JPH06323577A - Radiation cooling apparatus - Google Patents

Abstract

PURPOSE:To prevent dew condensation on a radiant cooling panel by arranging a polymer-based thin film, which allows favorable transmission of far infrared radiation of a particular wave length therethrough, in opposition to a radiant surface of a radiant cooling panel and forming a vacuum insulated layer between the thin film and the radiant surface of the panel. CONSTITUTION:After a blocked space in an insulated vessel 2 is made vacuous by means of a vacuum pump 6 at the start-up of operation of a cooling apparatus, a vacuum valve 12 is closed to form a vacuum insulated layer 7 so as to permit water to circulate between a thermostatic water tank 5 and a radiant cooling panel 1 for cooling of the radiant cooling panel 1. Far infrared radiation of a wave length of 8 to 10mum radiated from a person 22 in a room is transmitted through a polyethylene film 4 to be absorbed by water in the radiant cooling panel 1 of polyethylene, thereby giving a feeling of cooling to the person 22 due to radiant heat exchange. On the other hand, the vacuum insulated layer 7 between the radiant cooling panel 1 and the polyethylene film 4 prevents heat transfer from the polyethylene film 4 to the radiant cooling panel 1 through conduction and convection, so that a surface temperature of the polyethylene film 4 is kept at a temperature substantially equal to a room temperature and is prevented from becoming equal to or lower than a dew point to thereby eliminate dew condensation on the polyethylene film 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling device mainly used in houses and offices. More specifically, the present invention relates to a radiation cooling device that absorbs radiation heat from a human body.

[Prior art]

In general, the air-conditioning system is mainly of the convection type from home use to business use. The convection type cooling cools air and blows the cold air into the room for cooling. However, in the case of this convection type cooling system, since the temperature of the air in the room is to be cooled, the temperature of the blown out cold air is much lower than the desired room temperature, and the discomfort when directly touching the cold air is large.

Radiant cooling is drawing attention as a comfortable cooling environment for the convection type cooling.
The radiant cooling is to cool the building body of a building so that the ceiling or floor absorbs radiant heat from the human body to obtain a cool feeling. In the case of this convection type cooling system, it is expected that a comfortable cooling space can be realized because the temperature distribution in the room is uniform and an unpleasant fast airflow does not occur.

However, since the radiation cooling panel surface is maintained at about 20 ° C. in this radiation cooling, there is a problem that dew condensation occurs on the panel surface when the humidity is high. Therefore, in the radiant cooling system currently proposed, the method of installing the dehumidifier in the room is the mainstream. Also, accompanying this,
Technological developments related to high heat insulation and high airtightness of houses are being actively conducted.

[0005]

However, it is practically difficult to install a large dehumidifier or a plurality of dehumidifiers in terms of cost, and energy saving may not be achieved as compared with the convection type, or conversely the cost may be reduced. It is worried that it will become high. In addition, it is expected that deterioration of indoor air quality will become a problem because the heat generated from the dehumidifier and ventilation cannot be performed frequently. Further, when the cooling space is large, there is a problem that the dehumidifying effect cannot be maximized depending on the installation location of the dehumidifier. These problems also hinder the spread of radiant cooling systems.

It is an object of the present invention to provide a radiant cooling device capable of preventing dew condensation on the surface of the radiant cooling panel.

[0007]

In order to achieve such an object, the present invention provides a radiant cooling apparatus having a radiant cooling panel, which has a wavelength of 8 μm facing the radiant surface of the radiant cooling panel.
A polymer thin film which transmits far infrared rays of about 10 μm to 10 μm is arranged, and a vacuum heat insulating layer is formed between the polymer thin film and the radiation surface of the radiation cooling panel.

