center formed by the adjacent bars and the edge portion of the vacuum insulator may preferably be provided to be less than 5 degrees Celsius. In addition, in the second plate member, at a 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 greatest. have. For example, when the second space is a hotter region than the first space, the temperature is the lowest at the point of the second plate member where the heat transfer path passing through the conductive resistance sheet meets the second plate member. Similarly, when the second space is a region that is colder than the first space, the temperature becomes the highest at the point of the second plate member where the heat transfer path passing through the conductive resistance sheet meets the second plate member.

This means that the amount of heat transfer through other places except for the surface conduction heat passing through the conduction resistance sheet must be sufficiently controlled, and only when surface conduction heat occupies the largest heat transfer amount, it is possible to achieve the total amount of heat transfer satisfied by the vacuum insulator as a whole. It means getting an advantage. To this end, the temperature change amount of the conductive resistance sheet may be controlled to be greater than the temperature change amount of the plate member.

Physical characteristics of each component providing the vacuum insulator will be described. In the vacuum insulator, force by vacuum pressure is applied to all parts. Therefore, it is preferable 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 having sufficient strength not to be damaged despite vacuum pressure. For example, when the number of bars 31 is reduced to limit supporter conduction heat, deformation of the plate member by vacuum pressure may occur, which may adversely affect the appearance. The radiation-resisting sheet 32 is preferably an article that has a low emissivity and can be easily processed into a thin film, and must have a degree of strength that is not deformed by external impact. The supporting unit 30 must be provided with strength to support the force by vacuum pressure and withstand external impact, and have workability. The conductive resistance sheet 60 is preferably made of a thin plate-like material that can withstand vacuum pressure.

In an embodiment, the plate member, the side frame, and the conduction resistance sheet may use a stainless material having the same strength. The radiation resistance sheet may be made of aluminum having a weaker strength than stainless steel. The supporting unit may use a resin having a weaker strength than aluminum as its material.

Unlike the strength seen in terms of the material as described above, an 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 thereof. The conductive resistance sheets 60 and 63 may be made of a material having high strength, but it is preferable to increase the thermal resistance and to spread evenly without a rough surface when vacuum pressure is applied to minimize the radiated heat. The radiation resistance sheet 32 is required to have a certain level of rigidity in order not to touch other parts due to deformation. In particular, the edge portion of the radiation resistance sheet may sag according to its own weight to generate conductive heat. Therefore, a certain level of rigidity is required. The supporting unit 30 is required to be rigid enough to withstand the compressive stress and external impact from the plate member.

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. Preferably, the supporting unit, particularly the bar, has the second greatest stiffness. The radiation resistance sheet is weaker than the supporting unit, but it is preferable to have rigidity than the conductive resistance sheet. Lastly, it is preferable that the conductive resistance sheet be easily deformed by vacuum pressure, so it is preferable 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 preferable that the conductive resistance sheet have the lowest rigidity, and it is preferable that the plate member and the side frame have the highest rigidity.

Hereinafter, a vacuum pressure preferably suggested according to the internal state of the vacuum insulator will be described. As already described, the inside of the vacuum insulator must maintain a vacuum pressure to reduce heat transfer. In this case, it can be easily predicted that it is desirable to maintain a vacuum pressure as low as possible to reduce heat transfer.

The vacuum space may resist heat transfer only by the supporting unit 30, and the porous material 33 may be filled with the supporting unit in the vacuum space 50 to resist heat transfer, and the supporting unit may be It is also possible to resist heat transfer with a porous material without application.

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

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

5, the lower the vacuum pressure, that is, the higher the degree of vacuum, the higher the heat load in the case of only the body (graph 1) or when the body and the door are combined (graph 2), compared with the conventional polyurethane foamed article Therefore, 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 the thermal insulation performance is gradually lowered. In addition, it can be seen that the lower the vacuum pressure, the lower the gas conductivity (graph 3). However, it can be seen that even if the vacuum pressure is lowered, the rate at which the thermal insulation performance and gas conductivity are improved gradually decreases. Therefore, although it is desirable to lower the vacuum pressure as much as possible, there are problems in that it takes a lot of time to obtain an excessive vacuum pressure, and costs are high due to the use of an excessive getter. The embodiment proposes an optimal vacuum pressure from the above point of view.

