CN104531080B - Metal/organic matter composite medium-low temperature phase change energy storage material and preparation method thereof - Google Patents

Abstract

The present invention discloses a metal/organic composite medium and low temperature phase change energy storage material and a preparation method thereof. The method is to uniformly compound metallic potassium with paraffin wax and metallic sodium with Fischer-Tropsch wax in a glove box in a vacuum inert gas protection atmosphere by a heating ultrasonic stirring method, and then cool and press to form. Metallic potassium and sodium have the characteristics of high thermal conductivity, low melting point, large latent heat and low density. Compounding potassium and sodium with paraffin wax and Fischer-Tropsch wax respectively can not only improve the thermal conductivity of inorganic energy storage materials, but also increase the heat storage capacity of energy storage materials and expand the heat storage density compared with doping with other thermal conductive materials. The prepared metallic potassium/paraffin composite low temperature phase change energy storage material is suitable for thermal energy storage in the low temperature field of 50°C-100°C, and the metallic sodium/Fischer-Tropsch wax composite medium temperature phase change energy storage material is suitable for thermal energy storage in the medium temperature field of 100°C-200°C.

Description

A metal/organic compound medium and low temperature phase change energy storage material and its preparation method

technical field

The invention belongs to the technical field of functional materials, and relates to a composite phase change energy storage material, in particular to a metal/organic compound medium and low temperature phase change energy storage material and a preparation method thereof.

Background technique

During the phase change process of phase change materials, latent heat is released/absorbed, which can be used as thermal energy storage to solve the time and space shortage of energy supply and demand. Compared with sensible heat energy storage, phase change energy storage has high energy density, stable process, and temperature constant characteristics. It has wide application prospects in solar energy utilization, building energy saving, preheating and waste heat recovery, aerospace and special clothing and other fields.

At present, the most widely used organic phase change energy storage materials are paraffin wax and inorganic phase change energy storage materials are molten salts. Paraffin wax is mainly used for low-temperature heat storage at around 50°C-100°C, and molten salt is mainly used for 100°C-400°C Around the medium temperature heat storage. Although phase-change energy storage materials such as paraffin wax and molten salt have the advantages of high heat storage density, strong heat storage capacity, high thermal stability, and low price, the extremely low thermal conductivity of paraffin wax hinders the rate of heat energy storage and release, and has become a popular material. The biggest obstacle to application, the corrosiveness of molten salt under high temperature conditions has become a major problem in the application process.

Scholars at home and abroad are committed to enhancing the thermal conductivity of organic phase change materials. The main methods adopted are:

(1) Add materials with higher thermal conductivity, such as copper powder, aluminum powder, carbon powder and carbon nanotubes, to the phase change material to enhance the heat transfer function. Khan et al. studied the heat transfer characteristics of phase change materials during solidification when aluminum, iron, copper, aluminum-silicon alloys and lead-based composites were added to phase change materials, and pointed out that the movement rate of the solid-liquid interface largely depends on The ratio of the thermal conductivity of the additive to the thermal conductivity of the phase change material after melting [Numerical Heat Transfer, 1994, V25:209-221]. Eman-Bellah et al. studied a solar heat storage system using paraffin as a phase change material, adding aluminum powder to improve the thermal conductivity. The research results show that after adding aluminum powder, the heat storage and heat release time of the system are shortened, and the system performance is improved [Solar Energy, 2007, V81: 839-845];

(2) Composite energy storage materials and pure heat-conducting materials to prepare phase-change materials. The heat-conducting materials in the composite materials only enhance heat transfer and speed up the energy storage/release process. Commonly used heat-conducting materials include porous graphite and metal, expanded graphite, foam metal and other heat-conducting supporting materials. The energy storage material is melt-immersed or vacuum injected into the supporting material to prepare a composite phase-change energy storage material. Xavier et al. used graphite as a support material to adsorb paraffin wax in a graphite matrix with a porous structure to form a graphite matrix/paraffin wax composite phase change material. The thermal conductivity increased from 0.24W/(m K) of pure paraffin wax to 4-70W/ (m·K)[International Journal of Heat and Mass Transfer, 2001, V44:2727-2737]. Sari et al. prepared a paraffin/graphite composite phase change material, and the study showed that the latent heat of the composite phase change material is equivalent to that of pure paraffin [Applied Thermal Engineering. 2007, V27: 1271-1277].

