Method for preparing sodium chloride powder as PCM high-temperature heat storage material

Abstract

The invention discloses a preparation method of a PCM (phase change material) with sodium chloride powder as a PCM high-temperature heat storage material, belongs to the field of high-temperature heat storage materials, and discloses a novel NaCl / Al2O3 powder composite structure PCM and a preparation method thereof. The preparation method of the novel NaCl / Al2O3 powder composite structure PCM high-temperature heat storage material is simple and low in cost, the prepared PCM material has high shape retention performance and can be effectively applied to the field of high-temperature heat storage, and a new solution is provided for development of a high-temperature heat storage technology.

Description

Technical Field

[0001] The invention relates to the field of high-temperature heat storage materials, and in particular to a method for preparing sodium chloride powder as PCM high-temperature heat storage material. Background Art

[0002] Phase change materials (PCMs) are a type of material that can absorb or release a large amount of heat when the temperature changes. They have the characteristics of absorbing heat when storing heat at low temperatures and releasing heat when storing heat at high temperatures. Therefore, they have broad application prospects in the field of energy storage. Inorganic salt phase change materials such as sodium chloride (NaCl) are widely used in high-temperature heat storage systems due to their high melting point (801°C) and high latent heat storage density (482kJ / kg). However, since NaCl is easy to leak and corrosive when in liquid state, and its melting point is high, conventional metals are difficult to use for packaging. Therefore, how to effectively encapsulate NaCl has become a key issue restricting its application. Traditional methods usually use sintered ceramic shells for packaging, but because sintered ceramic shells have good wettability to ceramics and large volume expansion when melted, there are certain difficulties and technical challenges in the packaging process. Summary of the invention

[0003] The present invention is intended to provide a method for preparing sodium chloride powder as a PCM high-temperature heat storage material to solve the problems raised in the above background technology.

[0004] In order to achieve the above object, the present invention provides the following technical solutions:

[0005] A method for preparing sodium chloride powder as PCM high temperature heat storage material, characterized in that it comprises the following steps:

[0006] S1: Preparation of NaCl / Al2O3 powder composites

[0007] Al2O3 powder and NaCl powder are mixed at a predetermined volume concentration, and the mixed volume concentration can be selected as 60, 70, 80 and 90 vol% NaCl, and then a granulation binder 1wt% CMC aqueous solution is added to a resin mold with a diameter of 20, 30, 40, and 50 mm to prepare NaCl / Al2O3 powder composite material balls. After drying at room temperature and 90°C for 1 hour, the mold is demolded to obtain NaCl / Al2O3 powder composite material balls;

[0008] S2: Preparation of phase change capsules

[0009] A 100:1 ratio of Al2O3 is added to SiC powder to prepare a mixed powder, water and a binder are added to prepare a cement slurry, the NaCl / Al2O3 powder composite material ball obtained by demolding in S1 is placed in a shell-making mold, SiC cement slurry is poured into the mold to wrap the small ball, and the shells of 20mm, 30mm, 40mm and 50mm small balls are 2mm, 3mm, 4mm and 5mm respectively, and then dried and shaped;

[0010] S3: Heating shape retention performance test

[0011] Step S2: The obtained 80 vol% NaCl / 20 vol% Al2O3 powder composite material balls are heated to 850°C for 10 minutes on a SiC castable matrix to obtain shaped NaCl capsules as high-temperature heat storage phase change material.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] The novel NaCl / Al2O3 powder composite structure PCM high-temperature heat storage material of the present invention has a simple preparation method and low cost, and the prepared PCM material has high shape retention performance and can be effectively applied to the field of high-temperature heat storage, providing a new solution for the development of high-temperature heat storage technology, which can significantly improve the stability of phase change capsules and reduce the probability of leakage at high temperatures. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The present invention is a flow chart of a method for preparing sodium chloride powder as PCM high-temperature heat storage material. DETAILED DESCRIPTION

[0015] The present invention is further described in detail below in conjunction with the embodiments:

[0016] like Figure 1 As shown, a method for preparing sodium chloride powder as PCM high temperature heat storage material is characterized by comprising the following steps:

[0017] S1: Preparation of NaCl / Al2O3 powder composites

[0018] Al2O3 powder and NaCl powder are mixed at a predetermined volume concentration, and the mixed volume concentration can be selected as 60, 70, 80 and 90 vol% NaCl, and then a granulation binder 1wt% CMC aqueous solution is added to a resin mold with a diameter of 20, 30, 40, and 50 mm to prepare NaCl / Al2O3 powder composite material balls. After drying at room temperature and 90°C for 1 hour, the mold is demolded to obtain NaCl / Al2O3 powder composite material balls;

[0019] S2: Preparation of phase change capsules

[0020] A 100:1 ratio of Al2O3 is added to SiC powder to prepare a mixed powder, water and a binder are added to prepare a cement slurry, the NaCl / Al2O3 powder composite material ball obtained by demolding in S1 is placed in a shell-making mold, SiC cement slurry is poured into the mold to wrap the small ball, and the shells of 20mm, 30mm, 40mm and 50mm small balls are 2mm, 3mm, 4mm and 5mm respectively, and then dried and shaped;

[0021] S3: Heating shape retention performance test

[0022] Step S2: The obtained 80 vol% NaCl / 20 vol% Al2O3 powder composite material balls are heated to 850°C for 10 minutes on a SiC castable matrix to obtain shaped NaCl capsules as high-temperature heat storage phase change material.

[0023] The specific implementation process is as follows:

[0024] 60g of Al2O3 powder and 40g of NaCl powder were mixed to form a mixture of 60vol% NaCl. 0.6g of CMC aqueous solution was added to a resin mold with a diameter of 12mm to prepare NaCl / Al2O3 powder composite material balls. After drying at 90℃ for 1 hour, the balls were demoulded to obtain NaCl / Al2O3 powder composite material balls. Then, the balls were encapsulated into ceramic shells using a ceramic molding process.

[0025] The above is only an embodiment of the present invention, and the common knowledge such as the known specific technical solutions and / or characteristics in the solution is not described in detail here. It should be pointed out that for those skilled in the art, without departing from the technical solution of the present invention, several modifications and improvements can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A method for preparing sodium chloride powder as PCM high temperature heat storage material, characterized in that: The steps include: S1: Preparation of NaCl / Al2O3 powder composites Al2O3 powder and NaCl powder are mixed at a predetermined volume concentration, and the mixed volume concentration can be selected as 60, 70, 80 and 90 vol% NaCl, and then a granulation binder 1wt% CMC aqueous solution is added to a resin mold with a diameter of 20, 30, 40, and 50 mm to prepare NaCl / Al2O3 powder composite material balls. After drying at room temperature and 90°C for 1 hour, the mold is demolded to obtain NaCl / Al2O3 powder composite material balls; S2: Preparation of phase change capsules A 100:1 ratio of Al2O3 is added to SiC powder to prepare a mixed powder, water and a binder are added to prepare a cement slurry, the NaCl / Al2O3 powder composite material ball obtained by demolding in S1 is placed in a shell-making mold, SiC cement slurry is poured into the mold to wrap the small ball, and the shells of 20mm, 30mm, 40mm and 50mm small balls are 2mm, 3mm, 4mm and 5mm respectively, and then dried and shaped; S3: Heating shape retention performance test Step S2: The obtained 80 vol% NaCl / 20 vol% Al2O3 powder composite material balls are heated to 850°C for 10 minutes on a SiC castable matrix to obtain shaped NaCl capsules as high-temperature heat storage phase change material.

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