Phase change energy storage concrete wallboard and preparation method thereof

Abstract

The invention discloses a phase-change energy-storage concrete wallboard and a preparation method thereof, and belongs to the technical field of thermal insulation of outer walls of transformer substations, the phase-change energy-storage concrete wallboard comprises a foam concrete board with grooves on two sides, phase-change material cement mortar, two profiled steel sheets and two decorative boards, grooves in the two faces of the foam concrete plate are filled with the phase-change material cement mortar, the two profiled steel plates are fixed to the two faces of the foam concrete plate respectively to seal the phase-change material cement mortar, and the two decorative plates are fixed to the two profiled steel plates respectively. Through the innovative structural design, the leakage problem of a traditional phase change material is solved, and the building heat preservation and energy storage performance and the construction efficiency are remarkably improved. In addition, the phase change energy storage concrete wallboard provided by the invention has relatively good thermal insulation performance, the thermal insulation capability can be adjusted by improving the thickness of the wallboard in practical application, heat transfer caused by indoor and outdoor temperature difference can be slowed down due to the good thermal insulation performance, and the phase change energy storage concrete wallboard is suitable for various weather conditions.

Description

Technical Field

[0001] The invention belongs to the technical field of thermal insulation of transformer substation exterior walls, and in particular relates to a phase-change energy storage concrete wallboard and a preparation method thereof. Background Art

[0002] As the scope of power grid laying expands, more and more substations and other facilities are put into use in various places. In some areas in the north where the temperature difference between summer and winter is large, various problems will be encountered when transmitting electricity in winter. For example, snowstorms and extremely cold weather will significantly affect the normal operation and maintenance of substations, and may also cause related safety accidents. Ensuring that the power system can work normally in winter and minimize losses as much as possible is an urgent problem to be solved. Summary of the invention

[0003] The purpose of the present invention is to provide a phase change energy storage concrete wall panel to solve the problems existing in the above-mentioned prior art. Phase change energy storage building materials are composed of phase change materials and building carrier matrix, and have excellent energy storage and release capabilities; compared with ordinary building insulation materials, they have higher heat capacity and thermal inertia. When the temperature of the microenvironment in which the phase change material is located is lower than the phase change point, the phase change material condenses from liquid to solid, forming heat release; when the temperature of the microenvironment in which the phase change material is located is higher than the phase change point, the phase change material melts from solid to liquid, forming heat absorption. Through this energy storage, the purpose of maintaining room temperature is achieved. The phase change energy storage concrete wall panel provided by this technology can be an energy storage wall panel that can perform phase change cycles in extreme weather to ensure a constant temperature inside the substation.

[0004] One of the technical solutions provided by the present invention:

[0005] A phase-change energy storage concrete wall panel comprises a foam concrete panel with grooves on both sides, phase-change material cement mortar, two corrugated steel panels and two decorative panels, wherein the grooves on both sides of the foam concrete panel are filled with the phase-change material cement mortar, the two corrugated steel panels are respectively fixed on both sides of the foam concrete panel to seal the phase-change material cement mortar, and the two decorative panels are respectively fixed on the two corrugated steel panels.

[0006] The grooves of the foam concrete board in the present invention provide independent storage space, effectively fix the phase change material cement mortar, so that it can complete the phase change cycle more efficiently inside the material, and improve the rate of heat absorption and release. The grooves also prevent the material from leaking out by fixing the phase change material cement mortar in a specific position, thereby ensuring the stability and service life of the overall performance of the wall. In addition, through the design of the grooves, the excessive use of phase change materials is reduced, and only the groove part needs to be filled to achieve the energy storage effect, thereby reducing material costs.

[0007] The corrugated steel plate used in the present invention is a YX15-135-810 steel plate to provide sufficient thermal insulation performance.

[0008] The decorative plate of the present invention adopts a color steel plate to ensure basic strength requirements.

[0009] The preparation method of the phase change material cement mortar comprises the following steps: mixing cement, sand and water, and then adding a gelling phase change material.