The above two methods can greatly improve the thermal conductivity of energy storage materials, but there are also some shortcomings:

(1) Added or compounded heat-conducting materials only have the function of heat conduction, occupying a certain proportion of energy storage materials reduces the energy storage density, and the energy storage capacity will decrease with the increase in the addition or compounding of heat-conducting materials, resulting in the heat storage capacity and heat conduction of the energy storage coefficient The performance restricts each other and cannot have both;

(2) By adding metal powder or nano thermal conductive materials, the density of energy storage materials and thermal conductive materials is different. During use, a dispersant must be added to fully disperse the thermal conductive materials. However, as the energy storage-energy release process cycles, the function of the dispersant will decrease Gradually fail, resulting in layering of energy storage materials and heat conduction materials due to different densities, and the thermal conductivity gradually weakens. The added dispersant also reduces the energy storage density and phase change latent heat of energy storage materials, which is about 100% less than pure phase change materials. About 10%-30%;

(3) When thermally conductive materials are combined with energy storage materials, the phase change material is usually melted, and then combined with the support material with heat conduction function by immersion or vacuum injection, which is limited by the porosity of the thermally conductive support material and the energy storage material. Kinematic viscosity, the energy storage material cannot achieve 100% injection into the thermal conductivity material, which further reduces the energy storage density, and reduces the phase change latent heat of the energy storage material by about 5%-15% compared with the pure phase change material.

Contents of the invention

In order to overcome the shortcomings of the above-mentioned prior art, the present invention provides a metal/organic composite medium-low temperature phase change energy storage material and its preparation method. The technical problem to be solved is to improve the thermal conductivity of the organic energy storage material and reduce the energy storage capacity of the composite material. The energy capacity is reduced, and the purpose of enhancing the thermal conductivity and heat storage capacity of organic energy storage materials is realized.

In order to solve the above-mentioned technical problem, the technical solution of the present invention is to explore the energy storage-heat conduction working medium pair, so that the thermal conductivity of the energy storage system and the energy storage performance can be perfectly matched, so as to achieve both heat storage capacity and heat conduction performance, and the heat conduction-energy storage work Pairs must have the following characteristics:

1. The thermally conductive material is not only a thermally conductive material during the energy storage process, but also undergoes a phase change to participate in the energy storage process;

2. The heat-conducting material and the energy storage material should have the same phase change temperature, which can realize the synchronization of phase change in the energy storage process and uniform energy storage;

3. The heat-conducting material and the energy storage material must have the same solid-liquid density at the same time, so that any energy storage/energy release solid-liquid transition process materials can be evenly mixed.

After consulting the data, it was found that metal potassium and metal sodium have good thermal conductivity, and have low density and melting point. Potassium metal and paraffin wax have similar solid-liquid density, phase transition temperature and latent heat of phase transition, which are suitable for low-temperature phase change energy storage (50°C-100°C); metallic sodium and Fischer-Tropsch wax also have similar solid-liquid density, phase transition Temperature and latent heat of phase change, suitable for medium temperature phase change energy storage (100°C-200°C).

The phase change energy storage material is a metal/organic composite solid-liquid phase change energy storage material.

The solid-liquid phase change energy storage material is a potassium/paraffin wax composite low temperature phase change energy storage material and a sodium/Fischer-Tropsch wax composite medium temperature phase change energy storage material. The physical parameters of the metal-organic energy storage working fluid pair are shown in the table below.

