High-temperature solid heat storage material based on industrial solid waste, and preparation method and heat storage pile thereof

Abstract

The application provides a high-temperature solid heat storage material based on industrial solid waste and a preparation method and a heat storage pile thereof, and belongs to the technical field of new energy and energy storage and energy saving materials. The application prepares a high-temperature solid heat storage material by introducing three functional additives in cooperation: a composite alkali-boron activator is used to bond and form the solid waste raw materials into a shape through a geological polymerization reaction at a low temperature, and is converted into a fluxing agent at a high temperature to promote the low-temperature densification of the material; a core-shell structure heat conduction enhancer with an antioxidant glass shell layer constructs an efficient three-dimensional heat conduction network in the material, and improves the heat conduction rate; meanwhile, Li-Al-Si glass phase precursor powder induces the precipitation of low-thermal-expansion microcrystals at a third temperature stage, and gives the material thermal shock stability through a micro stress compensation mechanism; the three additives cooperate to improve the heat storage performance and mechanical stability of the material.

Description

Technical Field

[0001] This invention belongs to the field of new energy and energy storage materials technology, and relates to a high-temperature solid thermal storage material based on industrial solid waste, its preparation method and thermal storage stack. Background Technology

[0002] With the rapid development of renewable energy, its intermittency and instability pose significant challenges to the stable operation of the power grid. Large-scale energy storage technology is key to solving this problem. Among various energy storage technologies, sensible thermal energy storage has broad application prospects in large-scale energy storage due to its mature technology, low cost, and long lifespan. Solid thermal storage media are the core of sensible thermal energy storage technology, and their performance directly determines the efficiency and cost of the thermal storage system. Currently, commonly used solid thermal storage materials include refractory bricks, ceramics, natural rocks (such as basalt), and concrete. However, these materials are either expensive (such as specialized ceramics), have limited thermal density (such as ordinary rocks), or are prone to pulverization and cracking at high temperatures (such as ordinary concrete), which limits their large-scale commercial application.

[0003] On the other hand, my country generates billions of tons of industrial solid waste annually, such as coal gangue, fly ash, blast furnace slag, and steel slag. The large-scale stockpiling of these solid wastes not only occupies land but also causes serious environmental pollution and ecological damage. How to achieve high-value-added resource utilization of bulk industrial solid waste is a major social and environmental problem that urgently needs to be solved. Meanwhile, some industrial solid wastes (such as fly ash and certain metallurgical slags) contain high levels of SiO2 and Fe2O3, possessing good refractory properties and certain mechanical strength. With appropriate formulation and processing, they hold promise for development into high-performance, low-cost heat storage media. Summary of the Invention

[0004] To address the aforementioned problems, the present invention aims to provide a high-temperature solid thermal storage material based on industrial solid waste, its preparation method, and a thermal storage reactor. This application introduces three synergistic functional additives to prepare a high-temperature solid thermal storage material: a composite alkali-boron activator binds the solid waste raw materials into shape through a geological polymerization reaction at low temperatures, and transforms it into a flux at high temperatures to promote low-temperature densification of the material; a core-shell structure thermal conductivity enhancer with an antioxidant glass shell constructs a highly efficient three-dimensional thermal conductivity network within the material, improving the thermal conductivity rate; simultaneously, Li-Al-Si vitrification precursor powder induces the precipitation of low-thermal-expansion microcrystals in the third temperature stage, endowing the material with thermal shock resistance through a micro-stress compensation mechanism; the synergistic effect of the three additives enhances the material's thermal storage performance and mechanical stability.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] In a first aspect, the present invention provides a method for preparing a high-temperature solid thermal storage material based on industrial solid waste, the method comprising:

[0007] S1: Dispersion A is obtained by mixing sodium hydroxide with deionized water, and dispersion B is obtained by adding sodium metaborate; silicon source is obtained by mixing water glass with silica sol, and silicon source is added to dispersion B. After stirring evenly, a composite alkali-boron activator solution is obtained.

[0008] S2: Tetraethyl orthosilicate and phosphoric acid are dispersed in a mixed solvent to obtain a preliminary phosphorus-silicate precursor sol. The mixed solvent is a mixture of anhydrous ethanol and deionized water. Polyvinylpyrrolidone is added to obtain the phosphorus-silicate precursor sol. Metallurgical coke powder is dispersed in the phosphorus-silicate precursor sol, stirred, dried, and ground to obtain a core-shell structure thermal conductivity enhancer.

[0009] S3: Lithium carbonate, kaolin and quartz powder are uniformly mixed to obtain a mixed powder, which is then calcined, cooled and ground to obtain Li-Al-Si vitrification precursor powder.

[0010] S4: Pretreated coal gangue is obtained by crushing and ball milling coal gangue, and pretreated steel slag is obtained by crushing and ball milling steel slag. The pretreated coal gangue, fly ash, pretreated steel slag, core-shell structure thermal conductivity enhancer and Li-Al-Si vitrification precursor powder are placed in a mixer and dry-mixed to obtain dry material. A composite alkali-boron activator solution is added and wet-mixed to obtain a mixture. The mixture is placed in a mold, pressed and demolded to obtain a green blank. The green blank is heat-treated and then naturally cooled to obtain a high-temperature solid thermal storage material based on industrial solid waste.

