CN104944819B - A kind of phase-change accumulation energy aggregate and preparation method thereof - Google Patents

Abstract

The invention provides a method for preparing phase-change energy storage aggregate by using autoclaved aerated concrete of abandoned buildings. The ratio by weight is: 10 parts of waste aerated concrete particles, 7-10 parts of phase-change materials, and polymer emulsion 1.7-2.7 parts, steel slag powder 4.5-5.5 parts, cement 1.2-1.8 parts, water 2-2.5 parts, building gypsum 1.5-2 parts, manganese slag powder 3-3.8 parts. The obtained phase change energy storage aggregate has high strength, good affinity with inorganic cementitious materials, the phase change material is not easy to leak, and is durable; it can be used to prepare mortar, concrete, and produce various building blocks or plates, etc.

Description

A kind of phase change energy storage aggregate and preparation method thereof

technical field

The invention relates to a method for preparing phase-change energy-storage aggregate by using waste autoclaved aerated concrete as the core support material. The obtained phase-change energy-storage aggregate is used to prepare mortar and concrete, and to produce various buildings Blocks or panels etc. .

Background technique

Phase change energy storage material is a kind of thermal functional material, which can store energy in the form of phase change potential, and realize the conversion of energy between different time periods. In recent years, problems such as the depletion of mineral energy and environmental pollution have become more and more prominent. Improving energy efficiency and developing renewable energy have become important issues facing mankind. Utilizing the latent heat of phase change materials (Phase ChangeMaterials (PCMs)) to store and utilize energy can help improve energy efficiency and develop renewable energy. It is a very active frontier research direction in the fields of energy science and material science in recent years. . Compared with sensible heat storage materials, phase change energy storage composite materials have the advantages of high energy storage density, small volume, constant temperature control, remarkable energy saving effect, wide selection range of phase change temperature, and easy control. , heating and air conditioning, power supply system optimization, medical engineering, military engineering, thermal storage buildings and extreme environment clothing and many other fields have broad prospects.

Especially in the field of construction, the use of phase change energy storage composite materials can not only significantly improve the heat storage capacity of buildings, but also help to lighten and thin the building structure, which has attractive application value. Some theoretical analysis and simulation studies have shown that the use of floors or ceilings with energy storage functions can greatly reduce building energy consumption and HVAC operating costs by storing cold (heat) at night and improving the indoor thermal comfort of buildings. and its load on social power. As we all know, our country is relatively short of electric energy, especially in some economically developed areas, the situation that the supply of electric energy is often in short supply in summer. In the total power load of the society, the air-conditioning load accounts for a large proportion. Therefore, if the power load of the air-conditioning can be reduced, it will have significant social significance.

At present, in the research of phase change energy storage materials, some studies melt the phase change energy storage materials and mix them with porous particles, and make the phase change energy storage materials penetrate into the porous particles under vacuum or non-vacuum conditions to form a phase change. Energy storage aggregate. For example, in the patent document "Phase Change Energy Storage Composite Materials for Construction and Its Preparation Method" CN1450141A, the porous material aggregates are made of expanded clay, expanded shale, expanded perlite, and expanded fly ash; the organic phase change materials are made of paraffin, stearin butyl ester. In the patent document "A Preparation Method of Porous Media Composite Phase Change Energy Storage Particles" CN103666380A, the porous media is expanded perlite, vitrified microbeads, diatomite, bentonite or graphite.

Autoclaved aerated concrete/blocks are widely used in modern buildings due to their light weight, porosity and good thermal insulation performance to improve the thermal insulation performance of buildings. Affected by the service life of the building and the development of urban architectural planning, the demolition of old urban buildings has produced a large amount of waste autoclaved aerated concrete (hereinafter referred to as waste aerated concrete), and its production will increase year by year. If a large amount of waste aerated concrete cannot be processed and digested in time, it will occupy a large amount of land, causing pollution to the atmosphere and water, and will cause great harm to society and the environment, as well as waste of resources. The invention uses waste aerated concrete as a support material to develop a durable phase change energy storage aggregate that is not easy to leak.

