JP4743365B2 - Wall structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a wall structure, and more particularly to a wall structure including a heat insulating layer having high sunlight reflectance and high infrared emissivity.
[0002]
[Prior art]
This type of wall structure is used in, for example, buildings such as residences, condominiums, huts, and warehouses, and structures such as low-temperature tanks, cars, trains, and artificial satellites. As shown in the figure, a structure in which the heat insulating layer 12 is simply provided on the wall material 11 is employed.
[0003]
The heat insulating layer 12 is formed of a white paint or heat insulating paint having the following functions 1) to 3) to prevent heat energy from outside the building or structure from entering the inside. It is configured to prevent it.
[0004]
1) Since the sunlight reflectance is high, the sunlight from the outside air is reflected to suppress the temperature rise on the outer wall surface of the building or structure, and the thermal energy of sunlight enters the building or structure. To prevent.
2) Since the thermal conductivity is low, the ambient temperature of the outside air is difficult to conduct to the inside of the building or structure, and the thermal energy of the outside air is prevented from entering the inside of the building or structure by heat conduction.
3) Since the infrared emissivity is high, the temperature on the extreme surface side of the outer wall is cooled by the radiation cooling phenomenon, and the heat energy of the outside air is prevented from entering the inside of the building or structure by infrared radiation. The radiation cooling phenomenon is as follows. In other words, in the atmosphere, there is a region with a very high transmittance in the wavelength range of 8 to 13 μm (so-called “atmosphere window”), so infrared rays emitted from objects in the atmosphere in such a wavelength range pass through the atmosphere. Will reach the upper atmosphere or the universe. Therefore, when the amount of infrared rays radiated from an object is large in such a wavelength range, and the total infrared radiant heat emitted from the object is higher than the total infrared radiant heat that flows in by radiation from other objects or the lower atmosphere. The object is radiatively cooled, which is called a radiative cooling phenomenon.
[0005]
[Problems to be solved by the invention]
According to the conventional wall structure described above, the surface of the heat insulating layer 12 is in direct contact with the outside air, and thus has the following problems.
In other words, the function 3) of the heat insulating layer 12 described above causes the extreme surface side 12a to have a temperature that rises in a short time because it is counteracted by the heat transfer effect from the outside air that is in direct contact with it, that is, in the air, although the temperature is lowered by the radiation cooling phenomenon. There was a problem that it was easy to do.
For this reason, the radiative cooling phenomenon cannot be used effectively, and as a result, it is not possible to sufficiently prevent the heat energy from the outside of the building or structure from entering the inside of the building or structure. There was room left.
[0006]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a wall structure that can make it difficult for heat energy from the outside of a building or structure to enter the inside thereof. is there.
[0007]
[Means for Solving the Problems]
As illustrated in FIG. 1, the characteristic configuration of the invention according to claim 1 is a white acrylic resin material having high solar reflectance and high infrared emissivity in a wavelength range of 8 to 13 μm on the surface side of the wall material. The first heat insulating layer formed from the above is provided, and the second heat insulating layer made of polyethylene foam having low thermal conductivity and high infrared transmittance in the wavelength range of 8 to 13 μm is provided on the first heat insulating layer. It is in.
[0008]
In the present invention, the wall structure means all parts of the structural part of the building or structure that come into contact with the outside air, and the side wall part as well as the structure of the upper wall part, that is, the roof part and the ceiling part. Is included.
[0009]
[Function and effect]
Since the first heat insulation layer has high solar reflectance, it suppresses the temperature rise of the outer wall surface of the building or structure by reflecting sunlight from the outside air, so that the thermal energy of sunlight can be absorbed by the building or structure. It is possible to prevent intrusion into the inside.
And the surface of the 2nd heat insulation layer provided on the 1st heat insulation layer will be exposed to the outside air, but since the second heat insulation layer has low thermal conductivity, the ambient temperature of the outside air is the building or structure It is possible to prevent the heat energy of the outside air from entering the inside of the building or structure by heat conduction.
