Solid heat storage device and optimization design method thereof

Abstract

The invention discloses a solid heat storage device and an optimization design method thereof, and belongs to the technical field of heat storage, the solid heat storage device comprises a heat storage body, a heating device and a heat removal medium, the heat storage body is provided with a heat storage channel and a heat removal channel which are not communicated with each other, and the heat storage channel and the heat removal channel are arranged in a crossed mode; the heating device is arranged in the heat storage channel; and the heat removal medium is filled in the heat removal channel. The heat storage channel and the heat taking channel which intersect with each other but do not communicate with each other are arranged on the heat storage body, the heating device is used for transferring heat to the heat storage body for storage, the heat taking medium is used for guiding out the heat of the heat storage body, and the heat storage efficiency and the heat taking efficiency can be improved.

Description

Technical Field

[0001] The present invention relates to the field of heat storage technology, and in particular to a solid heat storage device and an optimization design method thereof. Background Art

[0002] In the field of thermal energy storage and release technology, traditional solid heat storage devices have long dominated. Among them, MgO (magnesium oxide) bricks, as a classic heat storage material, are widely used due to their good chemical stability and certain heat capacity. Such devices usually rely on resistance wires as heat sources, converting electrical energy into thermal energy through heat conduction and thermal radiation and storing it in MgO bricks. When heat needs to be released, the convection heat transfer effect of hot air is used to transfer the heat energy stored in the MgO bricks to the external environment or a specific working medium.

[0003] However, although traditional solid heat storage devices have met the basic needs of thermal energy storage and conversion to a certain extent, their inherent technical limitations have become increasingly prominent and have become a bottleneck restricting the further development of this field. Specifically, there are the following problems: the thermal conductivity of traditional heat storage materials such as MgO bricks is relatively low, which means that during the heat storage process, the heat generated by the resistance wire is difficult to be quickly and evenly transferred to the entire heat storage body. Similarly, during the heat release process, the heat stored in the MgO bricks is also difficult to be efficiently released to the heat medium. This low thermal conductivity not only prolongs the time period of heat storage and heat release, reduces overall efficiency, but also increases energy consumption.

[0004] In view of the above problems, how to improve the structure to enhance the heat transfer efficiency of the solid heat storage device is a technical problem that needs to be solved. Summary of the invention

[0005] The purpose of the present invention is to provide a solid heat storage device and an optimized design method thereof to solve the problems existing in the above-mentioned prior art. By arranging heat storage channels and heat extraction channels that intersect but are not connected to each other on the heat storage body, using a heating device to transfer heat to the heat storage body for storage, and using a heat extraction medium to extract the heat of the heat storage body, the efficiency of heat storage and heat extraction can be improved.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] The present invention provides a solid heat storage device, comprising a heat storage body, a heating device and a heat extraction medium, wherein the heat storage body is provided with a heat storage channel and a heat extraction channel which are not connected to each other, and the heat storage channel and the heat extraction channel are arranged crosswise with each other; the heating device is arranged inside the heat storage channel; and the heat extraction medium is filled inside the heat extraction channel.

[0008] In one embodiment, the heat storage channel is located in the middle of the heat storage body, and the heat extraction channels are arranged in parallel and at intervals on both sides of the heat storage channel.

[0009] In one embodiment, the heat storage body is a rectangular parallelepiped structure, the heat extraction channel runs through a group of heat extraction surfaces in the rectangular parallelepiped structure, the heat storage channel runs through a group of heat storage surfaces in the rectangular parallelepiped structure, and the heat extraction channel is perpendicular to the heat storage channel.

[0010] In one embodiment, a top surface of the rectangular parallelepiped structure is provided with a positioning groove, and a bottom surface of the rectangular parallelepiped structure is provided with a positioning protrusion, and the positioning grooves and the positioning protrusions of different rectangular parallelepiped structures can be matched and connected.