The preparation of the phase change material:

1. Preparation of potassium/paraffin composite low temperature phase change energy storage materials:

a) Cut 0.05g, 0.1, 0.15, 0.2 and 0.25g metal potassium particles in a vacuum glove box in an inert nitrogen atmosphere, and the numbers are 1-5 respectively;

b) Weigh 4.75g, 4.8g, 4.85g, 4.9g and 4.95g of paraffin in a vacuum glove box with an inert nitrogen atmosphere, put different amounts of paraffin into test tubes numbered 1-5, and place in the glove box Heat the test tube to and maintain at 100°C to ensure that the paraffin in the test tube is completely melted into a liquid state;

c) In the glove box, put the No. 1 potassium metal particles prepared in step a into the No. 5 test tube, put the No. 2 potassium metal particles into the No. 4 test tube, put the No. 3 potassium metal particles into the No. 3 test tube, and put the No. 2 potassium metal particles into the No. 3 test tube. Put No. 2 potassium metal particles into No. 2 test tube, and No. 5 metal potassium particles into No. 1 test tube to ensure that the total mass of metal potassium particles and paraffin in all test tubes is 5g;

d) In the glove box, when the temperature of the ultrasonic instrument is raised and maintained at 100°C, put the test tube into the ultrasonic instrument, set the ultrasonic frequency to 100kHz, put an electric stirrer in the test tube, and use heating, ultrasonic and stirring Disperse metal potassium;

e) In the glove box, pour the homogeneously mixed liquid potassium/paraffin composite material into the mold, cool and press to form.

2. Preparation of sodium/Fischer-Tropsch wax composite medium temperature phase change energy storage material:

a) Cut 0.05g, 0.1, 0.15, 0.2 and 0.25g of metal sodium particles in a vacuum glove box in an inert nitrogen atmosphere, and the numbers are 6-10;

b) Weigh 4.75g, 4.8g, 4.85g, 4.9g and 4.95g of Fischer-Tropsch wax in a vacuum glove box of an inert nitrogen atmosphere, put different amounts of Fischer-Tropsch wax into test tubes numbered 6-10 respectively, Heat and maintain the test tube to 200°C in the glove box to ensure that the Fischer-Tropsch wax in the test tube is completely melted into a liquid state;

c) In the glove box, put the No. 6 metal sodium particles prepared in step a into the No. 10 test tube, the No. 7 metal potassium particles into the No. 9 test tube, and the No. 8 metal sodium particles into the No. 8 test tube. No. 7 metal sodium particles are put into No. 7 test tube, and No. 10 metal sodium particles are put into No. 6 test tube to ensure that the total mass of metal sodium particles and Fischer-Tropsch wax in all test tubes is 5g;

d) In the glove box, when the temperature of the ultrasonic instrument is raised and maintained at 200°C, put the test tube into the ultrasonic instrument, set the ultrasonic frequency to 100kHz, put an electric stirrer in the test tube, and use heating, ultrasonic and stirring methods Dispersed sodium metal;

e) In the glove box, pour the uniformly mixed liquid sodium/Fischer-Tropsch wax composite into the mold, cool and press to form.

The beneficial effect of the present invention is that the potassium/paraffin wax composite material applied to low-temperature energy storage and the sodium/Fischer-Tropsch wax composite material used in medium-temperature energy storage proposed by the present invention not only have high thermal conductivity, but also have relatively large heat storage Density, higher heat storage capacity. The thermal conductivity of the 5%wt potassium/95%wt paraffin composite low-temperature phase change energy storage material measured by the instantaneous method is 6.23W/(m K), which is 21 times that of pure paraffin wax, which is 0.3 W/(m K). , the phase transition temperature of the material measured by differential scanning calorimetry is 60.1°C, and the latent heat of phase transition is 180kJ/kg; the thermal conductivity of 5%wt potassium/95%wt Fischer-Tropsch wax composite medium temperature phase change energy storage material is measured It is 10.58W/(m·K), which is 35 times of the thermal conductivity of pure paraffin wax 0.3 W/(m·K), the phase transition temperature is 98.4°C, and the latent heat of phase transition is 165 kJ/kg.

