KR101090526B1 - Motar with improved thermal storage performance comprising phase change materials - Google Patents

Abstract

PURPOSE: A mortar composition with an improved heat storing performance by including a phase change material is provided to reduce energy consumption and carbon dioxide by adjusting the mixing amount and the melting point of a paraffin-based phase change material. CONSTITUTION: A mortar composition includes cement, sand, water, and paraffin-based phase change material. The paraffin-based phase change material is a C13 to C24 paraffin-based material. The melting point of the paraffin-based phase change material is between 23 and 32 degrees Celsius. The density, the thermal conductivity, the heat storing capacity, and the specific heat capacity of the paraffin-based phase change material are between 0.6 and 0.75 kg/l, between 4 and 4.5 kcal/hm°C, between 110 and 180 kJ/kg, and between 1.0 and 2.0 kJ/(KgxK). A method for manufacturing the mortar composition includes the paraffin-based phase change material and cement mixing process and a sand and water introducing process with respect to the mixture.

Description

Mortar composition with improved thermal storage performance including phase change materials

The present invention relates to a mortar composition comprising a phase change material, and more particularly, to a mortar composition having improved heat storage performance, including a paraffinic phase change material.

In recent years, the world has put the highest priority on preventing global warming due to greenhouse gases (GHG) such as carbon dioxide (CO ₂ ) and methane (CH ₄ ) emitted by human activities. Accordingly, we have been making continuous efforts to date, including adopting the 1992 United Nations Framework Convention On Climate Change (UNFCCC) as a global response plan, and establishing our own response strategies and policies. Since the 1997 Kyoto Protocol, which was proposed as a concrete implementation plan of the climate change convention, international interest in greenhouse gas reduction has been heightened. In particular, the impact of CO ₂ among greenhouse gases, which are the major causes of climate change, Since it is found to be much higher than other factors at 55% or more, the technology for reducing greenhouse gas emissions due to CO ₂ reduction is important.

The construction sector accounts for about 35% of the domestic CO ₂ emissions by industry. It also emits CO ₂ consistently throughout the building's life cycle (LCC), from building construction, operation, maintenance, demolition to decommissioning, accounting for more than 70% of the building's operational maintenance phase. Most of the CO ₂ generated in buildings comes from energy use. The energy load of a building means the amount of heat required to continuously maintain the indoor comfort environment during the cooling and heating of the building. An air conditioner, a freezer, a boiler, etc., are used as a means for maintaining this. Therefore, the energy reduction by the efficient use of such a system can be a very effective part to automatically reduce CO ₂ .

In the construction materials sector, efforts are being made to develop building materials, materials, and construction methods for energy reduction and CO ₂ reduction based on the efficient facility system, and many new technologies based on the results are reaching the practical use stage. .

Among these techniques, materials and techniques according to heat storage can be very effective and breakthrough technologies. Therefore, in the field of materials, Phase Change Materials (PCM), an innovative thermoregulator that functions as a heat storage and temperature control device, has been discovered and research efforts have been made gradually since the late 1980's, but the level is still small in Korea. . Looking at the development trend of the energy-saving technology by the current PCM, most of the technologies due to external structural elements such as building exterior materials. Most of these technologies are found to have a number of problems in terms of construction and maintenance, and the economics are also a problem.

Accordingly, the first problem to be solved by the present invention is to provide a mortar composition that can induce energy reduction and reduction of carbon dioxide emissions according to the effective operation of the air conditioner using the cold / hot heat storage performance, including a phase change material. It is.

The second problem to be solved by the present invention is to provide a method for preparing a mortar composition in which the formulation order is specified in order to control the crack occurring after the mortar hardening due to the volume expansion of the phase change material in the production of the mortar composition.

The third problem to be solved by the present invention is to provide an energy and carbon dioxide reduction building material using a mortar composition containing the phase change material.

The present invention to achieve the first object,

Cement, sand, water and paraffin-based phase change material, the phase change material comprises a phase change material characterized in that 3-35% by weight based on the weight of cement in the total mortar composition, the melting point is 23-32 ℃ It provides a mortar composition.

According to an embodiment of the present invention, the mortar composition may have a compressive strength of 16-33 MPa and a flowability of 120-160 mm.

According to one embodiment of the invention, the phase change material may be included in the mortar composition in the form of spherical microencapsulated.

According to an embodiment of the present invention, the phase change material is a paraffinic material having 13 to 24 carbon atoms, has a density of 0.65-0.75 kg / l, a thermal conductivity of 4-4.5 kcal / hm ° C., and an average particle size of 150-250 μm. Heat storage capacity 110-180 kJ / kg, specific heat capacity 1.0-2.0 kJ / (kg × K).