[0008]

Therefore, the surface temperature of the polymer thin film exposed to the outside air becomes almost equal to room temperature and does not fall below the dew point temperature due to the vacuum heat insulating layer between the radiation cooling panel and the polymer thin film. On the other hand, since it is vacuum heat insulating, heat transfer due to conduction and convection between the radiation cooling panel and the polymer thin film is blocked, but heat transfer due to radiation is not blocked. The polymer thin film satisfactorily transmits far infrared rays of 8 μm to 10 μm, which is the main wavelength of far infrared rays emitted from the human body, so that far infrared rays emitted from the human body pass through the polymer thin film. And move to the radiant cooling panel for radiant heat exchange.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be described in detail below with reference to the embodiments shown in the drawings.

FIG. 1 shows an embodiment of the radiation cooling apparatus of the present invention. The radiant cooling apparatus has a size of, for example, 90 cm square, and a plurality of such radiant cooling apparatuses are combined and installed on the ceiling surface according to the size of the room.

The radiant cooling apparatus includes a radiant cooling panel 1 which can be cooled by circulating water or another cooling medium inside or by an electric effect, a radiant cooling panel 1 surrounding the radiant cooling panel 1, and a back surface of the radiant cooling panel 1. A heat-insulating container 2 that prevents heat from entering from the side and a polymer thin film that is arranged so as to face the radiation surface 3 in front of the radiation cooling panel 1 and has a property of favorably transmitting far infrared rays having a wavelength of about 8 μm to 10 μm. Four
A constant temperature water tank 5 connected to the radiation cooling panel 1, a vacuum pump 6 connected to the recess 8 of the heat insulating container 2, and the radiation cooling panel 1 and the polymer thin film 4 by the vacuum pump 6.
And a vacuum heat insulating layer 7 which is formed at least between and.

A concave portion 8 for accommodating the radiation cooling panel 1 is formed on the lower surface side of the heat insulating container 2 made of a heat insulating material, and the radiation cooling panel 1 is provided in the concave portion 8 via a holder 9 made of a highly heat insulating material. It is fixed and supported. Therefore, it is possible to sufficiently prevent heat from flowing into the radiation cooling panel 1 from outside the heat insulating container 2 through the heat insulating container 2 by conduction.

The radiation cooling panel 1 is structured to be cooled by water supplied from the constant temperature water tank 5, and is made of a polymer such as polyethylene which allows far infrared rays of about 8 μm to 10 μm to be well transmitted. Further, in the opening portion of the concave portion 8 of the heat insulating container 2, facing the radiation surface 3 of the radiation cooling panel 1,
A polymer thin film 4 is provided that allows far infrared rays of about 8 μm to 10 μm to pass therethrough. Polyethylene, for example, is preferably used as the polymer thin film 4. Since polyethylene transmits far-infrared rays having a main wavelength of 8 μm to 10 μm emitted from the human body, the far-infrared rays emitted from the human body pass through the polyethylene film 4 and the wall of the radiant cooling panel 1 and are contained in the radiant cooling panel 1. It is considered that the components directly absorbed by water increase and the efficiency of radiant heat exchange between the human body and the radiant cooling panel 1 becomes good. The material constituting the radiation cooling panel 1 and the polymer thin film 4 stretched over the heat insulating container 2 are not particularly limited to polyethylene, and have a property of permitting transmission of far infrared rays having a wavelength of 8 μm to 10 μm emitted from the human body. Any polymer material can be used.

The closed space formed by the recess 8 of the heat insulating container 2 and the polyethylene film 4 is sealed by a seal frame 10 to prevent outside air from entering therein. The vacuum pump 6 and the closed space in the recess 8 are connected to each other through a pipe 11 penetrating the recess 8 so that a vacuum can be obtained. A vacuum valve 12 is provided on the pipe 11. Therefore, the vacuum pump 6
After the closed space, especially the space between the radiation cooling panel 1 and the polyethylene film 4 is evacuated, the vacuum valve 12
The vacuum is maintained by closing. As a result, the vacuum heat insulating layer 7 is formed between the radiation cooling panel 1 and the polyethylene film 4, and the heat transfer due to conduction and convection from the polyethylene film 4 to the radiation cooling panel 1 is suppressed.
Since the polyethylene film 4 comes into contact with the outside air, the temperature of the surface of the polyethylene film 4 becomes substantially equal to room temperature, does not fall below the dew point, and dew condensation does not occur on the surface of the polyethylene film 4.