Description of drawings

Figure 1 is a flow chart for the preparation of potassium/paraffin wax composite low temperature phase change material and sodium/Fischer-Tropsch wax composite medium temperature phase change energy storage material provided by the present invention.

Fig. 2 is a physical photo of the pressed potassium/paraffin wax composite low temperature phase change material and the sodium/Fischer-Tropsch wax composite medium temperature phase change energy storage material provided by the present invention.

detailed description

The following describes the specific implementation of the metal/inorganic compound low-temperature phase-change energy storage material and the preparation method of the present invention, wherein the metal potassium/paraffin wax composite low-temperature phase-change energy storage material and the preparation method are illustrated by Examples 1-5, and the metal sodium The Fischer-Tropsch wax composite medium-temperature phase change material energy storage material and its preparation method are illustrated by Examples 6-10.

Example 1

The potassium/paraffin composite low-temperature phase-change energy storage material and its preparation method include the following steps:

(1) Cut 0.05g metal potassium particles in a vacuum glove box with an inert nitrogen atmosphere;

(2) Weigh 4.95g of paraffin in a vacuum glove box with an inert nitrogen atmosphere, put it into a test tube, heat the test tube to and maintain it at 100°C in the glove box, and ensure that the paraffin in the test tube is completely melted into a liquid state;

(3) In the glove box, put the 0.05g metal potassium particles produced in step (1) into the test tube of 4.95g paraffin wax produced in step (2), to ensure that the total mass of metal potassium particles and paraffin in the test tube is 5g ;

(4) In the glove box, when the temperature of the ultrasonic instrument is raised and maintained at 100°C, put the test tube in step (3) into the ultrasonic instrument, set the ultrasonic frequency to 100kHz, put an electric stirrer in the test tube, and heat , ultrasound and stirring to disperse potassium metal;

(5) In the glove box, the mixed liquid potassium/paraffin composite material prepared in step (4) is poured into a mould, cooled and pressed to shape;

(6) The thermal conductivity of the sample prepared in step (5) was measured by the instantaneous method to be 1.56W/(m K). The phase transition temperature of the material measured by the differential scanning calorimeter was 63.6°C, and the latent heat of phase transition was 205kJ/kg.

Example 2

The potassium/paraffin composite low-temperature phase-change energy storage material and its preparation method include the following steps:

(1) Cut 0.1g metal potassium particles in a vacuum glove box with an inert nitrogen atmosphere;

(2) Weigh 4.9g of paraffin in a vacuum glove box with an inert nitrogen atmosphere, put it into a test tube, heat the test tube to and maintain it at 100°C in the glove box, and ensure that the paraffin in the test tube is completely melted into a liquid state;

(3) In the glove box, put the 0.1g metal potassium particles produced in step (1) into the test tube of 4.9g paraffin wax produced in step (2), ensuring that the total mass of metal potassium particles and paraffin in the test tube is 5g ;

(4) In the glove box, when the temperature of the ultrasonic instrument is raised and maintained at 100°C, put the test tube in step (3) into the ultrasonic instrument, set the ultrasonic frequency to 100kHz, put an electric stirrer in the test tube, and heat , ultrasound and stirring to disperse potassium metal;

(5) In the glove box, the mixed liquid potassium/paraffin composite material prepared in step (4) is poured into a mould, cooled and pressed to shape;

(6) The thermal conductivity of the sample prepared in step (5) was measured by the instantaneous method to be 2.38W/(m K). The phase transition temperature of the material measured by the differential scanning calorimeter was 62.9°C, and the latent heat of phase transition was 194kJ/kg.