[0011] In one embodiment, the positioning grooves and the positioning protrusions are both distributed in a cross shape.

[0012] In one embodiment, the distances between the heat extraction channels, between the heat extraction channels and the heat storage channels, and between the heat extraction channels and the wall surface of the heat storage body are equal.

[0013] In one embodiment, the heat extraction channel is arranged in the middle of the heat storage body, and the heat storage channel is arranged on both sides of the heat extraction channel.

[0014] In one embodiment, the heat extraction medium is carbon dioxide gas; and the heat storage body is cast iron.

[0015] The present invention also provides an optimization design method, which is applied to the solid heat storage device as described above, and includes the following contents:

[0016] It is known that the working temperature range of the heat storage body is T1~T2, the working temperature range of the heat medium is t1~t2, the diameter of the heat channel is d, the number of heat channels is n, and the heat storage body adopts a rectangular structure. Determine the length L of the heat channel, the width W of the heat section, and the height H of the heat section;

[0017] Determine the length of the heat extraction channel:

[0018]

[0019] Where S is the heat exchange area;

[0020] Determine the height of the heat extraction section:

[0021] H = D + 2 × (d + 2δ);

[0022] Determine the width of the heat extraction section:

[0023] W = (n / 2 + 1) δ + (n / 2) d;

[0024] Wherein, δ is the distance between the heat extraction channels, between the heat extraction channel and the heat storage channel, and between the heat extraction channel and the wall of the heat storage body.

[0025] In one embodiment, the design parameters are checked:

[0026] Actual volume:

[0027] V 实 =L×W×HV 取热 -V 储热 ;

[0028] In the above formula, V 取热 is the volume of the heat channel, V 储热 is the volume of the heat storage channel, calculated according to the following formulas:

[0029] V 取热 =nπ(d / 2) 2 L;

[0030] V 储热 =π(D / 2) 2 W;

[0031] Actual heat storage capacity:

[0032] P 实 =ρV 实 (C p1 T1-C p2 T2);

[0033] In the above formula, ρ is the density of the heat storage body, C p1 and C p2 are the specific heat capacities of the heat storage body at working temperatures T1 and T2 respectively;

[0034] Design margin calculation:

[0035] ε=(P 实 -P) / P.

[0036] Compared with the prior art, the present invention has achieved the following technical effects:

[0037] The present invention provides heat storage channels and heat extraction channels that intersect but are not interconnected on a heat storage body, uses a heating device to transfer heat to the heat storage body for storage, and uses a heat extraction medium to extract the heat of the heat storage body. The heat storage channel and the heat extraction channel do not interfere with each other. The heat storage channel can facilitate heat storage in the heat storage body, and the heat extraction channel can facilitate heat extraction from the heat storage body, thereby improving the efficiency of heat storage and heat extraction.

[0038] Other technical solutions included in the present invention can also achieve the following technical effects:

[0039] MgO bricks and other materials have poor thermal stability. When working in high temperature environment for a long time, they are prone to changes in physical or chemical properties, such as thermal expansion, cracking or chemical decomposition. This not only shortens the service life of the heat storage material, but also may cause safety hazards, such as material shedding, equipment leakage, etc., which seriously restricts the application scope and reliability of solid heat storage devices. The present invention adopts cast iron with high thermal conductivity as the main material of the heat storage body, which can ensure the thermal stability of the material and the safety of the device. Carbon dioxide gas is used as the heat medium. Carbon dioxide gas has the advantages of low cost, stable chemical properties, high thermal stability and large enthalpy difference. The combination of cast iron and carbon dioxide gas can achieve small temperature difference heat transfer between the heat storage body and the heat medium, and the heat storage and release rate is fast and the efficiency is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0041] Figure 1 This is a schematic diagram of the structure of a solid heat storage device in an embodiment of the present invention;

[0042] Figure 2 for Figure 1 Schematic diagram from another angle;

