KR102020593B1 - Floor Heating Structure With Thermal Conductive Cement Mortar and Method for Constructing the Same - Google Patents

Abstract

The present invention relates to a floor heating structure using a thermally conductive cement mortar and a construction method thereof. The floor heating structure using the thermally conductive cement mortar according to the present invention comprises: a hot water pipe constructed on a floor; The hot water pipe is embedded on the bottom surface to be embedded, characterized in that it comprises a carbon nanotube, or graphene, or a cement mortar layer incorporating carbon nanotubes and graphene.

Description

Floor Heating Structure With Thermal Conductive Cement Mortar and Method for Constructing the Same}

The present invention relates to a floor heating structure and a construction method thereof, and more particularly, a floor heating floor structure and a construction thereof that can improve heating efficiency by using a cement mortar mixed with carbon nanotubes and graphene having high thermal conductivity. It is about a method.

The general residential floor structure of our country has a generalized ondol heating structure that embeds hot water pipes and heats the floor using hot water inside the hot water pipes. However, the conventional floor heating structure has a long time for the hot water heat of the pipe is transferred to the entire floor through the mortar due to the finishing mortar layer. In addition, if the installation amount of the hot water pipes is increased to increase heating efficiency, problems such as construction cost and heating cost occur.

In order to solve this problem, the floor heating structure is constructed by incorporating metal powder, graphite, or steel fiber into cement mortar as shown in the following prior art documents.

However, the method of incorporating metal powder, graphite, or steel fiber into the cement mortar has a problem in that the effect of increasing the thermal conductivity is not very high or expensive to manufacture.

Republic of Korea Patent Registration No. 10-0519443 (September 28, 2005 registration): Cement mortar to be installed on the floor having a heating structure and its manufacturing method Republic of Korea Patent Publication No. 10-2002-0001283 (January 09, 2002 published): Floor heating structure using steel fiber mortar

The present invention is to solve the above problems, an object of the present invention by uniformly mixing the carbon nanotubes and / or graphene excellent in thermal conductivity to obtain a thermally conductive cement mortar that can obtain a high thermal conductivity effect at low cost The present invention provides a floor heating structure and a construction method thereof.

Floor heating structure according to the present invention for achieving the above object, the hot water pipe is constructed on the floor; The hot water pipe is embedded on the bottom surface to be embedded, characterized in that it comprises a carbon nanotube, or graphene, or a cement mortar layer incorporating carbon nanotubes and graphene.

According to another aspect of the invention, (a) installing a hot water pipe on the bottom surface; (b) mixing the cement with sand and silica fume to dry the beam for a set time; (c) incorporating carbon nanotubes or graphene, or carbon nanotubes and graphene into the mixture of cement, sand, and silica fume, and performing a dry beam for a predetermined time; (d) adding water to the mixture and stirring for a set time to produce cement mortar; (e) A method of constructing a floor heating structure comprising the step of embedding the cement mortar on the bottom surface to bury a hot water pipe.

According to the present invention, by incorporating carbon nanotubes and / or graphene, which are very excellent in thermal conductivity and can be purchased at low cost, into cement, a cement mortar having excellent thermal conductivity is manufactured, and the cement mortar is used as a floor finishing layer. Can be applied to the floor heating structure. Therefore, it is possible to implement a floor heating structure with excellent thermal conductivity at a low cost, it is possible to reduce the length of the hot water pipe.

1 is a cross-sectional view of main parts showing a floor heating structure according to an embodiment of the present invention.
Figure 2 is a flow chart illustrating a construction method of the floor heating structure of the present invention.
3 is a graph showing the thermal conductivity of the cement mortar test specimen and the general cement mortar for the floor heating structure according to the present invention.
Figure 4 is a graph showing the thermal conductivity improvement rate of the cement mortar test specimens of the present invention compared to the general cement mortar.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the floor heating structure and the construction method using the thermally conductive cement mortar according to the present invention.

Referring to Figure 1, the floor heating structure of the present invention is installed on the concrete slab 11 of the building in order to form a bottom surface and the insulation layer 12 and light-weight foam concrete layer 13, and the light-weight foam concrete layer The hot water pipe 20 to be installed on the (13) and the hot water pipe 20 includes a cement mortar layer 30 that is poured on the upper surface of the lightweight foamed concrete layer 13 to be embedded. The flooring material 40 is constructed on the cement mortar layer 30.