6 is a graph for observing the process of evacuating the inside of the vacuum insulator with time and pressure when the supporting unit is used.

Referring to FIG. 6 , in order to form the vacuum space part 50 in a vacuum state, while heating (baking), the potential gas remaining in the vacuum space part parts is vaporized and the gas of the vacuum space part is exhausted by a vacuum pump. However, when the vacuum pressure exceeds a certain level, it reaches a point where the level of the vacuum pressure no longer increases (Δt ₁ ). After that, the connection of the vacuum space of the vacuum pump is disconnected and heat is applied to activate the getter (Δt ₂ ). When the getter is activated, the pressure in the vacuum space decreases for a certain period of time, but it is normalized and the vacuum pressure is maintained at a certain level. When the vacuum pressure is maintained at a certain level after activation of the getter, the vacuum pressure is approximately 1.8×10 ^-6 Torr.

In the embodiment, the point at which the vacuum pressure is no longer substantially lowered even if the gas is exhausted by operating the vacuum pump is set as the lower limit of the vacuum pressure used in the vacuum insulator, so that the lowest internal pressure of the vacuum space is 1.8×10 ^-6 Torr set to

7 is a graph comparing vacuum pressure and gas conductivity.

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

The point corresponding to the conventional real heat transfer coefficient 0.0196 W/mk for providing an insulating material by foaming polyurethane was found to be 2.65×10 ⁻¹ Torr even when the size of the gap was 2.76 mm due to the small size of the gap. On the other hand, even if the vacuum pressure is lowered, it was confirmed that the point at which the reduction effect of the insulation effect due to the gas conduction heat is saturated is approximately 4.5×10 ^-3 Torr. The pressure of 4.5×10 ^-3 Torr can be determined as a point at which the effect of reducing the gas conduction heat is saturated. Also, when the real 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 size of the gap ranges from several micrometers to several hundreds of micrometers. In this case, even when the vacuum pressure is relatively high due to the porous material, that is, even when the degree of vacuum is low, radiant heat transfer is small. Therefore, an appropriate vacuum pump suitable for the vacuum pressure is used. The appropriate vacuum pressure for the corresponding vacuum pump is approximately 2.0×10 ^-4 Torr. In addition, the vacuum pressure at the point where the effect of reducing the gas conduction heat is saturated is approximately 4.7×10 ^-2 Torr. In addition, the pressure at which the reduction effect of gas conduction heat 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 intermediate between the case of using only the supporting unit and the case of using only the porous material may be created and used.

8 is a view showing a vacuum insulator having a curved shape.

Referring to FIG. 8 , the vacuum insulator of the present invention includes a first plate member 110 , a second plate member 120 , a first support plate 135 , a second support plate 136 , and at least one bar ( 131) and a radiation resistance sheet 132.

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

Here, the first plate member 110 , the second plate member 120 , the first support plate 135 , the second support plate 136 , and the radiation resistance sheet 132 are each curved. and each member has a larger curvature value as the distance from the center of curvature increases.

9 is a view showing a supporting unit, and FIG. 10 is an exploded view of the supporting unit.

9 and 10 , the supporting unit includes a first support plate 135 , a second support plate 136 , and a plurality of bars 131 .

The supporting unit has a structure in which the plurality of bars 131 are fixed to the second support plate 136 , and the first support plate 135 is detachably attached to the other end of the plurality of bars 131 . can Accordingly, the combination of the second support plate 136 and the plurality of bars 131 may be referred to as a “base” and the first support plate 135 may be referred to as a “cover”.

A plurality of insertion portions 137 into which respective bars 131 are inserted may be provided in the first support plate 135 . A pitch between the plurality of insertion portions 137 has a smaller value than a pitch between the plurality of bars 131 attached to the second support plate 136 .