Contents of the invention

The invention provides a phase change energy storage aggregate prepared by using waste aerated concrete and a preparation method thereof.

The specific scheme of the phase change energy storage aggregate of the present invention is: a phase change energy storage aggregate, which is composed of a phase change material core and an encapsulation shell; Concrete particles; the encapsulation shell is a composite layer composed of polymer emulsion, steel slag powder, cement, building gypsum, and manganese slag powder; the proportion of the phase change energy storage aggregate is, by weight, waste aerated concrete 10 parts of particles, 7-10 parts of phase change material, 1.7-2.7 parts of polymer emulsion, 4.5-5.5 parts of steel slag powder, 1.2-1.8 parts of cement, 2-2.5 parts of water, 1.5-2 parts of building gypsum, 3 parts of manganese slag powder ~3.8 copies.

A method for preparing the phase change energy storage aggregate, the method comprises the following steps:

Step 1: Crushing the waste aerated concrete into particles with a particle size of 2-7mm;

Step 2: heating and melting the phase change material, adding 10 parts of the waste air-entrained concrete particles in the step 1, and absorbing for 2 hours under a vacuum of 0.06-0.08 MPa to make a core of the phase change material;

Step 3: The polymer emulsion, steel slag powder, cement and water are made into a mixed slurry according to the mass ratio (1.7-2.7): (4.5-5.5): (1.2-1.8): (2-2.5), the The polymer emulsion is white latex and/or sodium methyl siliconate; the construction gypsum and manganese slag powder are made into mixed powder according to the ratio of mass ratio (1.5-2): (3-3.8); The obtained core core of the phase change material is immersed in the mixed slurry for 4-8 seconds, and then wrapped with a layer of the mixed powder on its outside; after curing, the phase change energy storage aggregate is obtained.

The polymer emulsion is white latex and/or sodium methyl siliconate.

The particle diameter of the waste aerated concrete is 2-7mm.

The phase transition temperature of the phase change material is 25-36°C.

The specific surface area of the steel slag powder is 400-500m ² /kg.

The cement is any one in "Universal Cement" GB175-2007.

The specific surface area of the manganese slag powder is 450-550m ² /kg.

In the method for preparing the phase-change energy storage aggregate, a layer of the mixed powder can be wrapped on the outside of the phase-change material core by a roller or turntable process.

In the present invention, waste air-entrained concrete particles form a hydrophobic layer on its surface due to the adsorption of phase change materials. If white latex and/or sodium methyl siliconate emulsion are not added to the mixed slurry, the hydrophobic layer will It is difficult to absorb a water film on the layer, and it is difficult to form a thin and uniform inorganic material encapsulation shell outside the core of the phase change material. If the thickness of the packaging shell is uneven, the bearing capacity is uneven, and some of the packaging shells are easy to fall off, which will affect the strength of the phase change energy storage aggregate and cause leakage of the phase change material. Adding emulsions such as white latex and/or sodium methyl siliconate into the mixed slurry can solve the above problems well. In addition, white latex and sodium methyl siliconate emulsion have film-forming properties. After dehydration, a layer of polymer protective film can be formed to block the micropores of the inorganic packaging layer and play a role in strengthening the packaging of the phase change material of the core. making it harder to leak.

The beneficial effects of the present invention are:

The invention uses waste aerated concrete as the core support material to make phase-change energy storage aggregate, realizing the utilization of waste aerated concrete; wrapping a uniform polymer and inorganic material composite layer outside the phase-change material core to solve the problem The problem of easy leakage of phase change materials has been solved. The phase change energy storage aggregate has high strength and good phase change energy storage effect, and because the packaging material is an inorganic material, it is compatible with cementitious materials when it is used to prepare mortar and concrete and produce various building blocks or plates. Far superior to other porous materials such as expanded perlite and lightweight ceramsite.