According to another aspect of the present invention,

After the paraffin-based phase change material and cement are mixed in a dry beam, there is provided a method for producing a mortar composition prepared in a compounding sequence in which sand and water are added to the mixture of the phase change material and cement.

In order to achieve the third object,

As a finishing plastering material of a building using a mortar composition containing the phase change material, or as a floor mortar mortar provides energy and carbon dioxide reduction heat storage material generated according to the effective operation of the heater.

Mortar composition comprising a phase change material according to the present invention is confirmed by the experiments in the thermal performance excellent cold and hot heat storage performance, and confirms the energy reduction effect when applied to the mortar mortar, cold and heat storage performance of the PCM mortar according to the present invention When applied to buildings, carbon dioxide reduction and energy reduction can be achieved by efficient use of air conditioners.

1 is a schematic diagram showing a cross section of a thermal performance test method for a PCM mortar according to the present invention using a chamber.
FIG. 2 is an image showing the degree of PCM distribution in the mortar according to the amount of PCM incorporation, and it is possible to confirm an even distribution of spherical PCM particles encapsulated in FIGS. 2B to 2F.
Figure 3 is a graph of the heat transfer performance of the mortar mixed with PCM having a melting point of 23 ℃.
Figure 4 is a graph of the heat transfer performance of the mortar incorporating PCM having a melting point of 23 ℃.
5 is a graph illustrating the heat transfer performance of the mortar incorporating PCM having a melting point of 31 ° C.
6 is a graph illustrating heat transfer performance of mortar mixed with PCM having a melting point of 31 ° C.
7 is a graph illustrating the heat transfer performance of mortar incorporating PCM having a melting point of 28 ° C.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

The present invention incorporates PCM (Phase Change Materials) having excellent latent heat performance into mortar as one of the measures to prevent energy depletion and carbon dioxide (CO ₂ ) emission, which is being accelerated in recent years, the proper amount of PCM and mortar properties, The optimum melting point of PCM for the performance and floor heating and cooling applications was derived, and the heat transfer and latent heat performance was confirmed through the thermal performance test.

Therefore, when the mortar composition including the PCM according to the present invention is applied to the building can be expected to reduce the heating and cooling energy, it can be expected to reduce the energy by the on-off operation control of the heating and cooling in the building and thereby CO ₂ reduction.

The present invention includes cement, sand, water and paraffinic phase change material, wherein the phase change material is 3-35 wt% based on cement in the total mortar composition, and characterized in that the melting point is 23-32 ℃. In particular, the mortar composition has a compressive strength of 16-33 MPa and a flowability of 120-160 mm.

In order to evaluate the mortar applicability of the PCM mixed mortar composition according to the present invention, a test body was prepared and evaluated in a manner similar to that of actual floor heating system construction. Box-shaped test specimens were prepared, and after heating the concrete, flooring was installed, the heating wire was installed on the floor to control the temperature from 0 ° C to 60 ° C, followed by OPC (General Portland Cement) and PCM (Phase Change Material according to the Invention) 3 Mortars incorporating%, 5%, 10%, 20%, and 30% were poured each 40 mm. After sufficient period of curing, the inner wall was finished with insulation material, and it was manufactured to reduce the heat loss due to heat leakage to the outside of the test specimen during the experiment. A temperature sensor was attached to the center of the box and the center of the bottom surface to measure the atmosphere and surface temperature inside the box.

The fabricated specimens were placed in a chamber with temperature control from -20 ° C to 100 ° C so that the temperature inside the chamber could be set similar to winter temperature (0 ~ -5 ° C). After setting the internal temperature, it was possible to set the same bottom temperature of the test body by using a temperature controller mounted on the test body.

Hereinafter, the present invention will be described in more detail with reference to preferred examples. It will be apparent, however, to those skilled in the art that these embodiments are for further explanation of the present invention and that the scope of the present invention is not limited thereby.

Example

In the present invention, the physical properties and thermal performance of the mortar incorporating PCM was confirmed, and the energy reduction effect was confirmed when the PCM mortar according to the present invention was applied to a building structure.

Mortar experiments were carried out in accordance with KS L ISO 679, the cement used in the present invention used the one kind of ordinary portland cement of Table 1 below. Sand was used as standard yarn specified in KS L ISO 679.

Chemical composition Properties MgO SO ₃ ignition loss fineness
(㎡ / g) stability
(%) density
(g / cm3) 5.0 or more 3.5 or less 3.0 2800 0.8 3.15

In addition, Table 2 shows the performance of the PCM used in the present invention, the PCM Melting point 23 ℃, 28 ℃, 31 ℃ two conditions for the selection of the melting point in consideration of the room comfort temperature for efficient use of PCM grafting In consideration of the experiment. In addition, according to the volume expansion characteristics of paraffin-based PCM, the volume distribution is reduced by reducing the concentration of particles by applying a compounding sequence in which sand and water are added after mixing cement and PCM. Minimization was minimized.