Example 3

The potassium/paraffin composite low-temperature phase-change energy storage material and its preparation method include the following steps:

(1) Cut 0.15g metal potassium particles in a vacuum glove box with an inert nitrogen atmosphere;

(2) Weigh 4.85g of paraffin in a vacuum glove box with an inert nitrogen atmosphere, put it into a test tube, heat the test tube to and maintain it at 100°C in the glove box, and ensure that the paraffin in the test tube is completely melted into a liquid state;

(3) In the glove box, put the 0.15g metal potassium particles produced in step (1) into the test tube of 4.85g paraffin wax produced in step (2), to ensure that the total mass of metal potassium particles and paraffin in the test tube is 5g ;

(4) In the glove box, when the temperature of the ultrasonic instrument is raised and maintained at 100°C, put the test tube in step (3) into the ultrasonic instrument, set the ultrasonic frequency to 100kHz, put an electric stirrer in the test tube, and heat , ultrasound and stirring to disperse potassium metal;

(5) In the glove box, the mixed liquid potassium/paraffin composite material prepared in step (4) is poured into a mould, cooled and pressed to shape;

(6) The thermal conductivity of the sample prepared in step (5) was measured by the instantaneous method to be 3.72W/(m K). The phase transition temperature of the material measured by the differential scanning calorimeter was 62.1°C, and the latent heat of phase transition was 189kJ/kg.

Example 4

The potassium/paraffin composite low-temperature phase-change energy storage material and its preparation method include the following steps:

(1) Cut 0.2g metal potassium particles in a vacuum glove box with an inert nitrogen atmosphere;

(2) Weigh 4.8g of paraffin in a vacuum glove box in an inert nitrogen atmosphere, put it into a test tube, heat the test tube to and maintain it at 100°C in the glove box, and ensure that the paraffin in the test tube is completely melted into a liquid state;

(3) In the glove box, put the 0.2g metal potassium particles produced in step (1) into the test tube of 4.8g paraffin wax produced in step (2), ensuring that the total mass of metal potassium particles and paraffin in the test tube is 5g ;

(4) In the glove box, when the temperature of the ultrasonic instrument is raised and maintained at 100°C, put the test tube in step (3) into the ultrasonic instrument, set the ultrasonic frequency to 100kHz, put an electric stirrer in the test tube, and heat , ultrasound and stirring to disperse potassium metal;

(5) In the glove box, the mixed liquid potassium/paraffin composite material prepared in step (4) is poured into a mould, cooled and pressed to shape;

(6) The thermal conductivity of the sample prepared in step (5) was measured by the instantaneous method to be 5.04W/(m K). The phase transition temperature of the material measured by the differential scanning calorimeter was 61.3°C, and the latent heat of phase transition was 185kJ/kg.

Example 5

The potassium/paraffin composite low-temperature phase-change energy storage material and its preparation method include the following steps:

(1) Cut 0.25g metal potassium particles in a vacuum glove box in an inert nitrogen atmosphere;

(2) Weigh 4.75g of paraffin in a vacuum glove box with an inert nitrogen atmosphere, put it into a test tube, heat the test tube to and maintain it at 100°C in the glove box, and ensure that the paraffin in the test tube is completely melted into a liquid state;

(3) In the glove box, put the 0.25g potassium metal particles produced in step (1) into the test tube of 4.75g paraffin wax produced in step (2), ensuring that the total mass of potassium metal particles and paraffin in the test tube is 5g ;

(4) In the glove box, when the temperature of the ultrasonic instrument is raised and maintained at 100°C, put the test tube in step (3) into the ultrasonic instrument, set the ultrasonic frequency to 100kHz, put an electric stirrer in the test tube, and heat , ultrasound and stirring to disperse potassium metal;

(5) In the glove box, the mixed liquid potassium/paraffin composite material prepared in step (4) is poured into a mould, cooled and pressed to shape;

(6) The thermal conductivity of the sample prepared in step (5) was measured by the instantaneous method to be 6.23W/(m K). The phase transition temperature of the material measured by the differential scanning calorimeter was 60.1°C, and the latent heat of phase transition was 180kJ/kg.