The distance R1 from the center of curvature to the first support plate 135, the distance R2 to the radiation resistance sheet 132, and the distance R3 to the second plate member 136 are sequentially increases

The pitches P1 , P2 , and P3 between the plurality of bars 131 may also be formed to increase as the distance from the center of curvature increases. Here, P1 means a pitch between the plurality of insertion parts 137 provided in the first support plate 135 , P2 means a pitch between through holes provided in the radiation resistance sheet 132 , and P3 is It means a pitch at a point where the second support plate 136 and the plurality of bars 131 are connected.

11 is an exploded view of a supporting unit provided with a plurality of radiation resistance sheets.

Referring to FIG. 11 , a plurality of radiation resistance sheets 132 , 133 , and 134 may be provided between the first support plate 135 and the second support plate 136 . The first radiation resistance sheet 132 , the second radiation resistance sheet 133 , and the third radiation resistance sheet 134 may be sequentially disposed in a direction away from the center of curvature.

A plurality of through holes 132a, 133a, and 134a through which the respective bars 131 pass may be formed in each of the radiation resistance sheets 132 , 133 , and 134 .

The pitch between the plurality of through-holes 132a, 133a, and 134a provided in each may increase as the distance from the center of curvature increases.

In addition, the ends of the plurality of radiation resistance sheets 132 , 133 , and 134 may be provided to become longer as the distance from the center of curvature increases. This can be seen in the same context as the pitch between the plurality of through-holes 132a, 133a, and 134a increases.

FIG. 12 is a view of the supporting unit looking down from above, FIG. 13 is a view showing a side surface of the supporting unit, and FIG. 14 is a view showing an edge portion of the support plate.

12 to 14 , the second support plate 136 includes a plurality of connection ribs 136a and 136b forming a grid shape.

The plurality of connection ribs 136a and 136b include a plurality of first connection ribs 136a extending in a horizontal direction and a plurality of second connection ribs 136b extending in a vertical direction in the drawing.

The plurality of first connection ribs 136a are formed to extend along the circumferential direction of the second support plate 136 forming a curved surface, and the plurality of second connection ribs 136b may form the curved second support plate 136 . The plate 136 is formed to extend along the central axis of curvature.

That is, each of the plurality of first connecting ribs 136a is bent to form a curve, and each of the plurality of second connecting ribs 136b forms a straight line.

Each of the first connection ribs 136a may be thinner than each of the second connection ribs 136b. This is so that each of the first connecting ribs 136a is well bent to form a curve. In this case, each of the second connection ribs 136b may serve to reinforce strength by being thickly formed on each of the first connection ribs 136a.

For example, each of the first connecting ribs 136a may have a thickness of 1 mm or more and 3 mm or less.

A plurality of first connection ribs and a plurality of second connection ribs may be provided on the first support plate 135 like the second support plate 136 .

Each bar 131 may be provided at a point where the first connection rib 136a and the second connection rib 136b meet.

A plurality of connecting portions 138 may be formed at a portion where each of the bars 131 and the second support plate 136 are connected. A pitch between the plurality of connection parts 138 may be greater than a pitch between the plurality of insertion parts 137 . This is because the plurality of connecting portions 138 are disposed farther from the center of curvature than the plurality of insertion portions 137 .

However, when the connection part 138 is provided on the first support plate 135 and the insertion part 137 is provided on the second support plate 136 , a pitch between the plurality of connection parts 138 is provided. may be formed to be smaller than the pitch between the plurality of insertion parts 137 . In this case, this is because the plurality of connecting portions 138 are disposed closer to the center of curvature than the plurality of insertion portions 137 .

Each of the plurality of connecting portions 138 may be formed to be rounded. Accordingly, damage due to shear when processing or assembling the second support plate 136 may be reduced. The round dimension R may be of approximately 0.05 mm to 1 mm.

The third connecting rib 139 formed on the edge of the second supporting plate 136 is thicker than the first connecting rib 136a and the second connecting rib 136b. For example, the third connecting rib 139 may be formed to be thicker than the first connecting rib 136a and the second connecting rib 136b by 0.2 mm.

