JPS6352296B2 - - Google Patents

Abstract

PURPOSE:To contrive to enhance the cooling and heating functions by a structure wherein a radiating surface is covered with substance, which has high transmittance with respect to visible rays and high absorption factor with respect to infrared rays. CONSTITUTION:A back panel 2, at the dent parts of which water pipes 3 is equipped, is arranged on one side of a heat insulating material 1. A radiating surface panel 4 is arranged so as to contact with both the water pipes 3 and the back panel 2. A selective radiation layer 7 comprising an inside layer 5 and an outside layer 6 is formed onto the radiating surface panel 4. The inside layer 5 consists of a layer of substance with high reflection factor with respect to visible rays such as aluminum deposit or the like, while the outside layer 6 consists of a layer of substance with high transmittance with respect to visible rays and high absorption factor with respect to infrared rays such as magnesium oxide film or the like. In such a structure as mentioned above, a radiant panel with excellent performance for cooling and heating due to heat transfer by radiation is obtained while keeping irradiation effect as same as before.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a radiant panel, and more particularly to a radiant panel for cooling and heating a room or the like by radiant heat transfer.

The radiant panel has a hollow pipe for circulating a heat medium through a heat insulating material layer, and has a radiant surface on one side of the hollow pipe. Then, radiant heat is transferred via the radiant surface to cool or heat the room or the like.

In such a radiant panel, the radiant surface has conventionally been painted black, or metal aluminum has been used for the purpose of facilitating heat transfer from the heat medium to the radiant surface. However, in the case of a black-painted radiation surface, the radiation rate is high, but the absorption rate of visible light is also high, and it absorbs natural light such as sunlight from the outside, as well as light rays from indoor lighting, so the amount of radiation is only small. However, there is a problem that the room becomes dark and the lighting effect is poor. On the other hand, in the case of a radiating surface made of metal aluminum, since the reflectance is high, radiant heat transfer is insufficient due to the law of (1-reflectance)=emissivity. Therefore, all conventional radiant panels having a radiant surface are unable to absorb and radiate sufficiently, and therefore have low efficiency in cooling and heating indoor rooms.

An object of the present invention is to provide a radiant panel that maintains the irradiation effect and has good performance for cooling and heating by radiant heat transfer.

The present invention has a structure in which the radiation surface is covered with a material that has a high reflectance for visible light and a material that has a high transmittance for visible light and a high absorption for infrared rays. It is designed to have selective radiation properties.

Embodiments of the present invention will be described below based on the accompanying drawings.

FIG. 1 is a sectional view showing an embodiment of the present invention, in which a back panel 2 is provided on one side of a heat insulating material 1, and a water pipe 3 is provided in a concave portion of the back panel 2. A radiation surface panel 4 is provided in contact with the water tube 3 and the back panel 2, and then a selective radiation layer 7 consisting of an inner layer 5 and an outer layer 6 is formed. The inner layer 5 is a layer made of a material that has a high reflectance for visible light, and the outer layer 6 is a layer that is made of a material that has a high transmittance for visible light and a high absorption for infrared rays.

As the inner layer 5, it is preferable to use one that forms a surface close to a mirror surface, such as a vapor-deposited layer of aluminum or a plating layer of nickel, but one that provides a white surface with a relatively high reflectance to visible light; For example, a magnesium oxide film formed by a magnesium thermal spraying method can also be used. The outer layer 6 is preferably made of glass or a transparent resin such as acrylic resin, and these materials are made to cover the entire surface of the inner layer 5 by means of welding or the like.

Next, the operation of the radiant panel having the structure shown in FIG. 1 will be explained with reference to FIGS. 2 and 3.

In Figure 2, A indicates the light absorption rate of a 3 mm layer of acrylic resin, and B indicates the light absorption rate of a 3.2 mm layer of glass.The materials that can make up these outer layers are both extremely high in the visible light range. It shows the transmittance. Therefore, the outer layer has a property of transmitting sunlight and indoor illumination light having a wavelength of around 0.35 to 0.75 μm.

In Figure 2, C is the blackbody emissivity distribution at 40°C.
D shows the blackbody emissivity distribution at 10°C.
Here, D is the relative emissivity when the black body emissivity at 40° C. is taken as 100. The blackbody emissivity distribution D at 40°C is approximately 3 around the wavelength of approximately 9 μm.
It spans ~30μm. On the other hand, the outer layer (in the case of A) has a property of absorbing and not transmitting in the long wavelength range from approximately 2.5 μm. This indicates that the outer layer absorbs radiation from objects at around 40°C well.