Example 6

The sodium/Fischer-Tropsch wax composite medium-temperature phase-change energy storage material and its preparation method include the following steps:

(1) Cut 0.05g metal sodium particles in a vacuum glove box with an inert nitrogen atmosphere;

(2) Weigh 4.95g of Fischer-Tropsch wax in a vacuum glove box with an inert nitrogen atmosphere, put it into a test tube, heat the test tube to and maintain it at 200°C in the glove box, and ensure that the Fischer-Tropsch wax in the test tube is completely melted into a liquid state ;

(3) In the glove box, the 0.05g sodium metal particles produced by step (1) are put into the test tube of the 4.95g Fischer-Tropsch wax produced by step (2), to ensure the separation between the sodium metal particles and the Fischer-Tropsch wax in the test tube The total mass is 5g;

(4) In the glove box, when the temperature of the ultrasonic instrument is raised and maintained at 200°C, put the test tube in step (3) into the ultrasonic instrument, set the ultrasonic frequency to 100kHz, put an electric stirrer in the test tube, and heat , ultrasound and stirring to disperse sodium metal;

(5) In the glove box, the uniformly mixed liquid sodium/Fischer-Tropsch wax composite material prepared in step (4) is poured into a mould, cooled and pressed into shape;

(6) The thermal conductivity of the sample prepared in step (5) was measured by the instantaneous method to be 2.35W/(m K). The phase transition temperature of the material measured by the differential scanning calorimeter was 103.8°C, and the latent heat of phase transition was 178kJ/kg.

Example 7

The sodium/Fischer-Tropsch wax composite medium-temperature phase-change energy storage material and its preparation method include the following steps:

(1) Cut 0.1g metal sodium particles in a vacuum glove box with an inert nitrogen atmosphere;

(2) Weigh 4.9g of Fischer-Tropsch wax in a vacuum glove box with an inert nitrogen atmosphere, put it into a test tube, heat and maintain the test tube at 200°C in the glove box, and ensure that the Fischer-Tropsch wax in the test tube is completely melted into a liquid state ;

(3) In the glove box, the 0.1g sodium metal particles produced by step (1) are put into the test tube of the 4.9g Fischer-Tropsch wax produced by step (2), to ensure the separation between the sodium metal particles and the Fischer-Tropsch wax in the test tube The total mass is 5g;

(4) In the glove box, when the temperature of the ultrasonic instrument is raised and maintained at 200°C, put the test tube in step (3) into the ultrasonic instrument, set the ultrasonic frequency to 100kHz, put an electric stirrer in the test tube, and heat , ultrasound and stirring to disperse sodium metal;

(5) In the glove box, the uniformly mixed liquid sodium/Fischer-Tropsch wax composite material prepared in step (4) is poured into a mould, cooled and pressed into shape;

(6) The thermal conductivity of the sample prepared in step (5) was measured by the instantaneous method to be 4.52W/(m K). The phase transition temperature of the material measured by the differential scanning calorimeter was 101.9°C, and the latent heat of phase transition was 175kJ/kg.

Example 8

The sodium/Fischer-Tropsch wax composite medium-temperature phase-change energy storage material and its preparation method include the following steps:

(1) Cut 0.15g metal sodium particles in a vacuum glove box with an inert nitrogen atmosphere;

(2) Weigh 4.85g of Fischer-Tropsch wax in a vacuum glove box with an inert nitrogen atmosphere, put it into a test tube, heat and maintain the test tube at 200°C in the glove box, and ensure that the Fischer-Tropsch wax in the test tube is completely melted into a liquid state ;

(3) In the glove box, put the 0.15g sodium metal particles produced by step (1) into the test tube of 4.85g Fischer-Tropsch wax produced by step (2), to ensure the separation of sodium metal particles and Fischer-Tropsch wax in the test tube The total mass is 5g;

