Solid heat storage structural body

Abstract

The invention relates to a solid heat storage structural body, which enables an electric heating wire as a heating unit to be arranged in an air through hole of a magnesium oxide brick, on one hand, an electric heating device can be directly used under high voltage of more than 10 kV, and on the other hand, air accommodated between the air through hole and the electric heating wire is used as an insulating medium, so that the solid heat storage structural body is formed. The insulativity of the solid heat storage structural body can be improved; moreover, by increasing the distance b between the air through holes and the carbon bricks and the shortest distance d between every two adjacent air through holes, the risk that current is conducted to the outside of the solid heat storage structural body by the carbon bricks can be reduced, and then the insulativity of the solid heat storage structural body can be further improved. Meanwhile, the outer layer of the magnesium oxide brick is coated with the heat storage unit composed of the carbon bricks, the heat storage performance of the solid heat storage structural body can be improved, and the heat exchange rate of the solid heat storage structural body can also be improved.

Description

Technical Field

[0001] The present disclosure relates to the field of heat storage, and in particular, to a solid heat storage structure. Background Art

[0002] Large factories such as industrial parks need to absorb a large amount of heat during the reproduction or manufacturing process. Large factories such as industrial parks usually use solid heat storage devices to convert air and water into hot air, hot water or steam, and then use the relevant heat by directly passing it into a heat-using device or by heat exchange. The existing solid heat storage device is equipped with an electric heating device and a heat storage device. During its use, the electric heating device is first powered on to generate heat, and the heat storage device absorbs the generated heat and gathers and stores the heat; then the air and / or water are passed through the solid heat storage device, which can be converted into hot air, hot water or steam.

[0003] The access voltage of large factories such as industrial parks is generally a high voltage of 10Kv. On the one hand, the rated voltage applicable to the electric heating device in the traditional solid heat storage device is basically 220V (single phase) / 380V (three phase). Therefore, it cannot be directly connected to the power distribution end of large factories such as industrial parks. It is necessary to add a transformer to reduce the high voltage to 220V (single phase) / 380V (three phase) before it can be transmitted to the electric heating device. The structure is complex, the installation and connection operations are cumbersome, the installation and construction time is long, the equipment occupies a large area, and the cost investment is high. On the other hand, the electric heating device in the traditional solid heat storage device is used under high voltage. Due to the poor insulation of the heat storage device, leakage will occur, which will increase the loss of electricity, high operating costs, and poor safety.

[0004] In addition, the heat storage capacity and thermal conductivity of traditional solid heat storage devices are not high. For example, patent CN202010347783.6 discloses an insulation test device and method for a high-temperature solid heat storage insulating lead-in sleeve. The heat storage material used is magnesium oxide, and the maximum heat storage temperature is 700°C. However, the thermal conductivity of magnesium oxide materials is currently very low (solid magnesium brick thermal conductivity ≤ 2W / mk), and the rapid storage and release performance of heat storage cannot be achieved, which greatly restricts the efficiency and stability of high-temperature steam production. Summary of the invention

[0005] The purpose of the present disclosure is to provide a solid heat storage structure to solve the problem that the electric heating device in the solid heat storage device in the prior art cannot be used for high voltage, and the solid heat storage device has poor insulation, poor heat storage performance and low heat exchange rate.

[0006] To achieve the above object, the present disclosure provides a solid heat storage structure, which includes: a heating unit including an electric heating wire; an insulating unit including magnesia bricks, and the magnesia bricks include air through-holes for accommodating air; the electric heating wire is disposed in the air through-holes of the magnesia bricks; a heat storage unit which is a carbon brick, and the heat storage unit is coated on the outer side of the insulating unit and adjacent two insulating units are separated by the heat storage unit; the shortest distance b between the air through-hole and the edge of the magnesia brick is 30 to 72 mm; the width c of the magnesia brick is 90 to 160 mm; the shortest distance d between adjacent two air through-holes is 140 to 210 mm.

[0007] Optionally, the material of the carbon brick includes flake graphite and amorphous carbon; the weight ratio of the flake graphite to the amorphous carbon is (3 to 4):(1 to 2), preferably (3.2 to 3.6):(1.2 to 1.6).

[0008] Optionally, the weight ratio of the carbon brick to the magnesia brick is (1 to 3):(1 to 2), preferably (1.5 to 2.5):(1.1 to 1.6).