[0043] Figure 3 A schematic diagram of a heat section in an embodiment of the present invention;

[0044] Among them, 1. heat storage body; 2. heat storage channel; 3. heat extraction channel; 4. positioning groove; 5. positioning protrusion. DETAILED DESCRIPTION

[0045] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0046] The purpose of the present invention is to provide a solid heat storage device and an optimized design method thereof to solve the problems existing in the prior art. By arranging heat storage channels and heat extraction channels that intersect but are not interconnected on a heat storage body, a heating device is used to transfer heat to the heat storage body for storage, and a heat extraction medium is used to extract the heat of the heat storage body, thereby improving the efficiency of heat storage and heat extraction.

[0047] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0048] like Figure 1 to Figure 3 As shown, the present invention provides a solid heat storage device, including a heat storage body 1, a heating device and a heat medium, wherein the heat storage body 1 is generally a block structure, at least one block is provided, and multiple blocks can also be combined to form a solid heat storage device. The heat storage body 1 can adopt a structure in the form of a cuboid, a sphere, a pyramid, etc., or other irregular shapes. At the same time, the heat storage material of the heat storage body 1 has the advantages of high temperature resistance, corrosion resistance, and oxidation resistance. The device can be suitable for long-term start and stop, frequent heat storage and release, and has a long service life while ensuring safe and stable operation. The heat storage body 1 is provided with a heat storage channel 2 and a heat extraction channel 3 that are not connected to each other. The heat storage channel 2 and the heat extraction channel 3 can be pipes passing through the heat storage body 1, or can be obtained by directly opening holes on the heat storage body 1. The cross-sections of the heat storage channel 2 and the heat extraction channel 3 can be set in different shapes such as circular, rectangular or triangular, preferably circular, which can make the heat storage channel 2 or the heat extraction channel 3 more uniformly exchange heat with the heat storage body 1. Generally, the number of heat extraction channels 3 is greater than the number of heat storage channels 2, which is convenient for efficient heat extraction. The heat storage channels 2 and the heat extraction channels 3 are arranged crosswise with each other, and can be at right angles or acute angles, and are not parallel to each other. This method can utilize the heat storage channels 2 to effectively store heat in the heat storage body 1, and when the heat extraction channels 3 extract heat, the heat from various parts of the heat storage body 1 can be extracted, further improving the efficiency of heat storage and heat extraction. The heating device is arranged inside the heat storage channel 2, and is used to transfer heat to the heat storage body 1 in the heat storage channel 2. The heat extraction medium is filled inside the heat extraction channel 3, and is used to exchange heat with the heat storage body 1 in the heat extraction channel 3 to extract the heat in the heat storage body 1. The heat extraction medium can be a gas or a liquid.

[0049] The present invention provides a heat storage channel 2 and a heat extraction channel 3 that cross but are not interconnected on the heat storage body 1, uses a heating device to transfer heat to the heat storage body 1 for storage, and uses a heat extraction medium to extract the heat of the heat storage body 1. The heat storage channel 2 and the heat extraction channel 3 do not interfere with each other. The heat storage channel 2 can facilitate heat storage in the heat storage body 1, and the heat extraction channel 3 can facilitate heat extraction from the heat storage body 1, thereby improving the efficiency of heat storage and heat extraction. The solid heat storage device of the present invention can be used in the fields of heating, industrial steam, and peak and frequency regulation of power plants.

[0050] In one embodiment, the heat storage channel 2 is located in the middle of the heat storage body 1. When the heating device is used for heating, the heat can be better stored in various parts of the heat storage body 1, so as to avoid uneven temperature conditions that lead to a reduction in the heat storage capacity of the heat storage body 1. The heat extraction channels 3 are arranged in parallel and spaced on both sides of the heat storage channel 2, so as to better utilize the heat extraction channels 3 to extract the heat stored around the heat storage channel 2.