(4) In the glove box, when the temperature of the ultrasonic instrument is raised and maintained at 200°C, put the test tube in step (3) into the ultrasonic instrument, set the ultrasonic frequency to 100kHz, put an electric stirrer in the test tube, and heat , ultrasound and stirring to disperse sodium metal;

(5) In the glove box, the uniformly mixed liquid sodium/Fischer-Tropsch wax composite material prepared in step (4) is poured into a mould, cooled and pressed into shape;

(6) The thermal conductivity of the sample prepared in step (5) was measured by the instantaneous method to be 6.46W/(m K). The phase transition temperature of the material measured by the differential scanning calorimeter was 100.6°C, and the latent heat of phase transition was 171kJ/kg.

Example 9

The sodium/Fischer-Tropsch wax composite medium-temperature phase-change energy storage material and its preparation method include the following steps:

(1) Cut 0.2g metal sodium particles in a vacuum glove box with an inert nitrogen atmosphere;

(2) Weigh 4.8g of Fischer-Tropsch wax in a vacuum glove box with an inert nitrogen atmosphere, put it into a test tube, heat and maintain the test tube at 200°C in the glove box, and ensure that the Fischer-Tropsch wax in the test tube is completely melted into a liquid state ;

(3) In the glove box, put the 0.2g sodium metal particles produced by step (1) into the test tube of 4.8g Fischer-Tropsch wax produced by step (2), to ensure the separation of sodium metal particles and Fischer-Tropsch wax in the test tube The total mass is 5g;

(4) In the glove box, when the temperature of the ultrasonic instrument is raised and maintained at 200°C, put the test tube in step (3) into the ultrasonic instrument, set the ultrasonic frequency to 100kHz, put an electric stirrer in the test tube, and heat , ultrasound and stirring to disperse sodium metal;

(5) In the glove box, the uniformly mixed liquid sodium/Fischer-Tropsch wax composite material prepared in step (4) is poured into a mould, cooled and pressed into shape;

(6) The thermal conductivity of the sample prepared in step (5) was measured by the instantaneous method to be 8.26W/(m K). The phase transition temperature of the material measured by the differential scanning calorimeter was 99.5°C, and the latent heat of phase transition was 168kJ/kg.

Example 10

The sodium/Fischer-Tropsch wax composite medium-temperature phase-change energy storage material and its preparation method include the following steps:

(1) Cut 0.25g metal sodium particles in a vacuum glove box with an inert nitrogen atmosphere;

(2) Weigh 4.75g of Fischer-Tropsch wax in a vacuum glove box with an inert nitrogen atmosphere, put it into a test tube, heat and maintain the test tube at 200°C in the glove box, and ensure that the Fischer-Tropsch wax in the test tube is completely melted into a liquid state ;

(3) In the glove box, put the 0.25g sodium metal particles produced by step (1) into the test tube of 4.75g Fischer-Tropsch wax produced by step (2), to ensure the separation of sodium metal particles and Fischer-Tropsch wax in the test tube The total mass is 5g;

(4) In the glove box, when the temperature of the ultrasonic instrument is raised and maintained at 200°C, put the test tube in step (3) into the ultrasonic instrument, set the ultrasonic frequency to 100kHz, put an electric stirrer in the test tube, and heat , ultrasound and stirring to disperse sodium metal;

(5) In the glove box, the uniformly mixed liquid sodium/Fischer-Tropsch wax composite material prepared in step (4) is poured into a mould, cooled and pressed into shape;

(6) The thermal conductivity of the sample prepared in step (5) was measured by the instantaneous method to be 10.58W/(m K). The phase transition temperature of the material measured by the differential scanning calorimeter was 98.4°C, and the latent heat of phase transition was 165kJ/kg.