[0009] Optionally, the solid heat storage structure is a column with a rectangular cross-section; the magnesia brick and the carbon brick are respectively columns with a rectangular cross-section; the extending direction of the air through-holes of the magnesia brick is the same as the axial direction of the solid heat storage structure, and preferably, the air through-holes are coaxially arranged with the magnesia brick.

[0010] Optionally, the shortest distance b between the air through-hole and the edge of the magnesia brick is 30 to 50 mm.

[0011] Optionally, the solid heat storage structure includes an intermediate composite layer, a first carbon brick layer and a second carbon brick layer; the intermediate composite layer includes multiple magnesia bricks and multiple carbon bricks; multiple carbon bricks are arranged at intervals along the radial direction of the solid heat storage structure, and between adjacent two carbon bricks, there is a magnesia brick; the first carbon brick layer and the second carbon brick layer are respectively formed by multiple carbon bricks laid flat along the radial direction of the solid heat storage structure; the first carbon brick layer and the second carbon brick layer are arranged on both sides of the intermediate composite layer.

[0012] Optionally, the shortest distance a between adjacent two magnesia bricks is 70 to 120 mm; the height of the magnesia brick is 110 to 150 mm; the shortest distance d between adjacent two air through-holes is 160 to 200 mm

[0013] Optionally, the shape of the electric heating wire is a cylinder; the extending direction of the air through-hole is the same as that of the electric heating wire; the ratio of the aperture of the air through-hole to the outer diameter of the electric heating wire is (1.2 to 3.5):1.

[0014] Optionally, the ratio of the volume of the air through-hole to the volume of the magnesia brick is (0.1 to 0.16):1.

[0015] Optionally, the heat storage temperature of the solid heat storage structure is above 900 °C; the material of the electric heating wire in the solid heat storage structure is an iron-chromium-aluminum alloy material, and the operating voltage of the electric heating wire is above 10 kV.

[0016] Through the above technical solution, in the present disclosure, the electric heating wire as the heating unit is arranged in the air through-hole of the magnesia brick. On the one hand, the electric heating device can be directly used at a high voltage above 10 kV. On the other hand, the air accommodated between the air through-hole and the electric heating wire can be used as an insulating medium to improve the insulation of the solid heat storage structure; and by increasing the distance b between the air through-hole and the carbon brick and the shortest distance d between two adjacent air through-holes, the risk of current being conducted by the carbon brick to the outside of the solid heat storage structure can be reduced, thereby further improving the insulation of the solid heat storage structure. At the same time, a heat storage unit composed of carbon bricks is coated on the outer layer of the magnesia brick, which can not only improve the heat storage performance of the solid heat storage structure, but also improve the heat exchange rate of the solid heat storage structure.

[0017] Other features and advantages of the present disclosure will be described in detail in the following specific implementation section. Brief Description of the Drawings

[0018] The drawings are used to provide a further understanding of the present disclosure, and constitute a part of the specification. They are used together with the following specific implementation to explain the present disclosure, but do not constitute a limitation to the present disclosure. In the drawings:

[0019] Figure 1 is a schematic cross-sectional view of a solid heat storage structure.

[0020] Figure 2 is a schematic view of a solid heat storage structure.

[0021] Description of the Reference Numerals

[0022] 1. Magnesia brick; 2. Carbon brick; 3. Air through-hole; 4. Electric heating wire; 5. First carbon brick layer; 6. Intermediate composite layer; 7. Second carbon brick layer. Detailed Description of the Invention

[0023] The following will describe in detail the specific embodiments of the present disclosure with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only for the purpose of illustrating and explaining the present disclosure, and are not intended to limit the present disclosure.

[0024] As Figure 1 shown, the present disclosure provides a solid heat storage structure, and the solid heat storage structure includes: a heating unit, the heating unit includes an electric heating wire; an insulating unit, the insulating unit includes a magnesia brick, and the magnesia brick includes air through holes for accommodating air; the electric heating wire is disposed in the air through holes of the magnesia brick; a heat storage unit, the heat storage unit is a carbon brick, the heat storage unit is coated on the outer side of the insulating unit and adjacent two insulating units are separated by the heat storage unit; the shortest distance b between the air through hole and the edge of the magnesia brick is 30 to 72 mm; the height c of the magnesia brick is 90 to 160 mm; the shortest distance d between adjacent two air through holes is 140 to 210 mm.