[0051] In one embodiment, the heat storage body 1 is a rectangular parallelepiped structure, and the rectangular parallelepiped structure has six faces, one group of which is used as a heat extraction face, another group of which is used as a heat storage face, and another group of which is used as a top face or a bottom face. The heat extraction channel 3 runs through a group of heat extraction faces in the rectangular parallelepiped structure, and the heat storage channel 2 runs through a group of heat storage faces in the rectangular parallelepiped structure. The heat extraction face and the heat storage face are perpendicular to each other. When a heat extraction pipeline is installed on the heat extraction channel 3 or a heat storage line is installed on the heat storage channel 2, interference between the heat extraction pipeline and the heat storage line can be effectively avoided, thereby improving the convenience of application of the solid heat storage device. The heat extraction channel 3 is arranged perpendicular to the heat storage channel 2. On the basis that the heat storage body 1 is a rectangular parallelepiped structure, the heat storage channel 2 and the heat extraction channel 3 can be extended along the direction of the edges of the rectangular parallelepiped structure, and more heat extraction channels 3 can be arranged to further improve the heat storage and heat extraction efficiency.

[0052] In one embodiment, the top surface of the rectangular parallelepiped structure is provided with a positioning groove 4, and the bottom surface of the rectangular parallelepiped structure is provided with a positioning protrusion 5. It should be noted that the top surface and the bottom surface mentioned here are only from Figure 1 That is, the top surface can also be placed at the bottom, and the bottom surface can also be placed at the top (such as Figure 2 As shown in the figure, the top and bottom surfaces should not be used as a limitation on the specific installation position and method of the rectangular parallelepiped structure. The positioning grooves 4 and the positioning protrusions 5 of different rectangular parallelepiped structures can be connected in coordination, that is, the heat storage body 1 can be arranged in multiple pieces, and the positioning grooves 4 and the positioning protrusions 5 can be used to achieve positioning, thereby improving the convenience of installation and the accuracy of the installation position.

[0053] In one embodiment, the positioning groove 4 and the positioning protrusion 5 are both distributed in a cross shape, which can position the heat storage body 1 in both the horizontal and vertical directions, ensuring that after positioning and connection, the heat extraction surface of the heat storage body 1 is flush with the heat extraction surface, and the heat storage surface is flush with the heat storage surface. In addition, the cross-sections of the positioning groove 4 and the positioning protrusion 5 can be set to be triangular, and the triangular positioning protrusion 5 cooperates with the triangular positioning groove 4, so that the positioning protrusion 5 can enter the positioning groove 4.

[0054] In one embodiment, the distances between the heat extraction channels 3, between the heat extraction channels 3 and the heat storage channels 2, and between the heat extraction channels 3 and the wall of the heat storage body 1 are equal, which is convenient for heat transfer and also convenient for design.

[0055] In one embodiment, the heat extraction channel 3 is arranged in the middle of the heat storage body 1, and the heat storage channels 2 are arranged on both sides of the heat extraction channel 3. When storing heat, heat is transferred toward the middle of the heat storage body 1 through the heat storage channel 2. When extracting heat, the heat in the middle of the heat storage body 1 is extracted through the heat extraction channel 3. This method can also maintain the smooth progress of heat storage and heat extraction. However, compared with the method in which the heat storage channel 2 is arranged in the middle, more heat storage channels 2 need to be arranged, which may occupy the actual heat storage volume of the heat storage body 1 and reduce the overall heat storage amount.

[0056] In one embodiment, the heat medium is carbon dioxide gas, and the heat storage body 1 is cast iron. The heat storage body 1 made of cast iron material has excellent heat storage performance and heat transfer performance, with a thermal conductivity of more than 40W / (m·K) and a specific heat capacity of more than 0.5kJ / (kg·K). By using cast iron with high thermal conductivity as the main material of the heat storage body 1, the thermal stability of the material and the safety of the device can be ensured. The heat medium is carbon dioxide gas, and the heat of the heat storage body 1 is taken away by the flow of carbon dioxide gas in the heat collection channel 3. Carbon dioxide gas has the advantages of low cost, stable chemical properties, high thermal stability, and large enthalpy difference. The combination of cast iron and carbon dioxide gas can achieve small temperature difference heat transfer between the heat storage body 1 and the heat medium, and the heat storage and release rate is fast and the efficiency is high.