Description of drawings

Figure 1 is the internal temperature change curve of the test box under different temperature environments, curve 1 is the temperature change curve inside the box without phase change energy storage aggregate, and curve 2 is the box with phase change energy storage aggregate Internal temperature change curve.

detailed description

Embodiment one

Put a sufficient amount of phase change material with a phase change temperature of 25.7°C (the weight ratio is liquid paraffin:paraffin wax=85:15, and the phase change enthalpy is 105.1J/g) into the container, and heat up to melt the phase change material; Add 10 parts of waste aerated concrete particles with a particle size of 2-7 mm, stir evenly, seal the container, and absorb for 2 hours under a vacuum of 0.06 MPa to make a phase change material core.

Sodium methyl siliconate emulsion, steel slag powder (specific surface area of 417m ² /kg), 32.5# ordinary Portland cement and water are prepared into a mixed slurry in a mass ratio of 2.7:5.5:1.2:2; construction gypsum and manganese slag powder (the specific surface area is 532m ² /kg) to make mixed powder according to the mass ratio of 1.5:3.8. Immerse the core of the phase change material in the mixed slurry for 4 seconds, take it out and wrap a layer of the mixed powder on the outside; keep it for 28 days naturally to obtain the phase change energy storage aggregate. After calculation, the specific material ratio of phase change energy storage aggregate: 10 parts of waste aerated concrete particles, 7.4 parts of phase change materials, 2.66 parts of sodium methyl siliconate emulsion, 5.42 parts of steel slag powder, 1.28 parts of cement, and 2.07 parts of water , 1.58 parts of construction gypsum, 3.74 parts of manganese slag powder.

Embodiment two

Put a sufficient amount of phase change material with a phase change temperature of 29.3°C (liquid paraffin:stearic acid=78:22 by weight, phase change enthalpy is 135.2J/g) into the container, heat up to melt the phase change material Add 10 parts of waste aerated concrete particles with a particle size of 2-7 mm, stir evenly, seal the container, and absorb for 2 hours under a vacuum of 0.08 MPa to make a phase change material core.

White latex, steel slag powder (specific surface area is 453m ² /kg), 32.5# fly ash portland cement and water are made into a mixed slurry at a mass ratio of 2.2:5:1.5:2.2; building gypsum and manganese Slag powder (with a specific surface area of 516m ² /kg) is made into a mixed powder with a mass ratio of 1.7:3.5. Immerse the core of the phase change material in the mixed slurry for 6 seconds, take it out, and then wrap a layer of the mixed powder on its outside; keep it for 28 days naturally to obtain the phase change energy storage aggregate. After calculation, the specific material ratio of phase change energy storage aggregate: 10 parts of waste aerated concrete particles, 9.6 parts of phase change materials, 2.13 parts of white latex, 4.85 parts of steel slag powder, 1.46 parts of cement, 2.13 parts of water, and 1.74 parts of building gypsum 3.58 parts, manganese slag powder.

Embodiment three

Put a sufficient amount of phase change material with a phase change temperature of 35.2°C (liquid paraffin: butyl stearate = 75:25 by weight, phase change enthalpy is 143.2J/g) into the container, and raise the temperature to make the phase change The material is melted; 10 parts of waste aerated concrete particles with a particle size of 2-7 mm are added, stirred evenly, the container is sealed, and adsorbed for 2 hours under a vacuum of 0.07 MPa to make a phase change material core.

Make a mixed slurry by using sodium methyl siliconate emulsion, white latex, steel slag powder (specific surface area of 485m ² /kg), 32.5# slag salt cement and water at a mass ratio of 1:0.7:4.5:1.8:2.5 ; Mix construction gypsum and manganese slag powder (with a specific surface area of 464m ² /kg) at a mass ratio of 2:3 to make a mixed powder. Immerse the core of the phase change material in the mixed slurry for 8 seconds, take it out and wrap a layer of the mixed powder on its outside; keep it for 28 days naturally to obtain the phase change energy storage aggregate. After calculation, the specific material ratio of phase change energy storage aggregate: 10 parts of waste aerated concrete particles, 8.9 parts of phase change materials, 1.09 parts of sodium methyl siliconate emulsion, 0.79 parts of white latex, 4.55 parts of steel slag powder, and 1.78 parts of cement 2.47 parts of water, 1.96 parts of construction gypsum, and 3.04 parts of manganese slag powder.