In addition, the third connection rib 139 may be made of a material having a higher density than that of the first connection rib 136a and the second connection rib 136b. This is to compensate for the fact that the edge portion of the second support plate 136 may be weak in the strength portion. Accordingly, damage to the second support plate 136 may be prevented.

The vacuum insulator presented in the present invention is preferably applied to a refrigerator. However, the application of the vacuum insulator is not limited to the refrigerator, and may be applied to various places such as a cryogenic refrigeration device, a heating device, and a blower device.

The present invention enables the vacuum insulator to be industrially applied to various thermal insulation facilities. It is possible to increase the energy use efficiency by increasing the thermal insulation effect and increase the effective capacity of the equipment, so urgent industrial application is actively expected.

Claims (23)

a first plate member having a first temperature;
a second plate member having a second temperature different from the first temperature;
a vacuum space portion provided between the first plate member and the second plate member; and
and a supporting unit that maintains a distance between the first plate member and the second plate member, and is provided adjacent to the first plate member or next to the first plate member,
The supporting unit includes a support plate extending in the longitudinal direction of the vacuum space,
At least one of the first plate member and the second plate and the support plate each have a curved surface,
The support plate is
a plurality of first connecting ribs extending along the circumferential direction of the support plate and bent to form a curve and spaced apart from each other; and
A vacuum insulator comprising a plurality of second connecting ribs extending along the central axis of curvature of the support plate, extending in a direction crossing the extending direction of the first connecting ribs, and spaced apart from each other. The method of claim 1,
The first and second connecting ribs are vacuum insulators forming a grid shape with each other. The method of claim 1,
The first connecting rib is a vacuum insulator formed thinner than the second connecting rib. The method of claim 1,
The first connecting rib has a thickness of 1 mm or more and 3 mm or less. According to claim 1,
The vacuum insulator further comprising a third connection rib respectively connected to both ends of the first connection rib and the second connection rib to form an edge. 6. The method of claim 5,
The support plate is
The third connecting rib is a vacuum insulator formed thicker than each of the first and second connecting ribs. 6. The method of claim 5,
The third connecting rib is a vacuum insulator made of a material having a higher density than that of each of the first and second connecting ribs. The method of claim 1,
A vacuum insulator comprising a plurality of bars interposed between the first plate member and the second plate member and connected to the support plate. 9. The method of claim 8,
It further comprises a third connection rib connected to both ends of the first connection rib and the second connection rib, respectively, forming an edge,
The plurality of bars,
an intersection of the first connecting rib and the second connecting rib;
an intersection of the first connecting rib and the third connecting rib;
Vacuum insulators respectively disposed at intersections of the second connecting ribs and the third connecting ribs. The method of claim 1,
and a heat resistance unit for reducing an amount of heat transfer between the first plate member and the second plate member. 11. The method of claim 10,
The heat resistance unit includes a radiation resistance sheet provided in the form of a plate in the space of the vacuum state and penetrated by the plurality of bars,
The radiation resistance sheet is a vacuum insulator forming a curved surface. 12. The method of claim 11,
The radiation resistance sheet is provided in plurality and is spaced apart from each other,
A vacuum insulator in which a plurality of through holes through which each bar passes are formed in each radiation resistance sheet. 13. The method of claim 12,
Among the plurality of radiation resistance sheets, the radiation resistance sheet disposed far from the center of curvature has a larger pitch between through holes than the radiation resistance sheet disposed close to the center of curvature. 9. The method of claim 8,
The support plate includes a first support plate in contact with the first plate member and a second support plate in contact with the second plate member,
The plurality of bars is attached to any one of the support plates, and the other support plate is formed with a plurality of insertion portions into which the plurality of bars are respectively inserted. 15. The method of claim 14,
A plurality of connecting portions to which each bar is connected are formed on the support plate to which the plurality of bars are attached,
A pitch between the plurality of insertion portions is smaller or greater than a pitch between the plurality of connection portions. 16. The method of claim 15,
A plurality of connecting portions to which the plurality of bars and the support plate are connected are formed to be rounded, respectively. The method of claim 1,