[0011] As a preferred technical solution of the present invention, in step S1, the mass ratio of sodium hydroxide to deionized water is 1:(8-12), for example, it can be 1:8.0, 1:8.4, 1:8.8, 1:9.2, 1:9.6, 1:10.0, 1:10.4, 1:10.8, 1:11.2, 1:11.6 or 1:12.0, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0012] In some optional embodiments, the mass ratio of sodium hydroxide to sodium metaborate is 1:(0.2-0.5), for example, it can be 1:0.20, 1:0.23, 1:0.26, 1:0.29, 1:0.32, 1:0.35, 1:0.38, 1:0.41, 1:0.44, 1:0.47 or 1:0.50, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0013] In some alternative embodiments, the modulus of the water glass is 2.6-3.3, for example, it can be 2.60, 2.67, 2.74, 2.81, 2.88, 2.95, 3.02, 3.09, 3.16, 3.23 or 3.30, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0014] In some optional embodiments, the mass fraction of water glass in the silicon source is 50-70%, for example, it can be 50%, 52%, 54%, 56%, 58%, 60%, 62%, 64%, 66%, 68% or 70%, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0015] In some optional embodiments, the mass ratio of sodium hydroxide to silicon source is 1:(0.5-1.2), for example, it can be 1:0.50, 1:0.57, 1:0.64, 1:0.71, 1:0.78, 1:0.85, 1:0.92, 1:0.99, 1:1.06, 1:1.13 or 1:1.20, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0016] As a preferred technical solution of the present invention, in step S2, the volume ratio of anhydrous ethanol to deionized water in the mixed solvent is (15-25):(3-5), for example, it can be (15, 16, 17, 18, 19, 20, 21, 22, 23, 24 or 25):(3.0, 3.2, 3.4, 3.6, 3.8, 4.0, 4.2, 4.4, 4.6, 4.8 or 5.0), but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0017] In some alternative embodiments, the molar ratio of tetraethyl orthosilicate to phosphoric acid is 1:(0.1-0.3), for example, it can be 1:0.10, 1:0.12, 1:0.14, 1:0.16, 1:0.18, 1:0.20, 1:0.22, 1:0.24, 1:0.26, 1:0.28 or 1:0.30, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0018] In some optional embodiments, the volume ratio of deionized water to tetraethyl orthosilicate is (3-5):1, for example, it can be 3.0:1, 3.2:1, 3.4:1, 3.6:1, 3.8:1, 4.0:1, 4.2:1, 4.4:1, 4.6:1, 4.8:1 or 5.0:1, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0019] In some optional embodiments, the mass fraction of polyvinylpyrrolidone in the phosphorus-silicate precursor sol is 0.5-1.0 wt.%, for example, it can be 0.50 wt.%, 0.55 wt.%, 0.60 wt.%, 0.65 wt.%, 0.70 wt.%, 0.75 wt.%, 0.80 wt.%, 0.85 wt.%, 0.90 wt.%, 0.95 wt.%, or 1.00 wt.%, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0020] In some optional embodiments, the particle size of the metallurgical coke powder is 10-50 μm, for example, it can be 10 μm, 14 μm, 18 μm, 22 μm, 26 μm, 30 μm, 34 μm, 38 μm, 42 μm, 46 μm or 50 μm, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0021] In some optional embodiments, the mass ratio of metallurgical coke powder to tetraethyl orthosilicate is (2-4):1, for example, it can be 2.0:1, 2.2:1, 2.4:1, 2.6:1, 2.8:1, 3.0:1, 3.2:1, 3.4:1, 3.6:1, 3.8:1 or 4.0:1, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0022] As a preferred technical solution of the present invention, in step S3, the mass ratio of lithium carbonate, kaolin and quartz powder is 1:(3.3-3.7):(1.5-1.7), for example, it can be 1:(3.30, 3.34, 3.38, 3.42, 3.46, 3.50, 3.54, 3.58, 3.62, 3.66 or 3.70):(1.50, 1.52, 1.54, 1.56, 1.58, 1.60, 1.62, 1.64, 1.66, 1.68 or 1.70), but it is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0023] In some optional embodiments, the calcination temperature of the mixed powder is 700-800°C, for example, 700°C, 710°C, 720°C, 730°C, 740°C, 750°C, 760°C, 770°C, 780°C, 790°C or 800°C, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0024] In some optional embodiments, the calcination time of the mixed powder is 1-2 hours, for example, it can be 1.0 hours, 1.1 hours, 1.2 hours, 1.3 hours, 1.4 hours, 1.5 hours, 1.6 hours, 1.7 hours, 1.8 hours, 1.9 hours or 2.0 hours, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0025] As a preferred technical solution of the present invention, in step S4, the dry mixing time is 5-10 min, for example, it can be 5.0 min, 5.5 min, 6.0 min, 6.5 min, 7.0 min, 7.5 min, 8.0 min, 8.5 min, 9.0 min, 9.5 min or 10.0 min, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0026] In some optional embodiments, the mass ratio of the pretreated coal gangue, fly ash, pretreated steel slag, core-shell structure thermal conductivity enhancer, and Li-Al-Si vitrification precursor powder is (30-60):(20-40):(10-30):(8-15):(3-8), for example, it can be (30, 33, 36, 39, 42, 45, 48, 51, 54, 57 or 60):(20, 22, 24, 26, 28, 30, 32, 34, 36, 38 or 4 0):(10, 12, 14, 16, 18, 20, 22, 24, 26, 28 or 30):(8.0, 8.7, 9.4, 10.1, 10.8, 11.5, 12.2, 12.9, 13.6, 14.3 or 15.0):(3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5 or 8.0), but not limited to the listed values; other unlisted values ​​within this range also apply.