[0057] In one embodiment, the heating device in the heat storage channel 2 is an electromagnetic heater, which utilizes electromagnetic eddy current action and radiation heat transfer to heat the heat storage body 1, so that the temperature of the heat storage body 1 reaches above 700°C.

[0058] The present invention also provides an optimization design method, which is applied to the solid heat storage device as described above, and includes the following contents:

[0059] It is known that the working temperature range of the heat storage body 1 is T1-T2, the working temperature range of the heat medium is t1-t2, the diameter of the heat channel 3 is d, the number of heat channels 3 is n, and the heat storage body 1 adopts a rectangular parallelepiped structure. Determine the length L of the heat channel 3, the width W of the heat section, and the height H of the heat section;

[0060] Determine the length of heat extraction channel 3:

[0061]

[0062] Where S is the heat exchange area;

[0063] Determine the height of the heat extraction section:

[0064] H = D + 2 × (d + 2δ);

[0065] Determine the width of the heat extraction section:

[0066] W = (n / 2 + 1) δ + (n / 2) d;

[0067] Among them, δ is the distance between the heat extraction channels 3 , between the heat extraction channel 3 and the heat storage channel 2 , and between the heat extraction channel 3 and the wall of the heat storage body 1 .

[0068] In one embodiment, the design parameters are checked:

[0069] Actual volume:

[0070] V 实 =L×W×HV 取热 -V 储热 ;

[0071] In the above formula, V 取热 is the volume of heat channel 3, V 储热 is the volume of the heat storage channel 2, which is calculated according to the following formulas:

[0072] V 取热 =nπ(d / 2) 2 L;

[0073] V 储热 =π(D / 2) 2 W;

[0074] Actual heat storage capacity:

[0075] P 实 =ρV 实 (C p1 T1-C p2 T2);

[0076] In the above formula, ρ is the density of the heat storage body 1, C p1 and C p2 are the specific heat capacities of the heat storage body 1 at the working temperatures T1 and T2 respectively;

[0077] Design margin calculation:

[0078] ε=(P 实 -P) / P.

[0079] The present invention provides a specific embodiment of the heat storage material used in the solid heat storage device as follows:

[0080] The chemical composition, mechanical properties and physical parameters of the heat storage materials are shown in Tables 1 to 3:

[0081] Table 1 Mechanical properties of cast iron

[0082]

[0083] Table 2 Chemical composition of cast iron

[0084] chemical composition C Mn Si S≤ P≤ Cr≤ Mo≤ <![CDATA[SCSiMn2H]]> 0.4-0.47 0.7-1.4 0.3-0.8 0.035 0.035 0.03 0.03

[0085] Table 3 Physical properties of cast iron

[0086] <![CDATA[Density g / cm 3 > Thermal expansion coefficient / ℃ Thermal conductivity W / (m·K) Specific heat capacity kJ / (kg·K) 6.9～7.3 <![CDATA[1.1×10 -5 ~1.8×10 -5 ]]> 40～60 0.528～0.687

[0087] The present invention provides an embodiment of determining the heat extraction gas used in the solid heat storage device as follows:

[0088] The physical properties of common gases are shown in Table 4. It can be seen from the table that, excluding combustible gases, oxidizing gases, rare gases and relatively expensive gases, only water vapor, carbon dioxide and nitrogen can be used as heat extraction media. Among them, carbon dioxide has the largest enthalpy difference per unit volume and has the largest heat carrying capacity under the same conditions. By analyzing and comparing common gases, carbon dioxide has the advantages of low cost, stable chemical properties, high thermal stability, and large enthalpy difference. Finally, carbon dioxide gas was selected as the heat extraction gas for the solid heat storage device.