[0010] The preparation method of the gelled phase change material comprises: dissolving sodium sulfate decahydrate and calcium chloride dihydrate in water, stirring at low temperature to form a uniform solution, adding poly(acrylamide-co-acrylic acid), continuously stirring until a gelled mixture is formed, and freezing the obtained gelled mixture to obtain the gelled phase change material.

[0011] Sodium sulfate decahydrate is a hydrate salt that can undergo a solid-liquid phase change at around -4°C to release / store heat, and its cost is lower than that of organic materials such as paraffin wax, and its application range is wider. However, sodium sulfate decahydrate is prone to leakage when used in the interlayer of wall panels during the phase change process, and the material itself is unstable and has a short service life. The present invention uses sodium sulfate decahydrate as the main body of the phase change material, and calcium chloride dihydrate is added and mixed to form a eutectic system to enhance the energy storage capacity of the phase change material and increase its service life. The mixed phase change material is then mixed with a poly(acrylamide-co-acrylic acid) organic material with strong adsorption capacity and good water absorption to achieve the purpose of anti-leakage phase change. This composite material also shows good compatibility with cement mortar, and therefore can be used for filling cement mortar in the interlayer of the wall panels in the present invention.

[0012] The present invention uses a new type of sodium sulfate decahydrate-poly(acrylamide-co-acrylic acid) (P(AA-AA)) composite phase change material cement mortar to ensure that the phase change cycle effect can be maintained in a low temperature environment. Even in severe cold weather conditions, the wallboard can still effectively absorb environmental heat sources such as solar radiation and release the stored heat at night, thereby ensuring its normal operation in a low temperature environment.

[0013] The mass ratio of sodium sulfate decahydrate to calcium chloride dihydrate is 7:2; and / or,

[0014] The mass of the poly(acrylamide-co-acrylic acid) is 7% of the sum of the mass of the sodium sulfate decahydrate and the calcium chloride dihydrate.

[0015] The low temperature stirring is stirring at 5°C; and / or

[0016] The freezing temperature is -10°C.

[0017] The mass ratio of cement, sand and water is 1:1:3; and / or

[0018] The mass of the cementitious phase change material is 15% of the total mass of the cement, sand and water.

[0019] The foam concrete board comprises sand and gravel aggregate, water, foaming agent and cement. The foaming agent is an animal protein foaming agent.

[0020] Foamed concrete panels use animal foaming agent protein to make foam and add it to concrete to achieve good thermal insulation, heat exchange and thermal insulation functions.

[0021] The panel body of the present invention is made of foam concrete, which is lighter than traditional prefabricated wall panels, reduces the weight of the building, and is easy to transport and install. The specially proportioned foam concrete improves the compression and bending resistance while ensuring lightness, and can adapt to the needs of different building environments.

[0022] The design of the foam concrete slab uses sand and stone of a certain grade as aggregate, phosphate cement as gelling agent, and the foam is made of animal protein foaming agent. After the foaming agent, dry material and water are mixed and stirred evenly, they are poured into the mold to cast the foam concrete slab with grooves.

[0023] The second technical solution provided by the present invention is:

[0024] A method for preparing the above-mentioned phase change energy storage concrete wall panel comprises mixing the raw materials of the foam concrete panel, using a standard mold with grooves on both sides to pour the mixed raw materials of the foam concrete panel to produce a foam concrete panel with grooves on both sides, pouring phase change material cement mortar into the grooves on both sides of the foam concrete panel, fixing corrugated steel plates on both sides of the foam concrete panel, and then pouring phase change material cement mortar into the remaining gaps, and fixing decorative panels on the corrugated steel plates on both sides after curing to prepare the phase change energy storage concrete wall panel.

[0025] The preparation method provided by the present invention has strong construction convenience. Compared with traditional wall panels, the groove design makes it more convenient to pour the phase change material, without the need for additional filling or packaging processes, further reducing construction costs. The grooved structure improves the thermal energy storage effect of the phase change material, further improves the overall thermal insulation performance of the concrete slab, reduces energy consumption caused by the temperature difference between indoor and outdoor, and improves the energy-saving effect of the building.