[0027] In some optional embodiments, the wet stirring time is 10-15 min, for example, it can be 10.0 min, 10.5 min, 11.0 min, 11.5 min, 12.0 min, 12.5 min, 13.0 min, 13.5 min, 14.0 min, 14.5 min or 15.0 min, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0028] In some optional embodiments, the amount of the composite alkali-boron activator solution added is 10-18% of the dry material mass, for example, it can be 10.0%, 10.8%, 11.6%, 12.4%, 13.2%, 14.0%, 14.8%, 15.6%, 16.4%, 17.2% or 18.0%, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0029] In some alternative embodiments, the holding pressure is 10-25 MPa, for example, it can be 10.0 MPa, 11.5 MPa, 13.0 MPa, 14.5 MPa, 16.0 MPa, 17.5 MPa, 19.0 MPa, 20.5 MPa, 22.0 MPa, 23.5 MPa or 25.0 MPa, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0030] In some optional embodiments, the pressure holding time is 30-60s, for example, it can be 30s, 33s, 36s, 39s, 42s, 45s, 48s, 51s, 54s, 57s or 60s, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0031] In some alternative embodiments, the first heating rate of the green body heat treatment is 3-5°C / min, for example, it can be 3.0°C / min, 3.2°C / min, 3.4°C / min, 3.6°C / min, 3.8°C / min, 4.0°C / min, 4.2°C / min, 4.4°C / min, 4.6°C / min, 4.8°C / min or 5.0°C / min, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0032] In some optional embodiments, the first temperature of the green body heat treatment is 850-900°C, for example, it can be 850°C, 855°C, 860°C, 865°C, 870°C, 875°C, 880°C, 885°C, 890°C, 895°C or 900°C, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0033] In some optional embodiments, the green body is held at a first temperature for 1-2 hours, for example, for 1.0h, 1.1h, 1.2h, 1.3h, 1.4h, 1.5h, 1.6h, 1.7h, 1.8h, 1.9h or 2.0h, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0034] In some optional embodiments, the second heating rate of the green body heat treatment is 5-8°C / min, for example, it can be 5.0°C / min, 5.3°C / min, 5.6°C / min, 5.9°C / min, 6.2°C / min, 6.5°C / min, 6.8°C / min, 7.1°C / min, 7.4°C / min, 7.7°C / min or 8.0°C / min, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0035] In some optional embodiments, the second temperature of the green body heat treatment is 1100-1210°C, for example, it can be 1100°C, 1111°C, 1122°C, 1133°C, 1144°C, 1155°C, 1166°C, 1177°C, 1188°C, 1199°C or 1210°C, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0036] In some alternative embodiments, the green body is held at a second temperature for 2-4 hours, for example, for 2.0 hours, 2.2 hours, 2.4 hours, 2.6 hours, 2.8 hours, 3.0 hours, 3.2 hours, 3.4 hours, 3.6 hours, 3.8 hours, or 4.0 hours, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0037] In some optional embodiments, the third cooling rate of the green body heat treatment is 5-10℃ / min, for example, it can be 5.0℃ / min, 5.5℃ / min, 6.0℃ / min, 6.5℃ / min, 7.0℃ / min, 7.5℃ / min, 8.0℃ / min, 8.5℃ / min, 9.0℃ / min, 9.5℃ / min or 10.0℃ / min, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0038] In some optional embodiments, the third temperature of the green body heat treatment is 820-860°C, for example, it can be 820°C, 824°C, 828°C, 832°C, 836°C, 840°C, 844°C, 848°C, 852°C, 856°C or 860°C, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0039] In some alternative embodiments, the green body is held at a third temperature for 1-3 hours, for example, for 1.0h, 1.2h, 1.4h, 1.6h, 1.8h, 2.0h, 2.2h, 2.4h, 2.6h, 2.8h or 3.0h, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0040] Secondly, the present invention provides a high-temperature solid thermal storage material based on industrial solid waste.

[0041] This application introduces three synergistic functional additives to transform inexpensive industrial solid waste into high-performance high-temperature solid thermal storage materials, thereby solving the fundamental problems of low inherent thermal conductivity, poor high-temperature strength, and insufficient thermal shock stability.

[0042] This application prepares a composite alkali-boron activator, which functions as both a low-temperature binder and a high-temperature flux in the system. First, at low and room temperatures, the activator acts as an initiator for geopolymer reactions. Sodium hydroxide provides an alkaline environment, which depolymerizes the amorphous aluminosilicate network in industrial solid waste (especially fly ash), releasing active ionic clusters. Simultaneously, the silicon sources (water glass and silica sol) added to the activator supplement soluble silicon species. These silicon and aluminum ions undergo condensation reactions under alkaline conditions, forming a cross-linked aluminosilicate hydrogel three-dimensional network. After drying, this network can bind loose solid waste particles into a green body with sufficient handling and processing strength, laying the structural foundation for subsequent high-temperature processing. Second, during the high-temperature sintering stage, the activator transforms into a liquid-phase sintering flux. Sodium metaborate and sodium ions can form a low-melting-point sodium boroaluminosilicate glass phase, accelerating atomic diffusion and mass migration. By effectively filling the pores between particles, it promotes densification of the material at lower temperatures. This not only reduces sintering energy consumption, but also provides a medium environment for the subsequent generation and distribution of other functional phases.

[0043] This application prepares a core-shell structured thermal conductivity enhancer to construct a highly efficient and stable three-dimensional thermal conductivity network within the matrix, thereby improving the shortcomings of traditional materials' thermal conductivity. The core of the enhancer is composed of highly thermally conductive metallurgical coke powder, which forms the basis of the thermal conductivity pathway. However, carbon materials are easily oxidized in high-temperature air, so a dense inorganic shell is introduced to protect them. The coke powder is uniformly dispersed in a polar sol through the steric hindrance effect of the nonionic surfactant polyvinylpyrrolidone. Tetraethyl orthosilicate undergoes acid-catalyzed hydrolysis and condensation, depositing a phosphorus-silicate precursor coating layer on the surface of the coke powder. In the first stage of subsequent heat treatment, this precursor shell layer undergoes a glass transition, forming a dense protective layer that isolates the carbon core from external oxygen, thus preventing the carbon core from being oxidized during subsequent sintering in a higher-temperature air atmosphere. This inorganic shell not only serves a protective function, but also has a certain degree of fluidity at high temperatures, enabling it to form good wetting and interfacial bonding with the surrounding matrix. This ensures that heat can be efficiently transferred from the matrix to the carbon core, and then rapidly conducted to the entire material through the carbon core network.

[0044] This application synthesizes Li-Al-Si vitrified precursor powder to address the poor thermal shock stability of the matrix material caused by thermal expansion mismatch. The Li-Al-Si vitrified precursor powder was prepared by mixing and reacting lithium carbonate, kaolin, and quartz powder. During the cooling stage after sintering, when the entire system enters the third temperature range, the Li-Al-Si vitrified precursor powder induces the precipitation of spodumene microcrystals in the surrounding glassy phase. These microcrystals undergo micro-expansion as the matrix cools and contracts, effectively passivating and deflecting crack tips and inhibiting microcrack propagation. This improves the macroscopic thermal shock resistance of the material, enabling it to withstand long-term, severe storage / release temperature cycling.

