CN101481237B - Preparation of phase change heat storing heat preserving porous building block - Google Patents

Abstract

The invention discloses a preparation method of a phase-change heat storage and heat-preservation porous block. The method uses cement, fly ash, sand, stone powder, water, rice husk and composite phase change materials as raw materials, and is made into various blocks through a block forming machine. A standard block. By adjusting the ratio of raw materials, heat storage and heat preservation blocks with a bulk density of 800-1500kg/m ³ and a compressive strength of 3.2-6.4MPa can be obtained.

Description

Preparation method of a phase change heat storage and heat preservation porous block

technical field

The invention relates to the preparation of a novel building block, in particular to a preparation method of a phase change heat storage and heat preservation porous building block.

Background technique

At present, ordinary sintered bricks are mainly used in solar greenhouses, and the thermal insulation effect is poor; at the same time, due to the shortcomings of sintered bricks, such as large land occupation and high energy consumption, the country has issued a document to ban them all in 2010. Therefore, hollow blocks have become the next generation. main wall material.

At present, hollow blocks are widely used, especially thermal insulation blocks. There have been many patent applications for thermal insulation blocks in my country, for example, the Chinese patent application (application number: 200710190670.4, publication date: April 30, 2008), which is a composite of slurry, thermal insulation aggregates, and thermal insulation fillers. A self-insulating wall block with excellent performance is thus obtained. The block has the advantages of high compressive strength of more than 10MPa, thermal conductivity of less than 0.020W/m.K, excellent frost resistance and impermeability, small shrinkage, and convenient construction. High-strength self-insulating wall blocks that can be used directly as exterior walls. As another example, Chinese patent (200720039441.8, publication date: January 2, 2008) discloses a self-insulating block, which includes a block with holes and fillers in the holes, and is characterized in that it is perpendicular to the block. The masonry surface is provided with holes; one of the holes is filled with thermal insulation material, and the hole is located between the hollow hole and the side wall of the block, or is located between the hollow holes; or two of the holes are filled with thermal insulation material, the hole is The two holes are respectively located between the hollow hole and the side wall of the block, or one hole is located between the hollow holes and the other hole is located between the hollow hole and the side wall of the block. This application mainly achieves the purpose of heat preservation through the block with holes and the filler in the holes.

With the development of science and technology, thermal insulation materials and thermal insulation walls are also constantly improving. Many buildings have also adopted corresponding thermal insulation materials to reduce energy consumption of buildings. According to the data retrieval conducted by the applicant, there is no such Blocks with heat storage and heat preservation properties are used for production. If heat preservation materials can be combined with traditional blocks to produce a block with heat storage and heat preservation properties, the blocks can control indoor temperature fluctuations in buildings. It will be of great significance to the development of blocks.

Contents of the invention

Aiming at the current problem that blocks only keep heat but not store heat, the purpose of the present invention is to provide a method for preparing a phase-change heat-storage and heat-preservation porous block.

In order to realize above-mentioned task, the present invention adopts following technical solution:

A method for preparing a phase change heat storage and heat preservation porous block is characterized in that it specifically includes the following steps:

1) First, n-butyl stearate and paraffin are melted and mixed in a weight ratio of 4:6 to 5:5 to make a composite phase change material;

2) Then mix the rice husk with the water content lower than 3% and the composite phase-change material in a weight ratio of 1:1 to 1:2, heat and stir, so that the melted composite phase-change material and the rice husk are evenly mixed to form Composite phase change lightweight aggregate;

3) Mix the composite phase-change lightweight aggregate with cement, fly ash, fine sand, stone powder and water in an appropriate proportion, put it into a mixer and stir evenly, and then make a standard block through a block forming machine.

The raw materials of the phase-change heat-storage and heat-preservation porous block prepared by the present invention are simple and easy to obtain, and the thermal conductivity can be obtained at 0.3-0.9W/(m×℃) through different mixing ratios and different mold models of the block forming machine. Various types of hollow blocks with a heat storage coefficient of 15.6-25.5kJ/kg, a bulk density of 800-1500kg/m ³ and a compressive strength of 3.2-6.4MPa.

Description of drawings

Fig. 1 is a schematic diagram of a standard porous block with a specification of 240 mm * 115 mm * 90 mm prepared by the method of the present invention, and the porosity of the block is 30%.

Below in conjunction with embodiment the present invention is described in further detail.

Detailed ways

There are many problems in the effective combination of phase change materials and building materials. One of the main reasons is that when the prepared composite phase change materials are combined with building materials, there will be some leakage, which will lead to the strength of the prepared concrete blocks. and other performance degradation, this is a problem that must be addressed. In order to obtain the standard porous block prepared by the method of the present application, the applicant has carried out a large number of experiments since the beginning of 2008, continuously improved, selected different carrier materials for experiments, and finally found out a formula suitable for preparing standard porous blocks.

Experimental example 1: Take clay, composite phase change material, cement, fly ash, lime, gypsum, expanded perlite and water to mix and stir to make a test block, wherein clay, composite phase change material, cement, fly ash, lime, gypsum , The mass ratio of expanded perlite to water is 12:12:15:40:5:3:10:15, and the thermal conductivity of the obtained test block is small, which is 0.586W/(m×℃), although it meets the design requirements, but The compressive strength of the blocks prepared is too low, only 1.2Mpa, which cannot meet the strength requirements of the north wall of the greenhouse; at the same time, the blocks prepared in this way, the composite phase change material will have extravasation at a temperature of about 50°C .

