Medium-high temperature composite structural heat storage material, preparation method and application thereof

Abstract

The invention relates to a medium-high temperature (120-1000 DEG C or higher) composite structural heat storage material. The medium-high temperature composite structural heat storage material comprises an inorganic salt phase change latent heat material, a sensitive heat storage material and a heat conduction reinforcing material, wherein the mass ratio of the inorganic salt phase change latent heat material to the sensitive heat storage material is of 1: (0.1-10); and the heat conduction reinforcing material is of 0.0001-1kg / (kg heat storage material) based on mass ratio. The preparation method comprises steps as follows: uniformly mixing the inorganic salt phase change latent heat material with the sensitive heat storage material and the heat conduction reinforcing material; pressurizing to form green blank; and then heating and sintering, so as to obtain the medium-high temperature composite structural heat storage material. The medium-high temperature composite structural heat storage material provided by the invention is capable of obviously reducing the corrosion resistance of the sensitive heat storage material; meanwhile, the thermal conductivity of the composite heat storage material is markedly improved by virtue of the micro-nano doping of the heat conduction reinforcing material; and moreover, high heat storage density is achieved, and wide application prospect is provided.

Description

technical field

[0001] The present invention relates to the technical field of producing heat storage materials by chemical and chemical methods and the field of energy material science and technology. Specifically, the present invention relates to a composite of inorganic salt phase change latent heat storage materials, sensible heat storage materials, and heat conduction enhancement materials. Structural heat storage materials and preparation methods and application fields of composite structural heat storage materials. Background technique

[0002] The dispersion and large energy level span of industrial waste heat, as well as the intermittent nature of renewable energy, require heat storage technology. Medium-high temperature heat storage technology refers to the use of heat storage materials to store medium-high temperature waste heat or low-grade heat in the temperature range of 120-1000°C or higher, and release it when needed, trying to solve the problem of heat energ...

Examples

Embodiment 1

[0053] Take the mass ratio Na 2 CO 3 : Li 2 CO 3 5 kg of molten salt system of 1:0.75, ground to 120 mesh, added 5 kg of magnesia, 0.05 kg of carbon nanotubes mixed and ground thoroughly, prepared briquettes with a steel abrasive tool with a diameter of Φ15 mm under a constant pressure of 5 MPa for 5 minutes, and removed Take out the pressed sample and put it into the crucible, the temperature rise rate is 5°C / min from room temperature to 400°C, 1°C / min from 400°C to 550°C, keep at 550°C for 90min, and cool at the same rate at the same stage. The thermal analysis curve of the obtained material is as follows figure 1 As shown, it can be seen that the thermophysical properties of the composite system are good, and the heat storage density is above 525kJ / kg in the temperature range of 300-600°C. The XRD pattern of the composite heat storage material is as follows: figure 2As shown, the results show that when magnesium oxide is used as a sensible heat storage material and a ...

Embodiment 2

[0055] Take 5kg of molten salt system with a mass ratio of NaCl:KCl of 1:1.3, grind it through 120 mesh, add 5kg of silicon oxide, mix and grind fully, add 0.05kg of graphite powder, mix well, take an appropriate amount of mixed powder with a length and width of 50×20mm The briquette was prepared under a constant pressure of 5 MPa on a steel abrasive tool, and the pressure holding time was 5 minutes. The pressed sample was removed from the mold and placed in a crucible. The heating rate was 5°C / min from room temperature to 550°C, and 1°C / min from Rise from 550°C to 700°C, hold at 700°C for 90 minutes, and cool at the same rate at the same stage. The thermal analysis results of the obtained material are as follows Figure 4 As shown, the composite heat storage material of chloride and silicon oxide has high heat storage density and good chemical compatibility ( Figure 5 ), the thermal conductivity of the composite material is significantly improved.