[0026] Compared with the prior art, the present invention has the following advantages and technical effects:

[0027] The phase change energy storage method of pouring inorganic phase change mortar into a foam concrete board with grooves is adopted in the present invention to prepare a phase change energy storage concrete wallboard, which has excellent thermal insulation and energy storage performance, can work normally in a low temperature environment, and meets the demand for building energy saving.

[0028] The present invention solves the leakage problem of traditional phase change materials through innovative structural design, significantly improving the building thermal insulation and energy storage performance and construction efficiency. In addition, the phase change energy storage concrete wallboard provided by the present invention has good thermal insulation performance. In practical applications, the thermal insulation capacity can be adjusted by improving the thickness of the wallboard. Good thermal insulation performance can slow down the heat transfer caused by the temperature difference between indoor and outdoor, and is suitable for a variety of climatic conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0030] Figure 1 This is a schematic diagram of the main structure of the phase change energy storage concrete wallboard prepared in Example 1 of the present invention;

[0031] Figure 2 This is a schematic side view of the phase change energy storage concrete wallboard prepared in Example 1 of the present invention;

[0032] Figure 3 This is a schematic diagram of the top view of the phase change energy storage concrete wallboard prepared in Example 1 of the present invention;

[0033] Among them, 1- foam concrete board; 2- corrugated steel plate; 3- groove; 4- phase change material cement mortar. DETAILED DESCRIPTION

[0034] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0035] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0036] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0037] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to the skilled artisan. The present invention description and examples are exemplary only.

[0038] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0039] An embodiment of the present invention provides a method for preparing a phase change energy storage concrete wall panel, which aims to ensure the normal operation of the internal devices of the substation under extreme winter weather conditions through the phase change cycle of phase change materials. In extreme weather conditions, conventional phase change energy storage wall panels lack the corresponding thermal insulation capabilities due to the need to adopt a wrapping solution due to the physical properties of the phase change materials; and the solution of only installing foam concrete with thermal insulation capabilities cannot guarantee the same constant temperature capability as the phase change material sandwich wall panels. The phase change energy storage concrete wall panel provided by the present invention is a concrete panel with grooves for storing phase change materials and performing phase change cycles in the grooves, which can realize the function of using phase change cycles to ensure indoor constant temperature and provide good thermal insulation capabilities.

[0040] The raw materials in the embodiments of the present invention are all purchased from the market, and the animal protein foaming agent is GX-6# foaming agent purchased from Meitujia New Material Technology Co., Ltd. The sand in the embodiments of the present invention is machine-made sand; the cement is magnesium phosphate cement (MPC); the corrugated steel plate used is YX15-135-810 steel plate, and the decorative plate uses color steel plate.

[0041] Example 1

[0042] S1. Preparation of gelled phase change material: Sodium sulfate decahydrate and calcium chloride dihydrate are dissolved in water in a mass ratio of 7:2, stirred at a low temperature of 5°C to form a uniform solution, poly(acrylamide-co-acrylic acid) is added in an amount of 7% of the sum of the mass of sodium sulfate decahydrate and calcium chloride dihydrate, and stirred continuously until a gel-like mixture is formed, the gel-like mixture is poured into a mold and frozen at -10°C for later use;

[0043] S2. Preparation of phase change material cement mortar: Cement, sand and water were mixed in a mass ratio of 1:1:3, and 15% of the sum of the mass of cement, sand and water was added to the gelling phase change material prepared in S1, and mixed evenly to obtain a phase change material cement mortar;

[0044] Example 2

[0045] According to Table 1, weigh sand and gravel aggregate, water, animal protein foaming agent and cement, mix the sand and gravel aggregate and cement, add water and stir evenly, and then add the animal protein foaming agent to prepare foamed concrete.