[0045] Synergistic effects also exist in this application. The low-temperature bonding effect provided by the composite alkali-boron activator enables the formation of green bodies containing core-shell thermal conductivity enhancers and Li-Al-Si vitrification precursor powders. During the high-temperature sintering stage, it acts as a liquid-phase sintering flux, creating conditions for the fusion of the shell layer of the core-shell thermal conductivity enhancer with the matrix and for the microcrystallization induced by the Li-Al-Si vitrification precursor powder. Secondly, the introduction of the composite alkali-boron activator leads to a decrease in sintering temperature, which, combined with the nitrogen protection in the first stage of the heat treatment process, ensures that the carbon core of the core-shell thermal conductivity enhancer is not oxidized before the shell layer densifies, achieving synergy between low-temperature sintering and the construction of the thermal conductivity network. During the cooling stage, the glass phase formed by the reaction of the composite alkali-boron activator and solid waste becomes the substrate for the Li-Al-Si vitrification precursor powder to function. Lithium spodumene microcrystals with low expansion coefficients induced by Li-Al-Si vitrification precursor powder are embedded and pinned between the thermally conductive network constructed by the core-shell structure thermal conductivity enhancer and the solid waste skeleton, achieving synergistic effects of thermal conductivity pathway and mechanical toughening. Finally, through reaction sintering and microcrystallization, a multiphase composite material with solid waste as the skeleton, refractory ceramic phase bonding, internally penetrating thermally conductive network, and toughened by low expansion matching and crack pinning is prepared, thereby improving thermal storage performance and mechanical stability.

[0046] Thirdly, the present invention provides a thermal storage reactor, which includes a thermal storage reactor body, an insulation layer inside the thermal storage reactor body, and a thermal storage bed inside the insulation layer. The thermal storage bed is made of the high-temperature solid thermal storage material based on industrial solid waste. Heat exchange fluid channels are uniformly arranged inside the thermal storage bed. One end of the heat exchange fluid channel passes through the thermal storage bed, the insulation layer and the thermal storage reactor body in sequence and is connected to the inlet header. The other end passes through the thermal storage bed, the insulation layer and the thermal storage reactor body in sequence and is connected to the outlet header.

[0047] As a preferred technical solution of the present invention, the thermal storage reactor body is a hollow, sealed container or cavity constructed of refractory bricks.

[0048] As a preferred embodiment of the present invention, the fluid used for heat exchange in the heat exchange fluid channel is one or more of air, nitrogen and carbon dioxide.

[0049] As a preferred embodiment of the present invention, the heat exchange fluid channel is a high-temperature resistant alloy steel pipe.

[0050] As a preferred embodiment of the present invention, the insulation layer is constructed from ceramic fiber modules.

[0051] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0052] The composite alkali-boron activator prepared in this application has a dual function. At low temperatures, it acts as an initiator for geopolymer reactions, activating solid waste raw materials in a strongly alkaline environment to form a gel network with adhesive properties, thereby solidifying loose powder into a green body with sufficient strength. During high-temperature sintering, it transforms into a highly efficient flux, with its boron and sodium elements forming a low-melting-point glass phase. By promoting mass migration and filling pores, it achieves material densification at lower temperatures.

[0053] This application utilizes a core-shell structured thermal conductivity enhancer to construct a stable three-dimensional thermal conductivity network, thereby improving the thermal conductivity of the material. By coating the surface of coke powder with a precursor and vitrifying it during heat treatment, a dense outer shell is formed. This shell not only effectively isolates oxygen and prevents the carbon core from being oxidized during high-temperature sintering, but also forms a good interfacial bond with the surrounding matrix. This structure ensures that heat can be transferred from the matrix to the carbon core, and then rapidly conducted through the carbon core network.

[0054] This application enhances the thermal shock resistance of materials by introducing Li-Al-Si vitrification precursor powder. During the cooling stage after sintering, it induces the precipitation of spodumene microcrystals with low thermal expansion characteristics in the surrounding glassy phase. The micro-compressive stress generated by these microcrystals during the cooling and contraction of the matrix effectively inhibits the propagation of microcracks, thereby endowing the material with excellent ability to withstand long-term severe temperature cycling.

[0055] In this application, the composite alkali-boron activator ensures the formation of complex preforms through low-temperature bonding and transforms into a liquid phase at high temperatures to provide a mass transfer environment for subsequent reactions. Secondly, its low-temperature sintering effect, combined with nitrogen protection in the process, protects the carbon cores of the thermally conductive agent from oxidation, achieving a complete thermal network structure. During the cooling stage, low-expansion matching and crack pinning induced by the Li-Al-Si vitrification precursor powder precipitate in the glass phase, effectively pinning and strengthening the composite structure composed of the thermal network and solid waste framework. This synergistic effect enhances the material's thermal storage performance and mechanical stability. Attached Figure Description

[0056] Figure 1The structural schematic diagram of the thermal storage reactor provided in this application.

[0057] Reference numerals in the attached drawings: 1. Thermal storage reactor body; 2. Insulation layer; 3. Thermal storage bed; 4. Heat exchange fluid channel; 5. Inlet header; 6. Outlet header. Detailed Implementation

[0058] The technical solutions of the present invention will be described in detail below with reference to specific embodiments and accompanying drawings. The embodiments described herein are specific implementations of the present invention, used to illustrate the concept of the present invention; these descriptions are explanatory and exemplary, and should not be construed as limiting the implementation methods or the scope of protection of the present invention. In addition to the embodiments described herein, those skilled in the art can employ other obvious technical solutions based on the content disclosed in the claims and specification of this application. These technical solutions include any obvious substitutions and modifications made to the embodiments described herein.

[0059] The chemical reagents used in the embodiments and comparative examples of this invention are all commercially available products and have not undergone further purification or processing.

[0060] Example 1

[0061] This embodiment provides a high-temperature solid thermal storage material based on industrial solid waste and its preparation method. The preparation method of the high-temperature solid thermal storage material based on industrial solid waste specifically includes the following steps:

[0062] S1: Sodium hydroxide and deionized water are mixed at a mass ratio of 1:10 to obtain dispersion A. Sodium metaborate is added to obtain dispersion B, wherein the mass ratio of sodium hydroxide to sodium metaborate is 1:0.4. Water glass with a modulus of 3.0 is mixed with silica sol to obtain a silicon source, wherein the mass fraction of water glass in the silicon source is 65%. The silicon source is added to dispersion B, wherein the mass ratio of sodium hydroxide to silicon source is 1:1.0. After stirring evenly, a composite alkali-boron activator solution is obtained.