The polyethylene film 4 is reinforced from the back side by a grid-shaped reinforcing frame 13 made of hard polyethylene. Therefore, the polyethylene film 4 is prevented from coming into contact with the radiation cooling panel 1 due to the pressure difference between the vacuum heat insulating layer 7 on the back surface side of the polyethylene film 4 and the outside air on the front surface side.

In addition, the inner surface of the recess 8 of the heat insulating container 2 and the surfaces other than the radiation surface 3 of the radiation cooling panel 1, ie, the side surface 14 and the back surface 15, have good high reflection characteristics in the visible light region, near infrared light and far infrared light. Thin metal film having, for example, aluminum thin film
6 is glued. Thereby, heat inflow due to radiant heat exchange to the side surface 14 and the back surface 15 of the heat insulating container 2 and the radiation cooling panel 1 can be prevented as much as possible. Further, it is possible to prevent heating of the heat insulating container 2 by external light (especially visible light and near infrared rays) that penetrates the polyethylene film 4 and enters the concave portion 8 of the heat insulating container 2 as much as possible. That is, in the case of the present embodiment, since it is a ceiling surface installation type, it mainly takes the heat from the human body or the like facing the radiation surface 3 of the radiation cooling panel 1 and shuts off the heat radiated from the ceiling surface or the wall surface to cool the room. I try to improve the effect.

A constant temperature water tank 5 is connected to the radiant cooling panel 1 via a water supply pipe 17 and a drain pipe 18, and a circulation pump 19 is provided in an intermediate portion between the water supply pipe 17 and the drain pipe 18. A cooler 20 for cooling water is installed inside the constant temperature water tank 5. Therefore, the radiation cooling panel 1 is cooled by the water supplied from the constant temperature water tank 5 through the water supply pipe 17, and the water returned to the constant temperature water tank 5 through the drain pipe 18 is cooled again to the set temperature by the cooler 20. .

A controller 21 for controlling the cooler 20, the circulation pump 19, the vacuum pump 6 and the vacuum valve 12 is installed in the room. The occupant 22 is the controller 21
By operating the cooler 20 to adjust the set water temperature of the constant temperature water tank 5, or to control the circulation pump 19 to adjust the amount of water flowing between the constant temperature water tank 5 and the radiant cooling panel 1. The vacuum degree of the vacuum heat insulation layer 7 can be adjusted by controlling the vacuum pump 6 as needed.

In this embodiment, the radiation cooling panel 1 is of the water cooling type, but it may be cooled by flowing a cooling medium other than water, or the panel 1 which can be cooled by an electric effect such as a Peltier element. You may adopt it.

The radiant cooling apparatus of the present embodiment constructed as described above is used, for example, installed on the ceiling as shown in FIG. 1, and radiates between the human body and the radiant cooling panel regardless of indoor humidity. By exchanging heat, it is possible to give a comfortable feeling of cooling to a person in the room without causing dew condensation.

First, at the start of the operation of the cooling device, the vacuum pump 6 is operated to bring the closed space in the heat insulating container 2 into a vacuum state, and then the vacuum valve 12 is closed to form the vacuum heat insulating layer 7. Then, water is circulated between the constant temperature water tank 5 and the radiation cooling panel 1 to cool the radiation cooling panel 1.

Far-infrared rays having a wavelength of 8 μm to 10 μm emitted from the occupants 22 penetrate the polyethylene film 4 and are directly absorbed by the water in the radiant cooling panel 1 made of polyethylene. A coolness is given to the occupants 22.