[0046] Table 1

[0047] Sand and gravel aggregate water Animal protein foaming agent cement 6.45％ 22.58％ 6.45％ 64.52％

[0048] Example 3

[0049] A standard mold with grooves on both sides and a bottom is used to pour the foam concrete prepared in Example 2, and the mold is cured for 7 days at a temperature of 20±3°C and a humidity of more than 80% to produce a foam concrete board 1 with grooves 3 on both sides. The phase change material cement mortar prepared in Example 2 is poured into the grooves 3 on both sides of the foam concrete board. After curing for 28 days at a temperature of 20±1°C and a humidity of 99%, corrugated steel plates 2 are fixed on both sides of the foam concrete board, and then phase change material cement mortar 4 is poured into the remaining gaps. After curing, decorative panels are respectively fixed on the corrugated steel plates on both sides to prepare phase change energy storage concrete wall panels.

[0050] Figure 1 This is a schematic diagram of the main structure of the phase change energy storage concrete wallboard prepared in Example 1 of the present invention;

[0051] Figure 2 This is a schematic side view of the phase change energy storage concrete wallboard prepared in Example 1 of the present invention;

[0052] Figure 3 This is a schematic diagram of the top view of the phase change energy storage concrete wallboard prepared in Example 1 of the present invention;

[0053] Among them, 1- foam concrete board; 2- corrugated steel plate; 3- groove; 4- phase change material cement mortar.

[0054] Comparative Example 1

[0055] Preparation method of ordinary concrete prefabricated wall panels: mix cement, sand and gravel in a mass ratio of 1:2:3, with a water-cement ratio of 0.5. After mixing, pour into the mold, and exhaust and compact through mechanical vibration equipment. After pouring, cure for 7 days in an environment with a temperature of 20±2℃ and a humidity of more than 85% to achieve demolding strength. After demolding, continue to cure in the same environment until 28 days.

[0056] Comparative Example 2

[0057] Preparation method of autoclaved aerated concrete board (AAC board): silica sand, cement, lime and gypsum are mixed in a ratio of 1:0.8:0.2:3, stirred with water to form slurry, then 0.05% aluminum powder is added as a foaming agent, and hydrogen is generated by chemical reaction to expand the slurry to a predetermined volume. After initial setting, the board is cut, and the obtained board is placed in a high-pressure steam curing kettle, autoclaved at 180°C and 1.2MPa for 12 hours, and finally naturally cured until the designed strength is reached to complete the preparation.

[0058] Comparative Example 3

[0059] Preparation method of perlite composite thermal insulation wallboard: the mass ratio of perlite to cement is 1:0.5, the mass ratio of fiber paper to cement is 0.1:0.5, the mass ratio of adhesive to cement is 0.05:0.5, water is added to adjust the consistency of the mixture to be suitable for construction (the water-cement ratio is controlled at 0.460%), and it is naturally dried in an environment. It usually takes 72 hours to reach the demoulding strength, and then it takes 28 days of natural curing to complete the preparation.

[0060] The thermal inertia (I), heat transfer coefficient (U) and heat storage capacity (Q) of the concrete wall panels prepared in Example 3 and Comparative Examples 1-3 were tested. The test results are shown in Table 2. Formula (1) is the calculation formula for thermal inertia, formula (2) is the calculation formula for heat storage, and formula (3) is the calculation formula for heat transfer coefficient.

[0061]

[0062] Where: ρ: material density (kg / m 3 ); c: specific heat capacity (J / (kg·K)); d: wallboard thickness (m);

[0063] λ: Thermal conductivity (W / (m·K))

[0064] Q=m·L (2)

[0065] Where: m: mass of phase change material (kg); L: latent heat of phase change (J / kg)

[0066]

[0067] Where: λ: thermal conductivity (W / (m·K)); d: wallboard thickness (m)

[0068] The lower the U value, the better the heat transfer coefficient.