[0063] S2: Tetraethyl orthosilicate and phosphoric acid are dispersed in a mixed solvent to obtain a preliminary phosphorus-silicate precursor sol. The volume ratio of anhydrous ethanol to deionized water in the mixed solvent is 22:4, the molar ratio of tetraethyl orthosilicate to phosphoric acid is 1:0.25, and the volume ratio of deionized water to tetraethyl orthosilicate is 4:1. Polyvinylpyrrolidone is added to obtain a phosphorus-silicate precursor sol. The mass fraction of polyvinylpyrrolidone in the phosphorus-silicate precursor sol is 0.8 wt.%. Metallurgical coke powder with a particle size of 40 μm is dispersed in the phosphorus-silicate precursor sol, wherein the mass ratio of metallurgical coke powder to tetraethyl orthosilicate is 3.5:1. The mixture is stirred, dried, and ground to obtain a core-shell structure thermal conductivity enhancer.

[0064] S3: Lithium carbonate, kaolin and quartz powder are uniformly mixed to obtain a mixed powder, wherein the mass ratio of lithium carbonate, kaolin and quartz powder is 1:3.5:1.6. The mixture is calcined at 780℃ for 1.8h, cooled and then ground to obtain Li-Al-Si vitrification precursor powder.

[0065] S4: Pretreated coal gangue is obtained by crushing and ball milling coal gangue, and pretreated steel slag is obtained by crushing and ball milling steel slag. The pretreated coal gangue, fly ash, pretreated steel slag, core-shell structure thermal conductivity enhancer, and Li-Al-Si vitrification precursor powder are placed in a mixer and dry-mixed for 8 minutes to obtain a dry material. The mass ratio of the pretreated coal gangue, fly ash, pretreated steel slag, core-shell structure thermal conductivity enhancer, and Li-Al-Si vitrification precursor powder is 55:25:15:10:5. A composite alkali-boron activator solution is added and wet-mixed for 12 minutes to obtain a mixed material. The solution was added at 15% of the dry material mass. The mixture was placed in a mold and pressed at 22 MPa for 50 seconds before demolding to obtain a green blank. After heat treatment, it was naturally cooled to obtain a high-temperature solid thermal storage material based on industrial solid waste. The first heating rate of the heat treatment was 4.5℃ / min, the first treatment temperature was 880℃ under a nitrogen atmosphere, and the time was 1.8h. The second heating rate was 7℃ / min, the second treatment temperature was 1150℃ under an air atmosphere, and the time was 3.5h. The third cooling rate was 8℃ / min, the third treatment temperature was 845℃, and the time was 2.5h.

[0066] Example 2

[0067] This embodiment provides a high-temperature solid thermal storage material based on industrial solid waste and its preparation method. The preparation method of the high-temperature solid thermal storage material based on industrial solid waste specifically includes the following steps:

[0068] S1: Sodium hydroxide and deionized water are mixed at a mass ratio of 1:8 to obtain dispersion A. Sodium metaborate is added to obtain dispersion B, wherein the mass ratio of sodium hydroxide to sodium metaborate is 1:0.2. Water glass with a modulus of 2.6 is mixed with silica sol to obtain a silicon source, wherein the mass fraction of water glass in the silicon source is 50%. The silicon source is added to dispersion B, wherein the mass ratio of sodium hydroxide to silicon source is 1:0.5. After stirring evenly, a composite alkali-boron activator solution is obtained.

[0069] S2: Tetraethyl orthosilicate and phosphoric acid are dispersed in a mixed solvent to obtain a preliminary phosphorus-silicate precursor sol. The volume ratio of anhydrous ethanol to deionized water in the mixed solvent is 15:3, the molar ratio of tetraethyl orthosilicate to phosphoric acid is 1:0.1, and the volume ratio of deionized water to tetraethyl orthosilicate is 3:1. Polyvinylpyrrolidone is added to obtain a phosphorus-silicate precursor sol. The mass fraction of polyvinylpyrrolidone in the phosphorus-silicate precursor sol is 0.5 wt.%. Metallurgical coke powder with a particle size of 10 μm is dispersed in the phosphorus-silicate precursor sol, wherein the mass ratio of metallurgical coke powder to tetraethyl orthosilicate is 2:1. The mixture is stirred, dried, and ground to obtain a core-shell structure thermal conductivity enhancer.

[0070] S3: Lithium carbonate, kaolin and quartz powder are uniformly mixed to obtain a mixed powder, wherein the mass ratio of lithium carbonate, kaolin and quartz powder is 1:3.3:1.5. The mixture is calcined at 700℃ for 1 hour, cooled and then ground to obtain Li-Al-Si vitrification precursor powder.

[0071] S4: Pretreated coal gangue is obtained by crushing and ball milling coal gangue, and pretreated steel slag is obtained by crushing and ball milling steel slag. The pretreated coal gangue, fly ash, pretreated steel slag, core-shell structure thermal conductivity enhancer, and Li-Al-Si vitrification precursor powder are placed in a mixer and dry-mixed for 5 minutes to obtain a dry material. The mass ratio of the pretreated coal gangue, fly ash, pretreated steel slag, core-shell structure thermal conductivity enhancer, and Li-Al-Si vitrification precursor powder is 30:40:10:8:3. A composite alkali-boron activator solution is added and wet-mixed for 15 minutes to obtain a mixed material. The activator solution was added at 10% of the dry material mass. The mixture was placed in a mold and pressed at 10 MPa for 30 seconds before demolding to obtain a green blank. After heat treatment, it was naturally cooled to obtain a high-temperature solid thermal storage material based on industrial solid waste. The first heating rate of the heat treatment was 3℃ / min, the first treatment temperature was 850℃ under a nitrogen atmosphere, and the time was 1h. The second heating rate was 5℃ / min, the second treatment temperature was 1100℃ under an air atmosphere, and the time was 2h. The third cooling rate was 5℃ / min, the third treatment temperature was 820℃, and the time was 1h.