Embodiment 3

[0057] Take 5kg of molten salt system with a mass ratio of KCl:LiCl of 1:0.85, grind to 120 mesh, add 5kg of silicon carbide, mix and grind fully, add 0.2kg of stainless steel wire, mix well, take an appropriate amount of mixed powder with a length and width of 50×20mm The briquette was prepared under a constant pressure of 5 MPa on a steel abrasive tool, and the pressure holding time was 5 minutes. The pressed sample was removed from the mold and placed in a crucible. The heating rate was 5°C / min from room temperature to 250°C, and 1°C / min from Rise from 250°C to 400°C, hold at 400°C for 90 minutes, and cool at the same rate at the same stage. The total heat storage density of KCl+LiCl molten salt is higher ( Figure 6 ), better chemical compatibility with silicon carbide composites ( Figure 7 ), the silicon carbide composite chloride heat storage material has better thermal conductivity.

technical field

[0001] The present invention relates to the technical field of producing heat storage materials by chemical and chemical methods and the field of energy material science and technology. Specifically, the present invention relates to a composite of inorganic salt phase change latent heat storage materials, sensible heat storage materials, and heat conduction enhancement materials. Structural heat storage materials and preparation methods and application fields of composite structural heat storage materials. Background technique

[0002] The dispersion and large energy level span of industrial waste heat, as well as the intermittent nature of renewable energy, require heat storage technology. Medium-high temperature heat storage technology refers to the use of heat storage materials to store medium-high temperature waste heat or low-grade heat in the temperature range of 120-1000°C or higher, and release it when needed, trying to solve the problem of heat energ...

Examples

Embodiment 1

[0053] Take the mass ratio Na 2 CO 3 : Li 2 CO 3 5 kg of molten salt system of 1:0.75, ground to 120 mesh, added 5 kg of magnesia, 0.05 kg of carbon nanotubes mixed and ground thoroughly, prepared briquettes with a steel abrasive tool with a diameter of Φ15 mm under a constant pressure of 5 MPa for 5 minutes, and removed Take out the pressed sample and put it into the crucible, the temperature rise rate is 5°C / min from room temperature to 400°C, 1°C / min from 400°C to 550°C, keep at 550°C for 90min, and cool at the same rate at the same stage. The thermal analysis curve of the obtained material is as follows figure 1 As shown, it can be seen that the thermophysical properties of the composite system are good, and the heat storage density is above 525kJ / kg in the temperature range of 300-600°C. The XRD pattern of the composite heat storage material is as follows: figure 2As shown, the results show that when magnesium oxide is used as a sensible heat storage material and a ...

Embodiment 2

[0055] Take 5kg of molten salt system with a mass ratio of NaCl:KCl of 1:1.3, grind it through 120 mesh, add 5kg of silicon oxide, mix and grind fully, add 0.05kg of graphite powder, mix well, take an appropriate amount of mixed powder with a length and width of 50×20mm The briquette was prepared under a constant pressure of 5 MPa on a steel abrasive tool, and the pressure holding time was 5 minutes. The pressed sample was removed from the mold and placed in a crucible. The heating rate was 5°C / min from room temperature to 550°C, and 1°C / min from Rise from 550°C to 700°C, hold at 700°C for 90 minutes, and cool at the same rate at the same stage. The thermal analysis results of the obtained material are as follows Figure 4 As shown, the composite heat storage material of chloride and silicon oxide has high heat storage density and good chemical compatibility ( Figure 5 ), the thermal conductivity of the composite material is significantly improved.

Embodiment 3

[0057] Take 5kg of molten salt system with a mass ratio of KCl:LiCl of 1:0.85, grind to 120 mesh, add 5kg of silicon carbide, mix and grind fully, add 0.2kg of stainless steel wire, mix well, take an appropriate amount of mixed powder with a length and width of 50×20mm The briquette was prepared under a constant pressure of 5 MPa on a steel abrasive tool, and the pressure holding time was 5 minutes. The pressed sample was removed from the mold and placed in a crucible. The heating rate was 5°C / min from room temperature to 250°C, and 1°C / min from Rise from 250°C to 400°C, hold at 400°C for 90 minutes, and cool at the same rate at the same stage. The total heat storage density of KCl+LiCl molten salt is higher ( Figure 6 ), better chemical compatibility with silicon carbide composites ( Figure 7 ), the silicon carbide composite chloride heat storage material has better thermal conductivity.

Images