[0089] Table 4 Gas List

[0090]

[0091] The present invention also provides an implementation method of optimizing the structural design of the heat storage body 1 as follows:

[0092] Component mathematical model:

[0093] In this embodiment, the heat storage body 1 adopts a rectangular structure, the length of the heat extraction channel 3 is L, the width of the heat extraction section is W, the height of the heat extraction section is H, the working temperature range of the heat storage body 1 is T1~T2 (T1>T2), the working temperature range of the heat extraction medium is t1~t2 (t1>t2), the diameter of the heat extraction channel 3 is d, and the number of heat extraction channels 3 is n.

[0094] ① Determination of the length of heat extraction channel 3

[0095] Heat medium mass flow rate q m

[0096]

[0097] Where P is the designed heat storage capacity of the heat storage body 1, in kW; h high and h low are the enthalpy values ​​corresponding to the working temperatures of the heat medium at t1 and t2, respectively, in kJ / kg;

[0098] Volume flow rate q v

[0099]

[0100] In the formula, q v is the volume flow rate of the heat medium, in m 3 / h;ρhigh and ρ low They are the densities of the heat medium at working temperatures t1 and t2, in kg / m 3 ;

[0101] Take the heat medium flow rate V

[0102]

[0103] Wherein, V is the flow rate of the heat medium, in m / s; d is the diameter of the heat channel 3; and n is the number of the heat channels 3.

[0104] Reynolds number

[0105]

[0106] Where ν is the dynamic viscosity coefficient of the fluid.

[0107] Prandtl number Pr

[0108]

[0109] Where Pr is the average Prandtl number of the heat medium; Pr high and Pr low are the Prandtl numbers corresponding to the working temperatures of the heat medium at t1 and t2 respectively.

[0110] Nusselt number

[0111] Nu=0.021Re 0.8 Pr 0.43 (6)

[0112] Thermal conductivity λ

[0113]

[0114] Where, λ is the average thermal conductivity of the heat medium; high and λ low are the thermal conductivities corresponding to the working temperatures of the heat medium at t1 and t2 respectively.

[0115] Convective heat transfer coefficient h

[0116]

[0117] Logarithmic mean temperature difference Δt

[0118]

[0119] Heat exchange area S

[0120]

[0121] The length L of the heat extraction channel 3

[0122]

[0123] Wherein, L is the length L of the heat extraction channel 3.

[0124] ② Determination of heat extraction cross-section size of heat storage device

[0125] The heat collection cross-sectional structure of the heat storage body 1 is as follows: Figure 2 As shown, assuming that the number of heat extraction channels 3 is n, the diameter is d, the distance between the heat extraction channels 3, the distance between the heat extraction channels 3 and the edge of the heat storage body 1, and the distance between the heat extraction channels 3 and the heat storage channel 2 is δ (δ ≥ 5 mm), and the diameter of the heat storage channel 2 is D, the heat extraction section height H and width W can be expressed as follows:

[0126] H=D+2×(d+2δ)(12)

[0127] W=(n / 2+1)δ+(n / 2)d(13)

[0128] ③Design parameter verification

[0129] After the initial design of the shape of the heat storage body 1 and the structural dimensions of the heat storage channel 2 and the heat extraction channel 3, the actual heat storage capacity of the heat storage body 1 needs to be checked:

[0130] Actual volume:

[0131] V 实 =L×W×HV 取热 -V 储热 (14)

[0132] In the above formula, V 取热 is the volume of heat channel 3, V 储热 is the volume of the heat storage channel 2, which is calculated according to the following formulas:

[0133] V 取热 =nπ(d / 2) 2 L(15)

[0134] V 储热 =π(D / 2) 2 W(16)

[0135] Actual heat storage capacity:

[0136] P 实 =ρV 实 (C p1 T1-C p2 T2)(17)

[0137] In the above formula, ρ is the density of the heat storage body 1, C p1 and C p2are the specific heat capacities of the heat storage body 1 at the working temperatures T1 and T2 respectively.