[0069] Table 2

[0070]

[0071]

[0072] It can be seen from Table 2 that the phase change energy storage concrete wallboard prepared by the present invention has a heat storage capacity of up to 100MJ, which is far more than that of traditional wallboards. It can effectively absorb ambient heat and slowly release it, reduce room temperature fluctuations, and improve the thermal comfort of buildings; it can also reduce the operating time of air conditioning and heating equipment and save energy costs. The thermal inertia of the phase change energy storage concrete wallboard prepared by the present invention is 500,000J·s / (m 2 ·K), which is lower than that of Example 3 and Example 2, but the introduction of phase change materials significantly improves the buffering capacity of ambient temperature fluctuations. Phase change materials effectively stabilize the inner surface temperature of the wall by absorbing and releasing latent heat during temperature changes, making it show unique performance of dynamic thermal regulation in practical applications. Phase ratio 1 (264,000 J·s / (m 2 ·K)), its thermal inertia is improved by nearly 90%, which has significant advantages in buildings requiring thermal stability; the heat transfer coefficient of the phase change energy storage concrete wallboard prepared by the present invention is compared with that of comparative examples 1-3, although the static heat transfer coefficient is 6.0W / (m 2 K), higher than Example 2 (0.65W / (m 2 ·K), but its phase change material can reduce instantaneous heat flux through latent heat effect when the ambient temperature fluctuates. This dynamic thermal performance makes it more valuable in dealing with climate conditions with large temperature differences between day and night. In addition, the groove design not only reduces the weight of the wall panel, but also provides more surface contact with the air, which helps to improve the heat exchange efficiency, thereby optimizing the overall thermal regulation performance.

[0073] The above are only preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A phase change energy storage concrete wallboard, characterized in that: The invention comprises a foam concrete board with grooves on both sides, phase change material cement mortar, two corrugated steel plates and two decorative plates. The grooves on both sides of the foam concrete board are filled with the phase change material cement mortar. The two corrugated steel plates are respectively fixed on both sides of the foam concrete board to seal the phase change material cement mortar. The two decorative plates are respectively fixed on the two corrugated steel plates.

2. The phase change energy storage concrete wallboard according to claim 1 is characterized in that: The preparation method of the phase change material cement mortar comprises the following steps: mixing cement, sand and water, and then adding a gelling phase change material.

3. The phase change energy storage concrete wallboard according to claim 2 is characterized in that: The preparation method of the gelled phase change material comprises: dissolving sodium sulfate decahydrate and calcium chloride dihydrate in water, stirring at low temperature to form a uniform solution, adding poly(acrylamide-co-acrylic acid), continuously stirring until a gelled mixture is formed, and freezing the obtained gelled mixture to obtain the gelled phase change material.

4. The phase change energy storage concrete wallboard according to claim 3 is characterized in that: The mass ratio of sodium sulfate decahydrate to calcium chloride dihydrate is 7:2; and / or, The mass of the poly(acrylamide-co-acrylic acid) is 7% of the sum of the mass of the sodium sulfate decahydrate and the calcium chloride dihydrate.

5. The phase change energy storage concrete wallboard according to claim 3 is characterized in that: The low temperature stirring is stirring at 5°C; and / or The freezing temperature is -10°C.

6. The phase change energy storage concrete wallboard according to claim 2, characterized in that: The mass ratio of cement, sand and water is 1:1:3; and / or The mass of the cementitious phase change material is 15% of the total mass of the cement, sand and water.

7. The phase change energy storage concrete wallboard according to claim 1, characterized in that: The foam concrete board comprises sand and gravel aggregate, water, foaming agent and cement.

8. The phase change energy storage concrete wallboard according to claim 7, characterized in that: The foaming agent is an animal protein foaming agent.

9. A method for preparing the phase change energy storage concrete wallboard according to any one of claims 1 to 8, characterized in that: The raw materials of the foam concrete board are mixed, and the mixed raw materials of the foam concrete board are poured into a standard mold with grooves on both sides to produce a foam concrete board with grooves on both sides. Phase change material cement mortar is poured into the grooves on both sides of the foam concrete board, corrugated steel plates are fixed on both sides of the foam concrete board, and then phase change material cement mortar is poured into the remaining gaps. After curing, decorative panels are respectively fixed on the corrugated steel plates on both sides to prepare phase change energy storage concrete wall panels.

Images