Claims (4)

1. A kind of 1. metallic potassium/paraffin compound cryosar phase-changing energy storage material preparation method, it is characterised in that following steps：

   (1) 0.05g, 0.1g, 0.15g, 0.2g and 0.25g metallic potassium are respectively cut in the vacuum glove box of inert nitrogen atmosphere Grain, numbering are respectively 1-5；

   (2) 4.75g, 4.8g, 4.85g, 4.9g and 4.95g paraffin are weighed in the vacuum glove box of inert nitrogen atmosphere, will not Paraffin with deal is put into the test tube that numbering is respectively 1-5, and test tube is heated in glove box and maintains 100 DEG C, really Protect invisible spectro paraffin and be melted into liquid completely；

   (3) in glove box, No. 1 metallic potassium grain that step (1) is produced is put into No. 5 test tubes, and No. 2 metallic potassium grains are put into No. 4 In test tube, No. 3 metallic potassium grains are put into No. 3 test tubes, and No. 4 metallic potassium grains are put into No. 2 test tubes, and No. 5 metallic potassium grains are put into No. 1 examination In pipe, it is ensured that the gross mass of metallic potassium grain and paraffin is 5g in all test tubes, and metallic potassium is 1 with Quality of Paraffin Waxes ratio:99、2: 98、3:97、4:96 and 5:95；

   (4) in glove box, when ultrasonic instrument temperature raises and is maintained at 100 DEG C, test tube is put into ultrasonic instrument, set super Acoustic frequency is 100kHz, is in vitro put into electric mixer, the dispersed metal potassium by the way of heating, ultrasound and stirring；

   (5) in glove box, well mixed liquid potassium/paraffin composite is poured into mould, cooling is compressing.
2. A kind of 2. metallic sodium/Fischer-Tropsch wax composite medium-temperature phase-changing energy storage material preparation method, it is characterised in that following steps：

   (1) 0.05g, 0.1g, 0.15g, 0.2g and 0.25g metallic sodium are respectively cut in the vacuum glove box of inert nitrogen atmosphere Grain, numbering are respectively 6-10；

   (2) 4.75g, 4.8g, 4.85g, 4.9g and 4.95g Fischer-Tropsch wax are weighed in the vacuum glove box of inert nitrogen atmosphere, will The Fischer-Tropsch wax of different deals is put into the test tube that numbering is respectively 6-10, test tube will be heated to and be maintained in glove box 200 DEG C, it is ensured that invisible spectro Fischer-Tropsch wax is melted into liquid completely；

   (3) in glove box, No. 6 metallic sodium grains that step (1) is produced are put into No. 10 test tubes, and No. 7 metallic potassium grains are put into No. 9 In test tube, No. 8 metallic sodium grains are put into No. 8 test tubes, and No. 9 metallic sodium grains are put into No. 7 test tubes, and No. 10 metallic sodium grains are put into No. 6 In test tube, it is ensured that the gross mass of metallic sodium grain and Fischer-Tropsch wax is 5g in all test tubes, and metallic sodium is 1 with Fischer-Tropsch wax mass ratio: 99、2:98、3:97、4:96 and 5:95；

   (4) in glove box, when ultrasonic instrument temperature raises and is maintained at 200 DEG C, test tube is put into ultrasonic instrument, set super Acoustic frequency is 100kHz, is in vitro put into electric mixer, the dispersed metal sodium by the way of heating, ultrasound and stirring；

   (5) in glove box, well mixed Liquid Sodium/Fischer-Tropsch wax composite is poured into mould, cooling is compressing.
3. 3. a kind of application of metallic potassium according to claim 1/paraffin compound cryosar phase-changing energy storage material preparation method, its It is characterised by, metallic potassium/paraffin compound cryosar phase-changing energy storage material prepared by this method is led suitable for 50 DEG C -100 DEG C of low temperature The thermal energy storage in domain.
4. 4. a kind of application of metallic sodium according to claim 2/Fischer-Tropsch wax composite medium-temperature phase-changing energy storage material preparation method, Characterized in that, metallic sodium/Fischer-Tropsch wax composite medium-temperature phase-changing energy storage material prepared by this method is suitable for 100 DEG C -200 DEG C The thermal energy storage in warm field.