Although the hot water pipe 20 is illustrated as being installed on the heat insulating material layer 12 and the light-weight foam concrete layer 13, the hot water pipe 20 is installed directly on the concrete slab 11 or the concrete slab ( 11) may be constructed on any other structure constructed on it.

The cement mortar layer 30 is constructed by placing on the bottom surface as a bottom finishing layer, the cement mortar layer 30 is any one of carbon nanotubes and graphene mixed in cement and sand, or carbon nano It is constructed by cement mortar made by mixing the tube and graphene together with cement and sand, and has excellent thermal conductivity.

More specifically, the cement mortar layer 30 mixes cement and sand in a weight ratio of 1: 1 to 3, water is 44 to 66% by weight based on cement weight, and silica fume is based on cement weight 10 ~ 20% by weight, carbon nanotubes or graphene, or 0.1 to 1.0% by weight of carbon nanotubes and graphene, and 0.005 to 0.01% by weight of cement (preferably 0.008% by weight) of cement It is made by mixing.

When the carbon nanotubes and graphene are mixed together, the carbon nanotubes and graphene are preferably mixed in a weight ratio of 1: 1.

Carbon nanotubes (CNTs) are small sized nanoparticles in the form of tubes, and are used in various fields based on their unique structural, chemical, mechanical and electrical properties due to the strong chemical bond called sp2. The carbon nanotubes may be used in various kinds, but it is preferable to use single-wall carbon nanotubes.

The graphene (graphene) is one of the allotrope of carbon is composed of a two-dimensional structure of one atom thick carbon atoms are each connected by sp2 bond, the benzene carbon ring forms a honeycomb crystal structure.

The carbon nanotubes and graphene have a very good thermal conductivity compared to other metal materials as can be seen through Table 1 below. In other words, carbon nanotubes and graphene have a thermal conductivity of about 7 to 10 times higher than silver and copper, about 15 to 30 times higher than aluminum, about 30 to 60 times higher than brass, and about 40 to 70 times higher than nickel and iron. have. These properties show the possibility that carbon nanotubes and graphene can act as effective heat spreaders. Therefore, it can be seen that the cement mortar layer 30 has very excellent thermal conductivity due to mixing of the carbon nanotubes and / or graphene.

material Thermal Conductivity W / (mK) Single Wall Carbon Nanotubes (SWNT) To 6000 Multi-walled Carbon Nanotubes (MWNT) To 3000 Graphene 5000 silver 429 Copper 400 aluminum 205 Brass 109 nickel 91 iron 80

The silica fume is a nanomaterial having a small particle size, such as carbon nanotubes of 10 ~ 500 nm serves to physically disperse the carbon nanotubes in cement. Silica fume mixed in the cement mortar layer 30 is preferably 10 to 20% by weight of the cement.

Next, a method of constructing the floor heating structure of the present invention as described above will be described with reference to FIG. 2.

First, the hot water pipe 20 is constructed on the floor of the building (step S1). And mixing the cement, sand, and silica fume for dry setting for a predetermined time (S2), and mixing carbon nanotube or graphene, or carbon nanotube and graphene in the mixture of cement, sand, and silica fume. Drying the beam for a time (S3), and the superfluiding agent is added to the mixture of water and stirred for a set time (step S4) to prepare a cement mortar.

Subsequently, the cement mortar prepared as described above is poured and plastered to fill the hot water pipe 20 (step S5), and then on the cement mortar layer 30 (see FIG. 1) formed by curing the cement mortar. The flooring material 40 (refer FIG. 1) is constructed (step S6).

The mixing ratio of each material to be mixed in the cement mortar manufacturing step (S2 ~ S4) is as described above. That is, cement and sand are mixed at a weight ratio of 1: 1 to 3, water is 44 to 66% based on cement weight, silica fume is 10 to 20% by weight based on cement weight, carbon nanotubes or graphene, or carbon Nanotubes and graphene are mixed with 0.1 to 1.0% by weight based on cement weight, and superfluidizing agent is mixed with 0.005 to 0.01% by weight based on cement weight to produce cement mortar. When the carbon nanotubes and graphene are mixed together, the carbon nanotubes and graphene are preferably mixed in the same weight ratio, that is, in a weight ratio of 1: 1.