[0138] Design margin calculation:

[0139] ε=(P 实 -P) / P(18)

[0140] In the above formula, ε is the design margin.

[0141] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A solid heat storage device, characterized in that: include: A heat storage body, wherein the heat storage body is provided with a heat storage channel and a heat extraction channel which are not connected to each other, and the heat storage channel and the heat extraction channel are arranged crosswise with each other; A heating device, wherein the heating device is arranged inside the heat storage channel; and a heat extraction medium, wherein the heat extraction medium is filled in the heat extraction channel.

2. The solid heat storage device according to claim 1, characterized in that: The heat storage channel is located in the middle of the heat storage body, and the heat extraction channels are arranged in parallel and at intervals on both sides of the heat storage channel.

3. The solid heat storage device according to claim 2, characterized in that: The heat storage body is a rectangular parallelepiped structure, the heat extraction channel runs through a group of heat extraction surfaces in the rectangular parallelepiped structure, the heat storage channel runs through a group of heat storage surfaces in the rectangular parallelepiped structure, and the heat extraction channel is perpendicular to the heat storage channel.

4. The solid heat storage device according to claim 3, characterized in that: The top surface of the rectangular parallelepiped structure is provided with a positioning groove, and the bottom surface of the rectangular parallelepiped structure is provided with a positioning protrusion, and the positioning grooves and the positioning protrusions of different rectangular parallelepiped structures can be matched and connected.

5. The solid heat storage device according to claim 4, characterized in that: The positioning grooves and the positioning protrusions are both distributed in a cross shape.

6. The solid heat storage device according to claim 3, characterized in that: The distances between the heat extraction channels, between the heat extraction channels and the heat storage channels, and between the heat extraction channels and the wall surface of the heat storage body are equal.

7. The solid heat storage device according to claim 3, characterized in that: The heat extraction channel is arranged in the middle of the heat storage body, and the heat storage channel is arranged on both sides of the heat extraction channel.

8. The solid heat storage device according to claim 3, characterized in that: The heat extraction medium is carbon dioxide gas; the heat storage body is cast iron.

9. An optimization design method, characterized in that: The solid heat storage device as claimed in any one of claims 3 to 8 comprises the following contents: It is known that the working temperature range of the heat storage body is T1~T2, the working temperature range of the heat medium is t1~t2, the diameter of the heat channel is d, the number of heat channels is n, and the heat storage body adopts a rectangular structure. Determine the length L of the heat channel, the width W of the heat section, and the height H of the heat section; Determine the length of the heat extraction channel: Where S is the heat exchange area; Determine the height of the heat extraction section: H = D + 2 × (d + 2δ); Determine the width of the heat extraction section: W = (n / 2 + 1) δ + (n / 2) d; Wherein, δ is the distance between the heat extraction channels, between the heat extraction channel and the heat storage channel, and between the heat extraction channel and the wall of the heat storage body.

10. The optimization design method according to claim 9, characterized in that: Check the design parameters: Actual volume: V 实 =L×W×HV 取热 -V 储热 ; In the above formula, V 取热 is the volume of the heat channel, V 储热 is the volume of the heat storage channel, calculated according to the following formulas: V 取热 =nπ(d / 2) 2 L; V 储热 Dπ(D / 2) 2 W6 Actual heat storage capacity: P 实 =ρV 实 (C p1 T1-C p2 T2); In the above formula, ρ is the density of the heat storage body, C p1 and C p2 are the specific heat capacities of the heat storage body at working temperatures T1 and T2 respectively; Design margin calculation: ε=(P 实 -P) / P.

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