[0072] Example 3

[0073] This embodiment provides a high-temperature solid thermal storage material based on industrial solid waste and its preparation method. The preparation method of the high-temperature solid thermal storage material based on industrial solid waste specifically includes the following steps:

[0074] S1: Sodium hydroxide and deionized water are mixed at a mass ratio of 1:11 to obtain dispersion A. Sodium metaborate is added to obtain dispersion B, wherein the mass ratio of sodium hydroxide to sodium metaborate is 1:0.3. Water glass with a modulus of 2.8 is mixed with silica sol to obtain a silicon source, wherein the mass fraction of water glass in the silicon source is 60%. The silicon source is added to dispersion B, wherein the mass ratio of sodium hydroxide to silicon source is 1:0.8. After stirring evenly, a composite alkali-boron activator solution is obtained.

[0075] S2: Tetraethyl orthosilicate and phosphoric acid are dispersed in a mixed solvent to obtain a preliminary phosphorus-silicate precursor sol. The volume ratio of anhydrous ethanol to deionized water in the mixed solvent is 18:3.5, the molar ratio of tetraethyl orthosilicate to phosphoric acid is 1:0.15, and the volume ratio of deionized water to tetraethyl orthosilicate is 4.5:1. Polyvinylpyrrolidone is added to obtain a phosphorus-silicate precursor sol. The mass fraction of polyvinylpyrrolidone in the phosphorus-silicate precursor sol is 0.6 wt.%. Metallurgical coke powder with a particle size of 20 μm is dispersed in the phosphorus-silicate precursor sol, wherein the mass ratio of metallurgical coke powder to tetraethyl orthosilicate is 2.5:1. The mixture is stirred, dried, and ground to obtain a core-shell structure thermal conductivity enhancer.

[0076] S3: Lithium carbonate, kaolin and quartz powder are uniformly mixed to obtain a mixed powder, wherein the mass ratio of lithium carbonate, kaolin and quartz powder is 1:3.6:1.65. The mixture is calcined at 720℃ for 1.2h, cooled and then ground to obtain Li-Al-Si vitrification precursor powder.

[0077] S4: Pretreated coal gangue is obtained by crushing and ball milling coal gangue, and pretreated steel slag is obtained by crushing and ball milling steel slag. The pretreated coal gangue, fly ash, pretreated steel slag, core-shell structure thermal conductivity enhancer, and Li-Al-Si vitrification precursor powder are placed in a mixer and dry-mixed for 6 minutes to obtain a dry material. The mass ratio of the pretreated coal gangue, fly ash, pretreated steel slag, core-shell structure thermal conductivity enhancer, and Li-Al-Si vitrification precursor powder is 60:20:30:15:8. A composite alkali-boron activator solution is added and wet-mixed for 14 minutes to obtain a mixed material. The solution was added at 12% of the dry material mass. The mixture was placed in a mold and pressed at 15 MPa for 40 seconds before demolding to obtain a green body. After heat treatment, it was naturally cooled to obtain a high-temperature solid thermal storage material based on industrial solid waste. The first heating rate of the heat treatment was 3.5℃ / min, the first treatment temperature was 860℃ under a nitrogen atmosphere, and the time was 1.2h. The second heating rate was 6℃ / min, the second treatment temperature was 1180℃ under an air atmosphere, and the time was 2.5h. The third cooling rate was 6℃ / min, the third treatment temperature was 830℃, and the time was 1.5h.

[0078] Example 4

[0079] This embodiment provides a high-temperature solid thermal storage material based on industrial solid waste and its preparation method. The preparation method of the high-temperature solid thermal storage material based on industrial solid waste specifically includes the following steps:

[0080] S1: Sodium hydroxide and deionized water are mixed at a mass ratio of 1:12 to obtain dispersion A. Sodium metaborate is added to obtain dispersion B, wherein the mass ratio of sodium hydroxide to sodium metaborate is 1:0.5. Water glass with a modulus of 3.3 is mixed with silica sol to obtain a silicon source, wherein the mass fraction of water glass in the silicon source is 70%. The silicon source is added to dispersion B, wherein the mass ratio of sodium hydroxide to silicon source is 1:1.2. After stirring evenly, a composite alkali-boron activator solution is obtained.

[0081] S2: Tetraethyl orthosilicate and phosphoric acid are dispersed in a mixed solvent to obtain a preliminary phosphorus-silicate precursor sol. The volume ratio of anhydrous ethanol to deionized water in the mixed solvent is 25:5, the molar ratio of tetraethyl orthosilicate to phosphoric acid is 1:0.3, and the volume ratio of deionized water to tetraethyl orthosilicate is 5:1. Polyvinylpyrrolidone is added to obtain a phosphorus-silicate precursor sol. The mass fraction of polyvinylpyrrolidone in the phosphorus-silicate precursor sol is 1.0 wt.%. Metallurgical coke powder with a particle size of 50 μm is dispersed in the phosphorus-silicate precursor sol, wherein the mass ratio of metallurgical coke powder to tetraethyl orthosilicate is 4:1. The mixture is stirred, dried, and ground to obtain a core-shell structure thermal conductivity enhancer.

[0082] S3: Lithium carbonate, kaolin and quartz powder are uniformly mixed to obtain a mixed powder, wherein the mass ratio of lithium carbonate, kaolin and quartz powder is 1:3.7:1.7. The mixture is calcined at 800℃ for 2 hours, cooled and then ground to obtain Li-Al-Si vitrification precursor powder.

[0083] S4: Pretreated coal gangue is obtained by crushing and ball milling coal gangue, and pretreated steel slag is obtained by crushing and ball milling steel slag. The pretreated coal gangue, fly ash, pretreated steel slag, core-shell structure thermal conductivity enhancer, and Li-Al-Si vitrification precursor powder are placed in a mixer and dry-mixed for 10 minutes to obtain a dry material. The mass ratio of the pretreated coal gangue, fly ash, pretreated steel slag, core-shell structure thermal conductivity enhancer, and Li-Al-Si vitrification precursor powder is 40:30:20:12:6. A composite alkali-boron activator solution is added and wet-mixed for 10 minutes to obtain a mixed material. The amount of boron activator solution added is 18% of the dry material mass. The mixture is placed in a mold, held under pressure at 25 MPa for 60 s, and then demolded to obtain a green blank. After heat treatment, it is naturally cooled to obtain a high-temperature solid thermal storage material based on industrial solid waste. The first heating rate of the heat treatment is 5℃ / min, the first treatment temperature is 900℃ under nitrogen atmosphere, and the time is 2h; the second heating rate is 8℃ / min, the second treatment temperature is 1210℃ under air atmosphere, and the time is 4h; the third cooling rate is 10℃ / min, the third treatment temperature is 860℃, and the time is 3h.