Example 1

Table 2 below shows an embodiment of the mixing ratio of cement mortar for implementing the floor heating structure of the present invention.

Weight (g)
water

cement
Silica fume
sand
Superfluidizer
Carbon Nanotubes (CNT)
Graphene
(Graphene) CNT: Graphene
(1: 1) CNT Graphene 49.5 100 10 160 0.008 0.3 0.3 0.15 0.15

The cement cement mortar prepared in the above compounding ratio was poured into a mold of 15 × 15 × 5 cm, dried in a curing room for 1 day to prepare a test body, and then the test body was demolded from the mold and cured under water for 27 days. . On the 28th day, the specimens in aquatic curing were taken out and dried in an oven at 110 ± 5 ° C. for 3 days to make them completely dry, and then the thermal conductivity of the specimens in the completely dried state was measured.

In FIG. 3, reference mortar is a general cement mortar in which carbon nanotubes and graphene are not mixed. As shown in Figure 3, the general cement mortar showed a thermal conductivity of 0.43 (W / mk), 0.64 (W / mk) when only graphene is mixed, 0.79 (when only carbon nanotubes (CNT) are mixed W / mk), carbon nanotubes, and graphene were mixed together to show thermal conductivity of 0.82 (W / mk), respectively.

4 shows the thermal conductivity improvement rate of graphene mixed cement mortar, carbon nanotube mixed cement mortar, carbon nanotubes and graphene mixed cement mortar compared to general cement mortar.

As can be seen through Figure 4, when graphene is mixed about 49% compared to the general cement mortar, about 84% when carbon nanotubes are mixed, about 91% when graphene and carbon nanotubes are mixed together The thermal conductivity improvement effect of can be obtained.

As described above, according to the present invention, since the floor heating structure can be implemented using cement mortar having excellent thermal conductivity by mixing carbon nanotubes and / or graphene into cement, it is possible to obtain improved heat conduction performance. Accordingly, the thermal efficiency can be improved and the length of the hot water pipe can be reduced.

Although the present invention has been described in detail with reference to the embodiments, those skilled in the art to which the present invention pertains will be capable of various substitutions, additions, and modifications without departing from the technical spirit described above. It is to be understood that such modified embodiments are also within the protection scope of the present invention as defined by the appended claims.

11: concrete slab 12: insulation layer
13: light weight bubble concrete layer 20: hot water pipe
30: cement mortar layer 40: flooring

Claims (8)

Hot water pipe 20 is constructed on the bottom surface;
The hot water pipe 20 is placed on the bottom surface to be embedded, and includes a cement mortar layer 30 made by mixing carbon nanotubes, graphene, silica fume, superfluiding agent with cement and sand,
The cement mortar layer 30 is a mixture of cement and sand in a weight ratio of 1: 1 to 3, water is 44 ~ 66% by weight based on the cement weight, silica fume 10 ~ 20% by weight based on the cement weight, carbon nano Tube and graphene is 0.1 ~ 1.0% by weight based on cement weight, superfluidizer is mixed in 0.005 ~ 0.01% by weight based on cement weight, carbon nanotubes and graphene is mixed in a weight ratio of 1: 1 floor heating structure. delete delete delete delete (a) installing the hot water pipe 20 on the bottom surface;
(b) mixing the cement with sand and silica fume to dry the beam for a set time;
(c) incorporating carbon nanotubes or graphene, or carbon nanotubes and graphene into the mixture of cement, sand, and silica fume, and performing a dry beam for a predetermined time;
(d) adding a superfluidizing agent and water to the mixture and stirring the mixture for a set time to produce cement mortar;
(e) embedding the cement mortar on the bottom surface to bury the hot water pipe 20;
When preparing the cement mortar by performing the steps (b) to (d), cement and sand are mixed at a weight ratio of 1: 1 to 3, water is 44 to 66% by weight based on the weight of cement, and silica fume is 10 to 20% by weight of cement, carbon nanotubes and graphene are mixed 0.1 to 1.0% by weight of cement, superfluidizing agent is 0.005 to 0.01% by weight of cement, carbon nanotubes and graphene 1: Construction method of a floor heating structure characterized in that the cement mortar is mixed by mixing in a weight ratio of 1.
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