[0025] Through the above technical solution, in the present disclosure, the electric heating wire as the heating unit is disposed in the air through holes of the magnesia brick. On the one hand, it can enable the electric heating device to be directly used under a high voltage of more than 10 kV. On the other hand, the air accommodated between the air through holes and the electric heating wire can be used as an insulating medium to improve the insulation of the solid heat storage structure; and by increasing the distance b between the air through hole and the carbon brick and the shortest distance d between adjacent two air through holes, the risk of current being conducted by the carbon brick to the outside of the solid heat storage structure can be reduced, and further the insulation of the solid heat storage structure can be improved. At the same time, a heat storage unit composed of carbon bricks is coated on the outer layer of the magnesia brick, which can not only improve the heat storage performance of the solid heat storage structure, but also improve the heat exchange rate of the solid heat storage structure.

[0026] In one embodiment, the material of the electric heating wire described in the present disclosure is a conventional selection in the art, and no special requirements are made in this application. For example, the material of the electric heating wire is selected from those that can not only withstand the voltage use conditions below 10 kV, but also withstand the voltage above 10 kV and the heat at this voltage. Preferably, the material of the electric heating wire is an iron-chromium-aluminum alloy material.

[0027] In one embodiment, the shape of the electric heating wire used in the present disclosure is a cylinder, and the extending direction of the electric heating wire is the same as the extending direction of the air through hole; preferably, the electric heating wire is coaxially disposed with the air through hole. In this embodiment, by arranging the electric heating wire, the electric heating wire can be prevented from contacting the side wall of the air through hole, and the insulation of the solid heat storage structure can be further improved.

[0028] In one embodiment, the ratio of the aperture diameter of the air through-hole to the outer diameter of the electric heating wire is defined as (1.2 to 3.5):1, preferably (2.4 to 2.6):1. In this embodiment, when the distance between the electric heating wire and the inner wall of the air through-hole is small, there may be a risk of accidental contact and electric leakage; when the distance between the electric heating wire and the inner wall of the air through-hole is large, it will affect the effect and rate of heat transfer from the electric heating wire to the magnesia brick.

[0029] Among them, the preparation method of the magnesia brick used in the present disclosure is a conventional choice in the art, and no special requirements are made in this application. For example, the magnesia brick is formed by pressing a mixture of magnesia solid and binder evenly.

[0030] Among them, the shape of the magnesia brick is a column with a rectangular cross-section. In this embodiment, since the magnesia brick is coated with a carbon brick on the outside, in order to improve the rate and heat transfer effect of heat transfer from the magnesia brick to the heat storage unit, the magnesia brick is set as a column with a rectangular cross-section, so that when the heat storage unit contacts the magnesia brick, the contact area is as large as possible, thereby improving the heat transfer effect and the rate of heat transfer.

[0031] In a preferred embodiment, in order to further improve the heat transfer effect and transfer rate of the insulating layer, the specifications of the magnesia brick can be optimized. Specifically, the size of the magnesia brick used in the present disclosure is a length of 250 to 260 mm, a width of 140 to 160 mm, and a height c of 170 to 190 mm. As Figure 1 shown, in this application, the length along the extension direction of the electric heating wire is the length of the magnesia brick, and the height of the solid heat storage structure in the normal use state is the height of the magnesia brick; the length in the same cross-section and perpendicular to the height is the width of the magnesia brick.

[0032] Among them, in order to further improve the insulation performance of the magnesia brick, the ratio of the volume of the air through-hole to the volume of the magnesia brick is (0.10 to 0.16):1, preferably (0.12 to 0.14):1.

[0033] In one embodiment, the heat storage unit is composed of multiple carbon bricks wrapped outside the magnesia brick. There may be a certain distance between two adjacent carbon bricks or two adjacent carbon bricks may be in close contact. The area near the surface of the carbon brick and the magnesia brick may be in direct contact with the magnesia brick or there may be a certain distance. Preferably, two adjacent carbon bricks are tightly combined, and the carbon brick and the magnesia brick are tightly combined.

[0034] Among them, the shape of the carbon brick is a column with a rectangular cross-section.

[0035] Among them, the material of the carbon brick includes flake graphite and amorphous carbon; the weight ratio of the flake graphite to the amorphous carbon is (3-4):(1-2), preferably (3.2-3.6):(1.2-1.6). In this embodiment, making the carbon brick from flake graphite and amorphous carbon in a certain proportion can improve the thermal conductivity of the carbon brick, and then enable more heat on the magnesia brick to be transferred to the carbon brick faster and in greater quantity.