[0084] Example 5

[0085] like Figure 1 As shown, this embodiment provides a thermal storage stack, which includes a thermal storage stack body 1, an insulation layer 2 inside the thermal storage stack body 1, and a thermal storage bed 3 inside the insulation layer 2. The thermal storage bed 3 is made of the high-temperature solid thermal storage material based on industrial solid waste. Heat exchange fluid channels 4 are uniformly arranged inside the thermal storage bed 3. One end of the heat exchange fluid channel 4 passes through the thermal storage bed 3, the insulation layer 2 and the thermal storage stack body 1 in sequence and is connected to the inlet header 5. The other end passes through the thermal storage bed 3, the insulation layer 2 and the thermal storage stack body 1 in sequence and is connected to the outlet header 6.

[0086] The thermal storage reactor body 1 is a hollow, sealed container or cavity constructed of refractory bricks. The fluid used for heat exchange in the heat exchange fluid channel 4 is one or more of air, nitrogen, and carbon dioxide. The heat exchange fluid channel 4 is a high-temperature resistant alloy steel pipe. The insulation layer 2 is constructed of ceramic fiber modules.

[0087] Thermal storage process: Air is heated to 750°C using off-peak electricity at night, and then delivered into the thermal storage reactor body 1 via a fan and inlet header 5. The hot air flows through the heat exchange fluid channel 4, transferring heat to the surrounding thermal storage bed 3, and then cools down to approximately 150°C before being discharged from the outlet header 6. After 8 hours of continuous heating, the core temperature of the thermal storage reactor body 1 is raised to over 700°C.

[0088] Heat release process: During peak electricity consumption periods in the daytime, ambient temperature air is pumped into the thermal storage stack from the inlet header 5. The cold air flows through the high-temperature thermal storage bed 3 and is heated to over 650°C. The high-temperature air discharged from the outlet header 6 drives the steam generator to produce steam, which in turn drives the turbine unit to generate electricity or is directly used for district heating.

[0089] Comparative Example 1

[0090] This comparative example provides a high-temperature solid thermal energy storage material based on industrial solid waste. The difference from Example 1 is that the silicon source in S1 is used to replace the composite alkali-boron activator solution, while the other operating steps and process parameters are exactly the same as in Example 1.

[0091] Comparative Example 2

[0092] This comparative example provides a high-temperature solid thermal storage material based on industrial solid waste. The difference from Example 1 is that untreated metallurgical coke powder is used to replace the core-shell structure thermal conductivity enhancer. Other operating steps and process parameters are exactly the same as in Example 1.

[0093] Comparative Example 3

[0094] This comparative example provides a high-temperature solid thermal energy storage material based on industrial solid waste. The difference from Example 1 is that Li-Al-Si vitrification precursor powder is not added, while other operating steps and process parameters are exactly the same as in Example 1.

[0095] Comparative Example 4

[0096] This comparative example provides a high-temperature solid thermal storage material based on industrial solid waste. The difference from Example 1 is that in the heat treatment step S4, the material is kept at a first treatment temperature in an air atmosphere. Other operating steps and process parameters are exactly the same as in Example 1.

[0097] The performance of the high-temperature solid thermal energy storage materials based on industrial solid waste in Examples 1-4 and Comparative Examples 1-4 was tested, and the specific process is as follows:

[0098] The volumetric heat capacity was calculated based on the specific heat capacity of the sample tested according to ASTM E1269 and the measured density.

[0099] The thermal conductivity was calculated based on the thermal diffusivity of the test sample according to ASTM E1461.

[0100] The compressive strength of the sample was tested according to GB / T1964-1996;

[0101] Thermal shock resistance: The sample was heated to 800℃ in a high-temperature furnace and held for 1 hour. It was then quickly removed and forced to cool to room temperature in the air, which constituted one thermal cycle. The test was repeated 100 times to test its compressive strength. The retention rate was calculated by comparing the initial compressive strength with the test results.

[0102] The test results are shown in Table 1.

[0103] Table 1. Performance test results of high-temperature solid thermal storage materials based on industrial solid waste prepared in Examples 1-4 and Comparative Examples 1-4

[0104]

[0105] As can be seen from the test results of Example 1 and Comparative Example 1 in Table 1, when a silicon source is used to replace the composite alkali-boron activator solution, the strong alkali activation of the composite alkali-boron activator and the fluxing effect of boron are lacking, the sintering driving force is weakened. At the same temperature, the densification degree of the material decreases, the residual porosity is high, resulting in a decrease in density and strength, and thus a decrease in volumetric heat capacity and compressive strength. Although the internal thermal conductive network still exists, the overall thermal conductivity will decrease due to the non-dense matrix itself. The overall structure is loose and the strength is low. Under thermal stress, cracks are more likely to initiate and propagate from the pores, and the thermal shock resistance is reduced.

[0106] As shown in Table 1, the test results of Example 1 and Comparative Example 2 indicate that when untreated metallurgical coke powder is used to replace the core-shell structure thermal conductivity enhancer, the carbon core is oxidized and ablated during the high-temperature air sintering stage. This causes the thermal conductivity network to fail and leaves pores inside the material. This not only reduces thermal conductivity but also weakens the material's load-bearing capacity as a structural defect, leading to reduced compressive strength, density, and volumetric heat capacity. Although the material matrix remains relatively dense, the pores formed by oxidation act as stress concentration points, accelerating crack initiation and thus reducing its thermal shock resistance.