Experimental Example 2: Mix clay and phase change material first, and let the clay be the carrier of the composite phase change material. Add cement, fly ash, lime, gypsum, sand and water and stir to make a test block, wherein the mass ratio of clay, composite phase change material, cement, fly ash, lime, gypsum, sand and water is 1:2:4: 4:1:1:7:2, the thermal conductivity of the obtained test block is 0.730W/(m×℃), but the compressive strength is 1.6MPa, which is relatively low, and cannot meet the strength requirements of the north wall of the greenhouse. The volume density is 1250kg. /m ³ ; and extravasation occurs at around 70°C.

Experimental Example 3: Considering that rice husk is a kind of waste in agricultural production, and it is a kind of porous material with good adsorption effect, so rice husk is used as the carrier of composite phase change material to make phase change aggregate. Mix rice husk and composite phase change material first, then mix with cement, fly ash, lime, gypsum, slag and water to make a test block, wherein rice husk, composite phase change material, cement, fly ash, lime, gypsum, The mass ratio of slag to water is 1:2:4:4:1:1:5:2, and the compressive strength of the obtained test block is also low, only 2.7MPa, the bulk density is 1050kg/m ³ , and the thermal conductivity is 0.790W/ (m×°C), and there is no extravasation when heated at high temperature (110°C).

Experimental example 4: Use rice husk as the carrier of phase change material, mix it with composite phase change material to make phase change aggregate, add cement, fly ash, lime, gypsum, stone powder and water to make test block, in which clay, The mass ratio of composite phase change material, cement, fly ash, lime, gypsum, stone powder and water is 1:2:4:4:1:1:5:2. The strength requirement of the single-layer structure of the greenhouse is that the thermal conductivity is 0.799W/(m×℃), and there is no extravasation when heated at high temperature (110℃).

After the above-mentioned multiple experiments, the raw materials of the formula of the block are finally determined to be rice husk, composite phase change material, cement, fly ash, fine sand, stone powder and water, and the water content of rice husk is required to be less than 3%.

Preparation Example 1: Melt and mix paraffin and n-butyl stearate according to the weight ratio of 6:4 to make a composite phase change material; then make the composite phase change material and rice husk according to the weight ratio of 1:1 Mix evenly, heat and stir to make the melted composite phase change material and rice husk mix evenly, then place it at room temperature to make a composite phase change lightweight aggregate, mix the above composite phase change lightweight aggregate with cement, fly ash, Fine sand, stone powder, and water are mixed evenly in the mixer according to the weight ratio of 1:12:4:6:8:4, and the standard hollow block is made by a block forming machine.

The hollow block obtained according to the preparation method of this example is shown in Figure 1. It has been tested and proved that its compressive strength is 5.5MPa, its bulk density is 1200kg/m ³ , and its thermal conductivity is 0.811W/(m×℃). The thermal coefficient is 15.6kJ/kg.

Preparation Example 2: Paraffin wax and n-butyl stearate were melted and mixed uniformly in a weight ratio of 6:4 to make a composite phase change material; then the phase change material was mixed with rice husk in a weight ratio of 2:1 Evenly, heat and stir to mix the melted composite phase change material and rice husk evenly, and then place it at room temperature to make a composite phase change lightweight aggregate; mix the above composite phase change lightweight aggregate with cement, fly ash, fine sand, The stone powder and water are mixed evenly in the mixer according to the weight ratio of 1:6:2:3:4:2, and the standard hollow block is made by a block forming machine.

The hollow block obtained according to the preparation method of this example is shown in Figure 1. It has been tested and proved that its compressive strength is 3.4MPa, its bulk density is 1443kg/m ³ , and its thermal conductivity is 0.703W/(m×℃). The thermal coefficient is 25.5kJ/kg.

Preparation Example 3: Paraffin wax and n-butyl stearate were melted and mixed uniformly according to a weight ratio of 5:5 to make a phase change material; then the phase change material and rice husk were mixed uniformly according to a weight ratio of 1:1, and heated Stir to mix the melted composite phase change material and rice husk evenly, place at room temperature to make a composite phase change lightweight aggregate; mix the above composite phase change lightweight aggregate with cement, fly ash, fine sand, stone powder, and water according to The weight ratio of 1:6:2:3:4:2 is mixed evenly in the mixer, and the hollow block is made by a block forming machine.

The hollow block obtained according to the preparation method of this example is shown in Figure 1. It has been tested and proved that its compressive strength is 4.6MPa, its bulk density is 975kg/m ³ , and its thermal conductivity is 0.792W/(m×℃). The thermal coefficient is 21.34kJ/kg.

The above are the preferred embodiments of the present invention, the present invention is not limited to these embodiments, of course, various types of hollow blocks can also be made through different mixing ratios and different mold models of the block forming machine.

It should be further pointed out that, based on the content disclosed in the present invention, those skilled in the art should realize that without departing from the technical features and scope of the present invention, all additions and replacements made to the technical features belong to the scope of the present invention. protected range.

Claims (2)

1. A preparation method of a phase change heat storage and heat preservation porous building block, characterized in that it specifically comprises the following steps: 1) First n-butyl stearate and paraffin are melted and mixed in a weight ratio of 4:6 to 5:5; a composite phase change material is made; 2) Then mix the rice husk with the water content lower than 3% and the composite phase-change material in a weight ratio of 1:1 to 1:2, heat and stir, so that the melted composite phase-change material and the rice husk are evenly mixed to form Composite phase change lightweight aggregate; 3) Mix the composite phase-change lightweight aggregate with cement, fly ash, fine sand, stone powder and water in an appropriate proportion, put it into a mixer and stir evenly, and then make a standard block through a block forming machine. 2. The method according to claim 1, characterized in that: the cement is 32.5# or 42.5# ordinary Portland cement.

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