Also, according to Kirchhoff's law, the following law strictly holds. ελ=αλ ελ: Monochromatic emissivity αλ: Monochromatic absorption rate Therefore, if the temperature of the outer layer is around 40°C, it will emit the same amount of radiation as a blackbody at around 40°C. Furthermore, the radiation of an object is proportional to the fourth power of the absolute temperature of the object's surface, so if the temperature of the object's surface is 20℃,
The temperature of the surface of the object decreases to 71% of the radiation of 40℃.
At 10°C, D decreases to 60% of the radiation at 40°C, as shown in Figure 2. In FIG. 2, E indicates the spectral absorption characteristics of the black painted surface, and the absorption decreases from a wavelength of 9 μm toward longer wavelengths. Therefore, it can be seen that infrared radiation is also reduced on a black painted surface.

The cooling and heating effects of the radiant panel will be explained based on such spectral distribution characteristics.

In the case of cooling, visible light X passes through the outer layer 6, is reflected by the inner layer 5, and exits to the outside world, as shown in FIG. As a result, the visible light rays X are used as they are as high potential energy light. When the infrared rays Y reach the outer layer 6, they are absorbed there and changed into heat. However, since the temperature of the heat medium (water flowing through the water tube 3 in this case) 3A is lower than the room temperature, heat is transferred to the heat medium 3A side. Begin conduction. At this time, that is, when cooling is being performed, the surface temperature of the outer layer is around 15°C, so re-radiation Z into the room can be suppressed. Therefore, during cooling, only infrared rays from the human body or other objects in the room are unilaterally absorbed without absorbing visible rays that can be used as light. Furthermore, as shown in FIG. 2, the outer layer made of acrylic resin or glass has a higher absorption rate of infrared rays than the black painted surface, resulting in higher cooling efficiency.

In the case of heating, visible light is reflected by the inner layer 5 as in the case of cooling, maintaining the brightness and lighting efficiency of the room. Infrared rays are absorbed by the outer layer 6, but during heating, since the heat medium 3A side is at a high temperature, the heat is not conducted to the heat medium side, but is radiated from the outer layer 6. At this time, since the outer layer 6 has a higher infrared absorption rate (and therefore infrared radiation emissivity) than the black painted surface, the heating efficiency is good.

In the present invention, in addition to the selective radiation layer having the two-layer structure shown in FIG. 1, it is also possible to use a selective radiation layer having a single-layer structure. In this case, a material with a high reflectance for visible light is dispersed on the surface of the radiation panel 4 shown in FIG. A coated layer is formed. As such a selective radiation layer, for example, powder of titanium oxide and/or zinc oxide is dispersed in a transparent resin such as acrylic resin dissolved in an organic solvent, etc., and this is applied to the four radiant panels shown in FIG. A layer coated on and dried is suitable.

Even in the case of a selective radiation layer with a single layer structure, visible light is reflected by the material coated in the transparent resin and is used as light, while infrared rays are absorbed by the coating layer made of transparent resin, so it is a two-layer structure. Similarly, the efficiency of cooling and heating can be increased while maintaining the brightness of the room.

Furthermore, in the present invention, when the radiation surface panel 4 shown in FIG. An outer layer made of resin or glass may be provided so that the radiation surface panel 4 has the function of the radiation surface panel and the function of the inner layer 5 shown in FIG. 1.
In this case, after visible light passes through the outer layer, it is reflected by the mirror-like radiant panel, and infrared rays are absorbed by the outer layer, so as in the previous example, the brightness of the room can be maintained while cooling and heating can be controlled. Efficiency can be increased.

As described above, according to the present invention, visible light is reflected and only infrared rays from the human body and objects in the room are absorbed, so efficient cooling can be performed while maintaining the brightness of the room. Since the radiation surface has a higher radiation rate than a black surface, efficient heating can be performed.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view showing one embodiment of the radiant panel of the present invention, Figure 2 is a diagram showing the spectral absorption characteristics of various materials, and Figure 3 is a diagram showing the heating and cooling effect of the radiant panel shown in Figure 1. It is an explanatory diagram. 1...Insulating material, 2...Back panel, 3...Water pipe, 4...Radiation surface panel, 5...Inner layer, 6...
Outer layer, X...visible light, Y...infrared rays, 3A...
...Heating medium.

Claims (1)

[Scope of Claims] 1. In a radiant panel for radiant cooling and heating equipped with a hollow pipe in which a heat medium circulates, a near-mirror surface layer such as a nickel plating layer is formed as an inner layer of the radiant surface of the radiant panel, A radiation panel characterized in that a selective radiation layer is formed by covering the inner layer with an outer layer made of a transparent resin such as glass or acrylic resin. 2. The radiant panel according to claim 1, wherein a selective radiant layer in which powders of titanium oxide, zinc oxide, etc. are dispersed in a layer made of transparent resin is formed as a radiant surface of the radiant panel.