[0107] As shown in Table 1, the test results of Example 1 and Comparative Example 3 indicate that without the addition of Li-Al-Si vitrification precursor powder, the material cannot improve its thermal shock resistance through microcrystallization. Lacking the pinning and stress compensation effects of low thermal expansion spodumene microcrystals, the material becomes brittle. Under the enormous thermal stress generated by thermal cycling, microcracks will rapidly initiate and propagate, leading to a decline in its thermal shock resistance. Its initial volumetric heat capacity, thermal conductivity, and compressive strength may be comparable to or slightly higher than those of Example 1 due to the higher glass phase content.

[0108] As can be seen from the test results of Example 1 and Comparative Example 4 in Table 1, in the heat treatment step S4, the heat treatment was carried out at the first treatment temperature in an air atmosphere. Changing the nitrogen protection of the first stage heat treatment to an air atmosphere caused the carbon core to partially oxidize before the shell was fully densified. This resulted in partial damage to the heat-conducting network, leading to a decrease in thermal conductivity. The internal defects and pores caused by partial oxidation also resulted in a decrease in compressive strength and density, and a reduction in volumetric heat capacity.

[0109] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method for producing a high-temperature solid heat storage material based on industrial solid waste, characterized by, The preparation method comprises: S1: mixing sodium hydroxide and deionized water to obtain dispersion liquid A, adding sodium metaborate to obtain dispersion liquid B; the mass ratio of sodium hydroxide to sodium metaborate is 1:(0.2-0.5), mixing water glass and silica sol to obtain a silicon source, adding the silicon source into the dispersion liquid B, and the mass ratio of sodium hydroxide to the silicon source is 1:(0.5-1.2), and stirring uniformly to obtain a composite alkali-boron activator solution; S2: dispersing tetraethyl orthosilicate and phosphoric acid in a mixed solvent to obtain a preliminary phosphorus-silicate precursor sol, the mixed solvent is a mixed solvent of anhydrous ethanol and deionized water, adding polyvinylpyrrolidone to obtain a phosphorus-silicate precursor sol, dispersing metallurgical coke powder in the phosphorus-silicate precursor sol, stirring, drying, and grinding to obtain a core-shell structure thermal conductivity enhancer; the mass ratio of the metallurgical coke powder to the tetraethyl orthosilicate is (2-4):1; S3: uniformly mixing lithium carbonate, kaolin and quartz powder in a mass ratio of 1:(3.3-3.7):(1.5-1.7) to obtain a mixed powder, calcining at 700-800°C, and grinding after cooling to obtain a Li-Al-Si vitrification precursor powder; S4: crushing and ball milling coal gangue to obtain pretreated coal gangue, crushing and ball milling steel slag to obtain pretreated steel slag, placing the pretreated coal gangue, fly ash, pretreated steel slag, core-shell structure thermal conductivity enhancer and Li-Al-Si vitrification precursor powder in a stirrer to dry mix to obtain dry materials, the mass ratio of the pretreated coal gangue, fly ash, pretreated steel slag, core-shell structure thermal conductivity enhancer and Li-Al-Si vitrification precursor powder is (30-60):(20-40):(10-30):(8-15):(3-8); adding a composite alkali-boron activator solution to wet stir to obtain mixed materials, the addition amount of the composite alkali-boron activator solution is 10-18% of the mass of the dry materials, placing the mixed materials in a mold, pressing, and demolding to obtain a green body, heat treating the green body and naturally cooling to obtain an industrial solid waste-based high-temperature solid heat storage material, the first stage of the heat treatment of the green body is carried out under nitrogen protection, the first temperature of the heat treatment under the nitrogen atmosphere is 850-900°C, the first temperature rising rate is 3-5°C / min, and the holding time at the first temperature is 1-2h; the second temperature of the heat treatment under the air atmosphere is 1100-1210°C, the second temperature rising rate is 5-8°C / min, and the holding time at the second temperature is 2-4h; the third temperature is 820-860°C, the third temperature falling rate is 5-10°C / min, and the holding time at the third temperature is 1-3h.

2. The method of claim 1, wherein the high-temperature solid heat storage material based on industrial solid waste is prepared by the steps of: In S1: ​ The mass ratio of sodium hydroxide to deionized water is 1:(8-12).

3. The method according to claim 1, wherein the method is characterized by, In S1: The mass fraction of water glass in the silicon source is 50-70%.

4. The method according to claim 1, wherein the method is characterized by, In S2: The molar ratio of tetraethyl orthosilicate to phosphoric acid is 1:(0.1-0.3); The volume ratio of deionized water to tetraethyl orthosilicate is (3-5):1; The volume ratio of anhydrous ethanol to deionized water in the mixed solvent is (15-25):(3-5).

5. The method for preparing a high-temperature solid thermal storage material based on industrial solid waste according to claim 1, characterized in that, In S2: The mass fraction of polyvinylpyrrolidone in the phosphorus-silicate precursor sol is 0.5-1.0 wt.%. The particle size of the metallurgical coke powder is 10-50 μm.

6. A high temperature solid heat storage material based on industrial solid waste, characterized by, The preparation method according to any one of claims 1-5.

7. A thermal battery characterized by, The heat storage stack comprises a heat storage stack body (1), a heat preservation layer (2) is arranged in the heat storage stack body (1), a heat storage bed (3) is arranged in the heat preservation layer (2), the heat storage bed (3) is made of the high-temperature solid heat storage material based on industrial solid waste according to claim 6, the heat storage bed (3) is uniformly arranged with heat exchange fluid channels (4), one end of the heat exchange fluid channels (4) is sequentially connected with an inlet header (5) through the heat storage bed (3), the heat preservation layer (2) and the heat storage stack body (1), and the other end of the heat exchange fluid channels (4) is sequentially connected with an outlet header (6) through the heat storage bed (3), the heat preservation layer (2) and the heat storage stack body (1).

8. The heat storage stack according to claim 7, characterized in that, The heat storage stack body (1) is a hollow closed container or cavity built by refractory bricks; The fluid for heat exchange in the heat exchange fluid channels (4) is one or more of air, nitrogen and carbon dioxide; The heat exchange fluid channels (4) are high-temperature alloy steel pipes; The heat preservation layer (2) is built by ceramic fiber modules.

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