[0010]
Further, since the first insulation layer has a high infrared emissivity in the wavelength range of 8～13Myuemu, that can emit inner clogging buildings and structures thermal energy from the inside as an infrared, infrared its emitted 8 Since it transmits through the second heat insulating layer having a high infrared transmittance in the wavelength range of ˜13 μm and is emitted to the outside air side, the extreme surface side of the first heat insulating layer is cooled by the radiation cooling phenomenon. Moreover, the pole surface side of the first heat insulating layer to be cooled is in contact with the second heat insulating layer, not the outside air, and the second heat insulating layer has low thermal conductivity. It becomes difficult for the surface to rise in temperature due to heat transfer, and the radiation cooling state can be maintained for a relatively long period of time so that the radiation cooling phenomenon can be used effectively.
In addition, the infrared emissivity of the first heat insulating layer is preferably as the infrared emissivity in the wavelength range of 8 to 13 μm is higher because the radiation cooling phenomenon is promoted. For the same reason, the infrared emissivity of the second heat insulating layer is preferable. In particular, the higher the transmittance of infrared rays in the wavelength range of 8 to 13 μm, the more preferable the transmittance.
[0011]
Therefore, as a result, the heat energy from the outside of the building or structure can be made harder to enter the inside thereof, for example, when it is necessary to keep the inside of the building or structure at a constant temperature (for example, in a low temperature tank). In some cases, the amount of heat energy flowing into the interior of a building or structure can be reduced to reduce the power consumption required for temperature control inside the building or structure.
[0012]
[0013]
[0014]
In addition, as mentioned above, although the code | symbol was written in order to make contrast with drawing convenient, this invention is not limited to the structure of an accompanying drawing by this entry.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an explanatory cross-sectional view of an embodiment of a wall structure according to the present invention.
[0016]
As shown in FIG. 1, the said wall structure provides the 1st heat insulation layer 2 with a high sunlight reflectance and a high infrared emissivity on the surface side of the wall material 1, and on the 1st heat insulation layer 2, A second heat insulating layer 3 having a low thermal conductivity and a high infrared transmittance is provided.
[0017]
The wall material 1 is an outer wall material of a building or a structure, and corresponds to, for example, the outer wall itself or an exterior material (for example, a heat insulating material) attached to the outer wall.
[0018]
The first heat insulating layer 2 may be formed of any material as long as it has high solar reflectance and high infrared emissivity. For example, a white acrylic resin material (acrylic) If it is formed from a resin emulsion paint or the like, the first heat insulating layer 2 can be easily provided by coating or the like, which is convenient. Needless to say, the first heat insulating layer 2 is not limited to coating, and any other method may be adopted as long as at least a layer (or film) having a certain thickness can be formed. For example, a sheet-like material may be stuck on the wall material 1, or a material on powder may be adhered on the wall material 1.
Note that the sunlight reflectance mainly means the reflectance of sunlight in the wavelength range of 0.3 μm to 2.5 μm.
[0019]
Incidentally, the thermal conductivity of the first heat insulating layer 2 may be anything, but as described above, the pole surface side 2a of the first heat insulating layer 2 is cooled by the radiation cooling phenomenon, so that the higher the heat conductivity is, The cooling action works more efficiently on the wall material 1 side, and as a result, the amount of heat energy flowing from the outside air to the wall material 1 side can be further reduced, which is preferable. . And the thickness of the 1st heat insulation layer 2 is more preferable, so that it is thin from the same reason.
[0020]
The second heat insulating layer 3 may be formed of any material as long as it has a low thermal conductivity and a high infrared transmittance. For example, the second heat insulating layer 3 may be made of polyethylene resin, polymethylpentene resin, odor, or the like. If it forms from potassium halide, the 2nd heat insulation layer provided with sufficient infrared emissivity and thermal conductivity can be provided, and it is suitable. And in providing the 2nd heat insulation layer 3, as long as a layer (or film | membrane) of at least fixed thickness can be formed, what kind of method may be employ | adopted, for example, a slurry-like material is applied on the 1st heat insulation layer 2. It may be applied to the first heat insulating layer 2, or a material on the powder may be adhered to the first heat insulating layer 2. Of course, the second heat insulating layer 3 may have a function of reflecting sunlight.