[0036] Among them, in order to further improve the heat storage performance and heat transfer effect, the specifications of the carbon brick are defined. In this application, in the normal use state of the solid heat storage structure, the length of the carbon brick along the height direction of the magnesia brick is used as the height of the carbon brick, the length along the width direction of the magnesia brick is used as the width of the carbon brick, and the length along the extension direction of the electric heating wire is used as the length of the carbon brick. Specifically, the size of the carbon brick used in this disclosure is: the length is 115-135 mm, the width is 140-160 mm, and the height is 70-80 mm.

[0037] In one embodiment, the insulating unit is formed by arranging a plurality of magnesia bricks at a certain distance on the same horizontal plane. Preferably, the distance between adjacent two magnesia bricks is the same, and the shortest distance a between adjacent two magnesia bricks is 70-120 mm.

[0038] In a preferred embodiment, the shortest distance a between adjacent two magnesia bricks is matched with the size of the carbon brick, that is, the distance a is 70-80. In this embodiment, the shortest distance a between adjacent two magnesia bricks is matched with the size of the carbon brick, which can make the two magnesia bricks and the carbon brick closely combined, and can further improve the heat storage performance and heat exchange rate of the solid heat storage structure.

[0039] In one embodiment, the method for preparing the carbon brick includes:

[0040] (1) Mix the asphalt material and the carbon-containing material evenly to obtain a composition for heat storage carbon material; in the composition, the asphalt material and the carbon-containing material are usually used in the form of their respective powders for preparing the heat storage carbon material, and usually the asphalt material can be crushed and screened before use. Among them, the carbon-containing material is selected from flake graphite and amorphous carbon, and the weight ratio of the flake graphite to the amorphous carbon is (3-4):(1-2); the particle size of the flake graphite and the amorphous carbon is preferably 100-200 mesh; the particle size of the asphalt material is preferably less than 300 mesh (i.e., the particle size is less than about 48 μm). The asphalt material is selected from coal-based asphalt and / or coal-based modified asphalt, and the C / H of the asphalt material is 1.3-1.7, the softening point ≥130 °C, and the residual carbon rate after carbonization ≥66%;

[0041] (2) Mold the composition of the heat storage carbon material to obtain a molded sample; specifically, place the composition into a mold, first evacuate the air, then apply pressure and increase the temperature to perform the molding. Generally, the conditions for the molding may include: the molding temperature is 150-600°C, and the pressure is 5-100 MPa. Preferably, the molding temperature is 200-500°C, and the pressure is 40-90 MPa. The molding time can be 0.5-3 hours.

[0042] (3) In an inert atmosphere, sinter the molded sample to obtain the heat storage carbon material; the sintering can be carried out in a carbonization furnace. The inert gas used is not particularly limited and can be a conventional choice in the art, such as nitrogen, argon, etc. The sintering temperature is not less than 800°C, and the sintering time at this temperature can be 0.5-10 hours. Preferably, the sintering temperature is 900-1400°C, and the sintering time is 1-4 hours.

[0043] In a preferred embodiment, the shortest distance b between the air through-hole and the edge of the magnesia brick is preferably 30-72 mm, more preferably 30-50 mm. In this embodiment, the shortest distance b between the air through-hole and the edge of the magnesia brick is the shortest distance between the air through-hole and the surface of the carbon brick; by setting an appropriate distance b, on the one hand, the efficiency and rate of heat transfer between the magnesia brick and the carbon brick can be further improved; on the other hand, the risk of current being conducted by the carbon brick to the outside of the solid heat storage structure can be further reduced, and thus the insulation of the solid heat storage structure can be further improved.

[0044] In one embodiment, the number of carbon bricks and magnesia bricks provided can be set according to the specifications of the device using the solid heat storage structure. For example, in a specific embodiment of the present disclosure, the number of magnesia bricks is more than 2, and the number of carbon bricks in the insulation unit is more than 22.