Furtherance Properties SiO ₂ , Paraffin Bulk density
Melting point (PCM)
Average particle size
Heat storage capacity
Volume expansion
Specific heat capacity
Flash point (PCM)
Operating temperature 0.6-0.75 kg / l
23, 28, 31 ℃
150-250 μm
110-180 kJ / kg
none
1.0-2.0 kJ / (kg × K)
222 ℃
max. 90 ℃

In addition, PCM Melting point 23, PCM mortar blending conditions tested at 31 ℃ are shown in Table 3 below.

cement
(kg) water
(kg) sand
(kg) PCM (kg) Melting point (23, 31 ℃) 0% 10% 20% 30% 2 One One - 0.2 0.4 0.6

[Table 4] shows the compounding table in which PCM was substituted by the weight ratio of cement, and after compounding, it was poured into a 100 mm × 115 mm × 20 mm test body and a 40 mm × 40 mm × 160 mm standard mold, respectively. One day curing was carried out.

division Volume of OPC (kg) Amount of PMC (kg) PCM Melting Point Example 1 PCM 3% 1.94 0.06 23 ℃ Example 2 PCM 5% 1.9 0.1 Example 3 PCM 10% 1.8 0.2 Example 4 PCM 20% 1.6 0.4 Example 5 PCM 30% 1.4 0.6 Example 6 PCM 10% 1.8 0.2 31 ℃ Example 7 PCM 20% 1.6 0.4 Example 8 PCM 30% 1.4 0.6 Comparative Example 1 PCM 100% 2.0 0 - Comparative Example 2 Isopink - - Comparative Example 3 Gypsum board - - Comparative Example 4 Styrofoam - -

Mortar test specimens by PCM content after 28 days of curing and the three insulators used in the experiments were fixed to the lattice-shaped specimens for comparison under the same conditions. In addition, more accurate experiments were induced by inserting insulating fibers between each specimen to minimize heat transfer between the specimens.

As shown in Figure 1 by fixing the test specimen to the chamber inlet and by attaching a temperature sensor to the inside and outside surfaces of the test, the change in each test inside and outside for the various heating temperature was measured. The experiment time for each temperature was based on the time when the temperature change of the general OPC test specimen having higher thermal conductivity was stopped compared to PCM mortar. 1 is a schematic view showing the cross-sectional shape of the thermal experimental method using a chamber for the PCM mortar according to the present invention. The heat was transferred from the inside of the chamber to transfer heat to the test body, and the overall heat was set to be distributed evenly throughout the test body.

Evaluation example

(1) Figure 2 is an image taken to confirm the degree of PCM distribution in the mortar according to the amount of PCM incorporation. An even distribution of encapsulated spherical PCM particles can be seen.

(2) [Table 5] shows the results of experiments on the flowability and compressive strength of mortar according to the amount of PCM incorporation, and both experiments showed a tendency that the higher the amount of PCM added, the lower the value. As a result, it was confirmed that it had a relatively uniform width and decreased. Based on the above results, it is necessary to correct the fluidity and strength for use as a building structure.

division OPC PCM3% PCM5% PCM10% PCM20% PCM30% Compressive strength (MPa) Flow (mm)

(3) Table 6 shows the heating temperature history using the chamber in the thermal performance test of PCM mortar. In order to select the melting point considering the most efficient and effective use of PCM mortar cooling and heating system, PCM with two melting points of 23 and 31 ℃ was mixed and applied to mortar.

division Melting Point (℃) Heating temperature (℃) A 23 0 → 55 B 23 30 → 0 C 31 0 → 40 D 31 40 → 0

Figure 3 is a value of the heat transfer performance of the mortar mixed with PCM having a melting point of 23 ℃. The change of the outer surface temperature of each test body was measured as the conditions heated in 360 degree heating temperature history of A of Table 6. 3a is compared with OPC and other insulation materials according to the amount of PCM incorporation, PCM 30% showed the best insulation performance. This is a result of confirming the basic heat storage performance of the PCM, showing the excellent cold heat storage performance. 3b is a secondary graph of FIG. 3a comparing the PCM 30% with the best performance, OPC, and other heat insulators, and the PCM 30% showed better heat storage performance than other materials.