[0021]
According to the wall structure according to the present invention having the above-described configuration, it is possible to make it difficult for heat energy from the outside of the building or structure to enter the inside thereof, for example, the inside of the building or structure When it is necessary to maintain a constant temperature (for example, in the case of a low-temperature tank), the consumption required for temperature control inside the building or structure is reduced by reducing the amount of heat energy flowing into the building or structure. Electric power can be reduced.
[0022]
【Example】
Specific examples and comparative examples for confirming the effects of the present invention are shown below, but the present invention is not limited thereto.
[0023]
Example 1
A computer simulation was performed assuming a low-temperature tank having a wall structure according to the present invention as shown in FIG. At this time, the holding temperature inside the low temperature tank is set to T _b (K
), And T _a (K), the temperature of the outside atmosphere, the surface side of the wall structure, that is, the second heat insulating layer 3
Let T _s (K) be the surface temperature.
[0024]
Then, T _s is determined by the heat gradient from the atmosphere depending on the wind speed and the temperature gradient between the temperature T _b of the surface 1 a of the cold tank. That is, the second heat insulating layer 3 is assumed to be formed of polyethylene foam, and the heat conductivity of the polyethylene foam is measured using 0.036 (W / mK) to transfer heat from the atmosphere by Mac Adams. If given by the empirical formula (Sakae Tanemura, Solar Energy Utilization Handbook, Japan Solar Energy Society, 1985, p. 180), the following formula (1) h (T _a −T _s ) = α (T _s −T _b ) / T (1)
T _s can be derived from Where α is the thermal conductivity of the second heat insulating layer (0.036 (W / mK)), t is the thickness of the wall structure (that is, the total thickness of the first heat insulating layer and the second heat insulating layer), In this embodiment, assuming that the thickness of the first heat insulating layer is sufficiently thin, the thickness of the second heat insulating layer is defined as the total thickness, and t = 1 cm. And h is the heat transfer coefficient from the atmosphere given by the empirical formula by McAdams.
h = 5.7 + 3.8v (2)
Is derived from However, v (m / s) is the wind speed on the surface side of the wall structure, and in this example, it was the wind speed of the atmosphere.
[0025]
Using the above conditions, the amount of heat flowing into the low temperature tank surface 1a when T _a = 300K and T _b = 250K was calculated.
The inflow heat quantity can be obtained from the balance of 1) infrared radiation from the atmosphere, 2) heat conduction to the surface of the low temperature tank through the wall structure, and 3) infrared radiation from the surface of the low temperature tank through the wall structure.
1) Infrared radiation from the atmosphere is 300K blackbody radiation and atmospheric emissivity (or absorption) (RMGoodyandY.L.Yung, AtmosphericRadiation, OxfordUniversity)
Obtained by multiplying Press, 1989, p.4).
2) Heat conduction to the cryogenic tank surface through the wall structure is given by α (T _s −T _b ) / t.
3) Infrared radiation from the surface of the cryogenic tank through the wall structure was approximated by 250K blackbody radiation.
In addition, the sunlight reflectance of the first heat insulating layer approximated to 1, and it was assumed that there was no heat rise of the wall structure due to sunlight.
A calculation result of the inflow heat amount when the wind speed v changes from 0 m / s to 10 m / s is shown by a dotted line in FIG.
[0026]
Example 2
Computer simulation was performed in the same manner as in Example 1 except that the holding temperature T _{b in the} low-temperature tank was set to 200 (K). The calculation result is shown by the dotted line in FIG.
[0027]
Comparative Example 1
Computer simulation was performed assuming a cryogenic tank having a wall structure as shown in FIG. 4 described in detail in the section of the prior art. At this time, the holding temperature inside the low-temperature tank is T _b (K), the outside air temperature is _Ta (K), and the surface side of the wall structure, that is, the temperature of the surface 12a of the heat insulating layer 12 is T _s (K ).