[0045] In a specific embodiment, as Figure 2 shown, the solid heat storage structure includes an intermediate composite layer 6, a first carbon brick layer 5, and a second carbon brick layer 7; the intermediate composite layer 6 includes a plurality of the magnesia bricks and a plurality of the carbon bricks; the plurality of carbon bricks are arranged at intervals along the radial direction of the solid heat storage structure, and a magnesia brick is provided between two adjacent carbon bricks; the first carbon brick layer 5 and the second carbon brick layer 7 are respectively formed by laying a plurality of carbon bricks along the radial direction of the solid heat storage structure; the first carbon brick layer 5 and the second carbon brick layer 7 are arranged on both sides of the intermediate composite layer 6.

[0046] In one embodiment, the solid heat storage structure is a column with a rectangular cross-section.

[0047] In one embodiment, the contact surfaces of the intermediate composite layer 6, the first carbon brick layer 5, and the second carbon brick layer 7 are flat.

[0048] In one embodiment, the side walls between the magnesia bricks in the intermediate composite layer 6 are tightly bonded to the carbon bricks in the intermediate composite layer 6.

[0049] In one embodiment, since the intermediate composite layer 6, the first carbon brick layer 5, and the second carbon brick layer 7 are tightly bonded under the normal use state of the solid heat storage structure, the shortest distance between the first carbon brick layer 5 and the second carbon brick layer 7 is the height c of the magnesia brick-carbon brick, where the height c of the magnesia brick-carbon brick is 90 - 160 mm, preferably 110 - 150 mm.

[0050] In this embodiment, since the outer layer of the magnesia brick is coated with a carbon brick, in order to improve the transfer rate and heat transfer effect when heat is transferred from the magnesia brick to the carbon brick, the carbon brick is set to be square so that when the carbon brick contacts the magnesia brick, the contact area is as large as possible, thereby improving the heat transfer effect and the heat transfer rate.

[0051] In one embodiment, in order to avoid the uneven heat transfer caused by the cold zone generated due to the relatively large distance between the electric heating wires, the shortest distance d between two adjacent air through holes is limited to 140 - 210 mm, preferably 160 - 200.

[0052] In one embodiment, in order to further reduce the weight and heat storage performance of the solid heat storage structure, the weight ratio of the carbon brick to the magnesia brick is limited to (1 - 3):(1 - 2), preferably (1.5 - 2.5):(1.1 - 1.6). In this embodiment, since the thermal conductivity of the carbon brick is better than that of the magnesia brick, if the weight of the carbon brick is greater than that of the magnesia brick, the heat transferred to the magnesia will be quickly absorbed by the carbon brick and then transferred to the heat-using equipment, and at this time, a large amount of heat cannot be stored inside the carbon brick, resulting in a lower maximum heat storage temperature; if the weight of the carbon brick is less than that of the magnesia brick, the heat inside the magnesia brick is difficult to be quickly absorbed by the carbon brick, and the temperature inside the magnesia brick will continue to rise. Although the heat storage performance is improved, the safety will be reduced. In order to balance the heat storage performance and safety, the weights of the carbon brick and the magnesia brick are limited.

[0053] In one embodiment, in order to further reduce the weight and heat storage performance of the solid heat storage structure, the volume ratio of the carbon brick to the magnesia brick is limited to (3 - 7):1, preferably (4 - 6):1.

[0054] In one embodiment, the heat storage temperature of the solid heat storage structure described in the present disclosure is above 900 °C, and the operating voltage of the solid heat storage structure is above 10 kV.

[0055] In one embodiment, in order to improve the structural strength of the solid heat storage structure, an adhesive may be provided on the contact surface between the magnesia brick and the carbon brick, and the normal operating temperature of the adhesive needs to be above 900 °C.

[0056] In another embodiment, in order to improve the structural strength of the solid heat storage structure, connectors may be provided in the solid heat storage structure so that all components therein can be tightly combined.

[0057] In one embodiment, the solid heat storage structure of the present disclosure is subjected to a high-voltage insulation test.

[0058] Among them, the method of the high-voltage insulation test includes: 1) heating the test body to 950 °C, cutting off the power and observing the temperature reduction rate, and controlling that the temperature of the test body is not lower than 900 °C within 5 minutes, which is regarded as meeting the test conditions; 2) connecting the heating element in the test body to the test transformer and gradually increasing the test voltage to 25 kV; 3) continuously testing for 10 minutes, and the leakage current of the instrument is not higher than 10 mA, which is judged as qualified insulation.

[0059] The present disclosure will be further described below through examples, but the present disclosure is not limited thereby.