At least one of the first plate member and the second plate member has a first curved surface, and the support plate has a second curved surface, wherein the first curved surface and the second curved surface are bent in the same direction; The distance from the first curved surface to the center of curvature of the first curved surface is different from the distance from the second curved surface to the center of curvature of the second curved surface, or
The first curved surface and the second curved surface have the same center of curvature, and the curvature of the first curved surface and the second curved surface increases as the distance from the same center of curvature increases. a first plate member having a first temperature;
a second plate member having a second temperature different from the first temperature;
a vacuum space portion provided between the first plate member and the second plate member; and
and a supporting unit that maintains a distance between the first plate member and the second plate member, and is provided near the first plate member or next to the first plate member,
The supporting unit includes a support plate extending in the longitudinal direction of the vacuum space,
At least one of the first plate member and the second plate and the support plate each have a curved surface,
A heat resistance unit for reducing the amount of heat transfer between the first plate member and the second plate member is included, and the heat resistance unit includes a radiation resistance sheet provided in the form of a curved plate inside the space in the vacuum state,
At least one of the first plate member and the second plate and the support plate each have a curved surface,
The support plate is
a plurality of first connecting ribs extending along the circumferential direction of the support plate and bent to form a curve and spaced apart from each other; and
A vacuum insulator comprising a plurality of second connecting ribs extending along the central axis of curvature of the support plate, extending in a direction crossing the extending direction of the first connecting ribs, and spaced apart from each other. 19. The method of claim 18,
The heat resistance unit includes a conductive resistance sheet connected to at least one of the plate members,
The conductive resistance sheet is a vacuum insulator made of a material having less rigidity than the plate member and the supporting unit. 19. The method of claim 18,
A vacuum insulator configured to have a curvature value of the radiation resistance sheet between a curvature value of the first plate member and a curvature value of the second plate member. 20. The method of claim 19,
The radiation resistance sheet is a vacuum insulator made of a material having low strength and high rigidity compared to the conductive resistance sheet. a main body provided with an internal space for storing storage; and
A door provided to open and close the main body from an external space is included,
In order to supply the refrigerant to the main body,
a compressor that compresses the refrigerant;
a condenser condensing the compressed refrigerant;
an expander that expands the condensed refrigerant; and
An evaporator that evaporates the expanded refrigerant to take away heat is included,
At least one of the main body and the door includes a vacuum insulator,
In the vacuum insulator,
a first plate member having a first temperature;
a second plate member having a second temperature different from the first temperature;
a vacuum space portion provided between the first plate member and the second plate member; and
and a supporting unit that maintains a distance between the first plate member and the second plate member, and is provided adjacent to the first plate member or next to the first plate member,
The supporting unit is
a plurality of bars interposed between the first plate member and the second plate member;
a support plate extending in the longitudinal direction of the vacuum space; and
It is provided in the form of a plate inside the space of the vacuum state, and a radiation resistance sheet penetrated by the plurality of bars is included,
Each of the first plate member, the second plate member, and the support plate has a curved surface,
The support plate is
a plurality of first connecting ribs extending along the circumferential direction of the support plate, bent to form a curve, and spaced apart from each other; and
The refrigerator includes a plurality of second connection ribs extending along the central axis of curvature of the support plate, extending in a direction crossing the extending direction of the first connection ribs, and spaced apart from each other. 23. The method of claim 22,
At least one of the first plate member and the second plate member has a first curved surface, and the support plate has a second curved surface, wherein the first curved surface and the second curved surface are bent in the same direction; The distance from the first curved surface to the center of curvature of the first curved surface is different from the distance from the second curved surface to the center of curvature of the second curved surface, or
The first curved surface and the second curved surface have the same center of curvature, and the curvature of the first curved surface and the second curved surface increases as the distance from the same center of curvature increases.

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