(4) Figure 4 is a result of experiments on the latent heat performance of the mortar mixed with PCM having a melting point of 23 ℃. The heating temperature history of B was performed under conditions. Incorporation of 3% and 5% less thermal performance was excluded. In the graph of Figure 4a it can be seen that mortar incorporating PCM 30% has superior latent heat performance compared to other thermal insulation materials, OPC, the second graph of Figure 4b used in the experiment with excellent latent heat performance of PCM 30% It was found that the effect was greatly exerted from the vicinity of the PCM melting point of 23 ° C to 20 ° C. In addition, it was confirmed that the function is quickly lost after the phase change, it can be seen that the phase change section is about ± 5 ℃ based on the melting point.

(5) Figure 5 is a result of conducting a heat transfer experiment of PCM having a melting point of 31 ℃ with a heating temperature history as shown in Table 6 C. It was found that 30% of PCM showed the best performance in cold storage heat, and it was found that it showed a relative performance of about 5 ℃ or more compared to OPC. In addition, the secondary graph of Figure 5b confirmed that over time, the heat storage function is lost and similar to other materials. Therefore, if the cooling air on-off control using the cooling heat storage performance it is determined that efficient energy saving is possible.

6 is a result of the latent heat experiment of PCM having a melting point of 31 ° C. with a heating temperature history as shown in Table 6 below. In Figure 6a below it was confirmed that the phase change phenomenon in the range of about 31 ± 5 ℃ melting point exhibits latent heat performance. In addition, in the second graph of FIG. 6B, PCM 30% may show a latent heat effect with a phase change in the range of 31 ± 5 ° C. FIG. Therefore, as a result of the experiment on the two melting points, the mortar mixed with PCM of 31 melting point satisfies both the cooling and heating heat storage performance, and the cooling and heating room comfort temperature (24-28 ℃) is efficiently It seems that it can be maintained. In addition, on the basis of the results shown in the experiment, compared with OPC, the average difference of about 5 ℃ or more and more than 90 minutes within the comfort temperature, which is due to the energy reduction and the CO ₂ It can work very effectively on abatement.

As such, the even particle distribution was confirmed according to the mortar incorporation of micro encapsulated PCM in the SEM image. It was found that the effect of maintaining the temperature more than 90 minutes.

In addition, as a result of judging the temperature range of cold and hot heat storage zones according to PCM melting point 23 ℃, 28 ℃, 31 ℃ through experiments, it can be seen that the PCM melting point for effective maintenance of indoor comfort temperature (24-28 ℃) is 31 ℃ there was.

Therefore, it was confirmed that the energy reduction possibility according to the on-off control of the building air conditioner using the cold and hot heat storage performance of the PCM mortar according to the present invention compared to the OPC.

Claims (10)

Including cement, sand, water and paraffinic phase change materials,
The paraffinic phase change material is a paraffinic material having 13 to 24 carbon atoms, a melting point of 23-32 ° C., a density of 0.6-0.75 kg / l, a thermal conductivity of 4-4.5 kcal / hm ° C., and a heat storage capacity of 110-180 kJ / kg. And specific heat capacity of 1.0-2.0 kJ / (kg × K),
The paraffin-based phase change material is a mortar composition, characterized in that 3-35% by weight based on the cement weight of the total mortar composition. The method of claim 1,
The paraffinic phase change material is a mortar composition comprising a phase change material, characterized in that the average particle size of 150-250 ㎛. The method of claim 1,
The mortar composition is a mortar composition comprising a phase change material, characterized in that the compressive strength is 16-33 MPa, the fluidity is 120-160 mm. The method of claim 1,
The phase change material is a mortar composition comprising a phase change material, characterized in that included in the mortar composition in the form of spherical micro-encapsulated. (a) mixing paraffin-based phase change material and cement in a dry beam; And
(b) injecting sand and water into the mixture of phase change material and cement;
The paraffinic phase change material is a paraffinic material having 13 to 24 carbon atoms, a melting point of 23-32 ° C., a density of 0.6-0.75 kg / l, a thermal conductivity of 4-4.5 kcal / hm ° C., and a heat storage capacity of 110-180 kJ / kg. And a specific heat capacity of 1.0-2.0 kJ / (kg × K). The method of claim 5, wherein
The paraffin-based phase change material is 3-35% by weight based on the weight of cement in the total mortar composition, a method for producing a mortar composition, characterized in that the spherical microencapsulated form. The method of claim 5, wherein
The paraffinic phase change material is a method for producing a mortar composition, characterized in that the average particle size of 150-250 ㎛. The method of claim 5, wherein
The mortar composition has a compressive strength of 16-33 MPa, the flow method of producing a mortar composition, characterized in that 120-160 mm. Energy and carbon dioxide reduction heat storage material prepared using a mortar composition comprising a phase change material according to claim 1. Energy and carbon dioxide reduced floor penetration mortar heat storage material prepared using a mortar composition comprising a phase change material according to claim 1.

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