[0060] Example 1

[0061] The structure of the solid heat storage structure is as Figure 1 and Figure 2 shown. The solid heat storage structure contains 2 electric heating wires, 2 magnesia bricks and 22 carbon bricks. Specifically, the solid heat storage structure includes an intermediate composite layer 6, a first carbon brick layer 5 and a second carbon brick layer 7; the intermediate composite layer 6 includes 2 magnesia bricks and 6 carbon bricks; among them, the 2 magnesia bricks are arranged at intervals, and the space between adjacent 2 magnesia bricks is filled with 2 carbon bricks, and the sides of the 2 magnesia bricks are respectively filled with 2 carbon bricks; the first carbon brick layer 5 and the second carbon brick layer 7 are each composed of 8 carbon bricks laid flat along the radial direction of the solid heat storage structure; the first carbon brick layer 5 and the second carbon brick layer 7 are arranged on both sides of the intermediate composite layer 6.

[0062] Among them, the weight ratio of flake graphite to amorphous carbon in the carbon brick is 3.4:1.4; the length of the carbon brick is 125 mm, the width is 150 mm, and the height is 80 mm; the length of the magnesia brick is 250 mm, the width is 180 mm, and the height is 150 mm; the shortest distance a between two adjacent magnesia bricks is 80 mm; the shortest distance b between the air through-hole and the edge of the magnesia brick is 33 mm; the height c of the magnesia brick is 150 mm; the shortest distance d between two adjacent air through-holes is 194 mm; the ratio of the aperture diameter of the air through-hole on the magnesia brick to the outer diameter of the electric heating wire is 2.5:1; the ratio of the volume of the air through-hole on the magnesia brick to the volume of the magnesia brick is 0.13:1.

[0063] Comparative Example 1

[0064] The preparation method of the carbon brick and the structure of the solid heat storage structure are the same as those in Example 1, except that the height c of the magnesia brick is 185 mm.

[0065] Comparative Example 2

[0066] The preparation method of the carbon brick and the structure of the solid heat storage structure are the same as those in Example 1, except that the shortest distance b between the air through-hole and the edge of the magnesia brick is 15 mm.

[0067] Comparative Example 3

[0068] The preparation method of the carbon brick and the structure of the solid heat storage structure are the same as those in Example 1, except that the shortest distance d between two adjacent air through-holes is 100 mm.

[0069] Test Example

[0070] The insulation and heat transfer coefficients of the solid heat storage structures in Example 1 and Comparative Examples 1 to 3 were measured. The specific test methods include: (1) Screening the solid heat storage structure: After raising the temperature of the solid heat storage structure to 950 °C, power off, and let the temperature of the solid heat storage structure naturally cool down at room temperature until the temperature drops to 900 °C, and obtain the time t used for cooling. If t is less than 5 minutes, it means that the solid heat storage structure is unqualified. If t is more than 5 minutes, the solid heat storage structure will be subjected to subsequent tests.

[0071] (2) Insulation performance and heat storage performance test: After connecting the solid heat storage structure to the leakage current detection device and connecting the electric heating wire to the test transformer; energize the electric heating wire until the voltage of the electric heating wire in the solid heat storage structure rises to 25 kV, and maintain this voltage for 10 minutes, and obtain the highest leakage current of the solid heat storage structure within the above 10 minutes and the heat transfer coefficient within 10 minutes. The obtained results are shown in Table 1.

[0072] Table 1 Test Results of Solid Heat Storage Structures in Examples and Comparative Examples

[0073] Name Unit Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 Test Temperature ℃ 900 900 900 900 Test Voltage kV 25 25 25 25 Leakage Current mA 8.4 (Qualified) 6.8 (Qualified) 23.2 (Unqualified) 23.2 (Unqualified) Heat Transfer Coefficient <![CDATA[W / (m 2 .℃)]]> 18.5 4.4 20.3 9.6

[0074] As shown in Table 1, by comparing the data in Example 1 and Comparative Examples 1 to 3, it can be seen that by using the method of the present disclosure, not only can the insulation of the solid heat storage structure be improved, but also the heat storage performance and heat exchange rate of the solid heat storage structure can be improved. By comparing the data in Example 1 and Comparative Example 1, it can be seen that when the height c of the magnesia brick is 90 - 160 mm, the heat storage performance of the solid heat storage structure can be improved. By comparing the data in Example 1 and Comparative Example 2, it can be seen that when the shortest distance b between the air through-holes and the edge of the magnesia brick is 30 - 72 mm, the insulation of the solid heat storage structure can be improved; by comparing the data in Example 1 and Comparative Example 3, it can be seen that when the shortest distance d between two adjacent air through-holes is 140 - 210 mm, not only can the insulation of the solid heat storage structure be improved, but also the heat storage performance and heat exchange rate of the solid heat storage structure can be improved.