[0028]
In this comparative example 1, since it is necessary to consider the radiation cooling phenomenon of the surface 12a due to infrared radiation of the heat insulating layer 12, the T _s is the heat transfer from the atmosphere depending on the wind speed and the temperature of the surface 11a of the low temperature tank. the thermal gradient between the T _b, is determined by the balance between infrared radiation from the infrared radiation and the heat insulating layer 12 from the atmosphere. As can be compared with Example 1 described above, the thermal conductivity of the heat insulating layer 12 is 0.036 (W / mK), and the heat transfer from the atmosphere is empirically expressed by Mac Adams (Sakae Tanemura, Sun Given in the Energy Utilization Handbook, Japan Solar Energy Society, 1985, p. 180), the following equation (3)
h (T _a −T _s ) + E _atmosphere = α (T _s −T _b ) / t + E _surface (3) T _s can be derived. However, (alpha) is the heat conductivity (0.036 (W / mK)) of the heat insulation layer 12, t is the thickness of a wall structure (namely, thickness of the heat insulation layer 12), and was set to 1 cm in this comparative example. . E _atmosphere is infrared radiation from the atmosphere, and E _surface is infrared radiation from the surface 12 a of the heat insulating layer 12. Note that h is given by the above equation (2) as in the first embodiment.
[0029]
Using the above conditions, the amount of heat flowing into the low temperature tank surface 11a when T _a = 300K and T _b = 250K was calculated.
The inflow heat quantity can be obtained from the balance of 1) heat conduction to the surface of the low temperature tank through the wall structure and 2) infrared radiation from the surface of the wall structure (heat insulation layer).
1) Heat conduction to the cryogenic tank surface through the wall structure is given by α (T _s −T _b ) / t.
2) Infrared radiation from the surface of the wall structure was approximated by 250K blackbody radiation.
In addition, the solar light reflectance of the heat insulation layer approximated to 1, and it was assumed that there was no heat rise of the wall structure by sunlight.
The calculation result of the inflow heat amount when the wind speed v changes from 0 m / s to 10 m / s is shown by the solid line in FIG.
[0030]
Comparative Example 2
Computer simulation was performed in the same manner as in Comparative Example 1 except that the holding temperature T _{b in the} low temperature tank was set to 200 (K). The calculation result is shown by the solid line in FIG.
[0031]
From the results shown in FIG. 2, when the holding temperature T _b = 250 (K) inside the low-temperature tank, both Example 1 and Comparative Example 1 monotonously increase the amount of heat flowing into the low-temperature tank surface along with the wind speed. However, in Example 1, the inflow heat amount value is always lower than that of Comparative Example 1, and is 1/3 to 1/2 of that of Comparative Example 1 especially at wind speed v = 2 (m / s) or more. It turns out that it is a value.
Also from the results shown in FIG. 3, when the holding temperature T _b = 200 (K) inside the low temperature tank, the second embodiment is more than the second comparative example when the wind speed v is 2.7 (m / s) or higher. It can be seen that the inflow heat value is also low.
Therefore, according to the wall structure which concerns on this invention, it has confirmed that the heat energy from the outer side of a building or a structure can certainly make it difficult to penetrate | invade those inside.
[Brief description of the drawings]
FIG. 1 is an explanatory sectional view of a wall structure according to the present invention. FIG. 2 is an explanatory view showing the effect of the wall structure according to the present invention. FIG. 3 is an explanatory view showing the effect of the wall structure according to the present invention. Cross-sectional view of conventional wall structure
DESCRIPTION OF SYMBOLS 1 Wall material 1a Surface of wall material 2 First heat insulation layer 2a Surface of first heat insulation layer 3 Second heat insulation layer 3a Surface of second heat insulation layer 11 Wall material 11a Surface of wall material 12 Heat insulation layer 12a Surface of heat insulation layer

Claims (1)

On the surface side of the wall material, a first heat insulating layer formed from a white acrylic resin material having a high sunlight reflectance and a high infrared emissivity in a wavelength range of 8 to 13 μm is provided, and on the first heat insulating layer A wall structure provided with a second heat insulating layer made of polyethylene foam having low thermal conductivity and high infrared transmittance in the wavelength range of 8 to 13 μm .

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