On the other hand, since the vacuum heat insulating layer 7 is interposed between the radiant cooling panel 1 and the polyethylene film 4, heat transfer due to conduction and convection from the polyethylene film 4 to the radiant cooling panel 2 is blocked, and the polyethylene film is prevented. The temperature of the surface of the membrane 4 is maintained at a temperature almost equal to room temperature and does not fall below the dew point, so that no condensation occurs on the surface of the polyethylene membrane 4.
Therefore, even if the humidity in the room is high or the humidity constantly changes due to ventilation, dew condensation does not occur on the surface of the polyethylene film 4. Here, heat may be transferred from the polyethylene film 4 to the radiation cooling panel 1 by radiation, and the polyethylene film 4 may be lowered, but if the polyethylene film 4 is thin, for example, about 0.1 mm. ,
Even if heat is transferred from the polyethylene film 4 to the radiant cooling panel 1, heat is supplied to the polyethylene film 4 by radiant heat exchange with the occupants 22 and convective heat transfer of indoor air. It is considered that there is no problem in practical use because it is considered that the front surface and the back surface are always almost equal to room temperature.

Moreover, if the film thickness is about 0.1 mm, the transmittance of far infrared rays having a wavelength of 8 μm to 10 μm is about 80%, which is not a practical problem for radiant heat exchange. This was determined experimentally by measuring the spectral transmittance for each wavelength using a polyethylene film having a thickness of 0.1 mm as a sample. The result of the experiment is shown in FIG. In FIG. 4, the horizontal axis represents wavelength (μm) and the vertical axis represents transmittance. From FIG. 4, this sample has a wavelength of 8
It was found that 80% of far infrared rays having an average wavelength of 10 μm were transmitted.

The above-described embodiment is an example of a preferred embodiment of the present invention, but the present invention is not limited to this, and various modifications can be made without departing from the gist of the present invention.

[0026]

As is apparent from the above description, in the radiant cooling apparatus of the present invention, the radiant cooling panel facing the radiant cooling panel has a wavelength of 8 mm.
Since the polymer thin film which transmits far infrared rays of around 10 μm to 10 μm is arranged well, and the vacuum heat insulating layer is formed between the polymer thin film and the radiation cooling panel, the radiation cooling panel and Condensation occurs on the surface of the polymer thin film because the vacuum insulating layer between the polymer thin film and the polymer thin film prevents heat transfer due to conduction and convection and the surface temperature of the polymer thin film exposed to the outside air is almost equal to room temperature and does not fall below the dew point. The wavelength emitted from the occupants is 8 μm.
Far infrared rays of 10 μm to 10 μm satisfactorily pass through the polymer thin film and undergo radiative heat exchange with the radiant cooling panel, so that the person in the room can feel a cool sensation.

Further, according to the radiant cooling apparatus of the present invention, since dew condensation does not occur on the surface of the polymer thin film, it is not necessary to install a large capacity or a plurality of dehumidifiers, and equipment cost and running cost are greatly increased. It can reduce the energy consumption.

Further, according to the radiant cooling apparatus of the present invention, since there is no concern of dew condensation, it is possible to ventilate during cooling, and it is possible to constantly supply fresh air to the room and prevent the room air from becoming dirty during cooling. it can.

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of a radiation cooling device of the present invention.

FIG. 2 is a cross-sectional view of a main part of the radiant cooling apparatus in FIG.

FIG. 3 is a perspective view partially showing a polymer thin film.

FIG. 4 is a graph showing the spectral transmittance of a polyethylene film.

[Explanation of symbols]

 1 radiation cooling panel 2 heat insulation container 3 radiation surface 4 polyethylene membrane (polymer thin film) 6 vacuum pump 7 vacuum insulation layer

Claims (1)

[Claims] 1. A radiant cooling apparatus including a radiant cooling panel, wherein a wavelength of 8 is provided opposite to a radiant surface of the radiant cooled panel.
Radiant cooling, characterized in that a polymer thin film that satisfactorily transmits far-infrared rays of about 10 μm to 10 μm is arranged, and a vacuum heat insulating layer is formed between the polymer thin film and the radiation surface of the radiation cooling panel. apparatus.