[0075] The preferred embodiments of the present disclosure have been described in detail above in conjunction with the accompanying drawings. However, the present disclosure is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present disclosure, various simple modifications can be made to the technical solutions of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0076] In addition, it should be noted that, in the above specific embodiments, the various specific technical features described can be combined in any suitable manner without conflict. To avoid unnecessary repetition, the present disclosure will not separately describe various possible combination methods.

[0077] Furthermore, any combination can be made between various different embodiments of the present disclosure as long as it does not violate the idea of the present disclosure, and it should also be regarded as the content disclosed by the present disclosure.

Claims

1. A solid heat storage structure, characterized in that, The solid heat storage structure includes: a heating unit, the heating unit including an electric heating wire; an insulating unit, the insulating unit including magnesia bricks, the magnesia bricks including air through-holes for accommodating air; the electric heating wire is disposed in the air through-holes of the magnesia bricks; a heat storage unit, the heat storage unit being a carbon brick, the heat storage unit covering the outside of the insulating unit and separating adjacent two of the insulating units from each other; the shortest distance b between the air through-hole and the edge of the magnesia brick is 30 to 72 mm; the height c of the magnesia brick is 90 to 160 mm; the shortest distance d between adjacent two of the air through-holes is 140 to 210 mm.

2. The solid heat storage structure according to claim 1, characterized in that, The material of the carbon brick includes flake graphite and amorphous carbon; the weight ratio of the flake graphite to the amorphous carbon is (3 to 4):(1 to 2), preferably (3.2 to 3.6):(1.2 to 1.6).

3. The solid heat storage structure according to claim 1, characterized in that, The weight ratio of the carbon brick to the magnesia brick is (1 to 3):(1 to 2), preferably (1.5 to 2.5):(1.1 to 1.6).

4. The solid heat storage structure according to claim 1, characterized in that, The solid heat storage structure is a column with a rectangular cross-section; the magnesia brick and the carbon brick are respectively columns with a rectangular cross-section; the extending direction of the air through-hole of the magnesia brick is the same as the axial direction of the solid heat storage structure, preferably, the air through-hole is coaxially disposed with the magnesia brick.

5. The solid heat storage structure according to claim 4, characterized in that, The shortest distance b between the air through-hole and the edge of the magnesia brick is 30 to 50 mm.

6. The solid heat storage structure according to claim 4, characterized in that, The solid heat storage structure includes an intermediate composite layer (6), a first carbon brick layer (5) and a second carbon brick layer (7); the intermediate composite layer (6) includes a plurality of the magnesia bricks and a plurality of the carbon bricks; the plurality of the carbon bricks are spaced apart along the radial direction of the solid heat storage structure, and the magnesia bricks are disposed between adjacent two of the carbon bricks; the first carbon brick layer (5) and the second carbon brick layer (7) are respectively formed by laying a plurality of carbon bricks along the radial direction of the solid heat storage structure; the first carbon brick layer (5) and the second carbon brick layer (7) are disposed on both sides of the intermediate composite layer (6).

7. The solid heat storage structure according to claim 6, characterized in that, The shortest distance a between adjacent two of the magnesia bricks is 70 to 120 mm; the height of the magnesia brick is 110 to 150 mm; the shortest distance d between adjacent two of the air through-holes is 160 to 200 mm.

8. The solid heat storage structure according to claim 2, characterized in that, The shape of the electric heating wire is a cylinder; the extending direction of the air through-hole is the same as the extending direction of the electric heating wire; the ratio of the aperture of the air through-hole to the outer diameter of the electric heating wire is (1.2 to 3.5):

1.

9. The solid heat storage structure according to claim 1, characterized in that, the ratio of the volume of the air through-hole to the volume of the magnesia brick is (0.1 to 0.16):

1.

10. The solid heat storage structure according to claim 1, characterized in that, The heat storage temperature of the solid heat storage structure is above 900 °C; the material of the electric heating wire in the solid heat storage structure is an iron-chromium-aluminum alloy material, and the operating voltage of the electric heating wire is above 10 kV.

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