Phase-change box preparation: 1 part of phase-change energy storage aggregate (obtained from Example 3), 1 part of 32.5# slag salt cement, 2 parts of river sand, and 1.5 parts of water are prepared into phase-change thermal insulation mortar with a thickness of 20mm mortar board; after 28 days of normal temperature curing, the mortar board is spliced into a hollow box of 7cm×7cm×11cm, the seams are bonded with epoxy resin, and a temperature sensor is installed in the hollow part inside.

Comparison box preparation: 1 part of 32.5# slag salt cement, 2 parts of river sand, and 1.5 parts of water are prepared into ordinary mortar to make a mortar board with a thickness of 20mm; after the mortar board is cured at room temperature for 28 days, it is spliced into 7cm×7cm A hollow box of ×11cm, the seams are bonded with epoxy resin, and a temperature sensor is installed in the hollow part inside.

During the test, the room temperature and the internal temperature of both boxes were 27°C. First put the two boxes in a 38°C incubator, and measure the internal temperature of the boxes every 6 minutes; when the internal temperature of the two boxes reaches 38°C, take out the two boxes at the same time and place them in a room temperature environment of 27°C In the process, the internal temperature of the box was measured every 6 minutes, and the internal temperature change curve of the box under different temperature environments was obtained in Fig. 1 .

Claims (7)

1. a phase-change accumulation energy aggregate, it is characterised in that be made up of phase-change material nuclear core and package casing；Described phase-change material core Core is the useless air entrained concrete granule having adsorbed phase-change material；Described package casing be by polymer emulsion, steel-making slag powder, cement, The composite bed of plaster of Paris, manganese ground-slag composition；The proportioning of described phase-change accumulation energy aggregate, be by weight, useless air entrained concrete Grain 10 parts, phase-change material 7～10 parts, polymer emulsion 1.7～2.7 parts, steel-making slag powder 4.5～5.5 parts, cement 1.2～1.8 parts, Water 2～2.5 parts, plaster of Paris 1.5～2 parts, manganese ground-slag 3～3.8 parts；Described polymer emulsion is white glue with vinyl and/or methyl silicon Sodium alkoxide.

Phase-change accumulation energy aggregate the most according to claim 1, it is characterised in that described useless air entrained concrete grain diameter is 2 ～7mm.

Phase-change accumulation energy aggregate the most according to claim 1, it is characterised in that the phase transition temperature of described phase-change material be 25～ 36℃。

Phase-change accumulation energy aggregate the most according to claim 1, it is characterised in that the specific surface area of described steel-making slag powder be 400～ 500m²/kg。

Phase-change accumulation energy aggregate the most according to claim 1, it is characterised in that described cement is " general-purpose cement " GB175- Any one in 2007.

Phase-change accumulation energy aggregate the most according to claim 1, it is characterised in that the specific surface area of described manganese ground-slag be 450～ 550m²/kg。

7. prepare the method for phase-change accumulation energy aggregate described in claim 1 for one kind, it is characterised in that the method comprises the following steps:

Step one: useless air entrained concrete is broken into the granule that particle diameter is 2～7mm；

Step 2: phase-change material is heated up and melts, add the useless air entrained concrete granule in 10 parts of described steps one, 0.06～ Adsorb 2h under 0.08MPa vacuum, make phase-change material nuclear core；

Step 3: by polymer emulsion, steel-making slag powder, cement and water in mass ratio 1.7～2.7:4.5～5.5:1.2～1.8:2～ The ratio of 2.5 makes mixed slurry, and described polymer emulsion is white glue with vinyl and/or methyl silicon sodium alcoholate；By plaster of Paris, manganese ground-slag The ratio of in mass ratio 1.5～2:3～3.8 makes mixed powder；The phase-change material nuclear core obtained in described step 2 is immersed In described mixed slurry 4～8 seconds, outside it, after pulling out, wrap up one layer of described mixed powder again；After maintenance, obtain phase Become energy storage aggregate.