An electrically heated concrete accumulator

Abstract

This utility model discloses an electrically heated concrete accumulator, comprising a concrete accumulator body and a heat exchange tube assembly. The heat exchange tube assembly consists of multiple heat exchange tubes, each having a heat exchange channel for the flow of the heat exchange medium. Part or all of the tube body is embedded within the concrete accumulator body. The concrete accumulator body also contains several electrically heated channels, each housing an electrically heated element. The gap between the electrically heated element and the electrically heated channel is filled with a thermally conductive material. This utility model's concrete accumulator module achieves heat storage through electrically heated methods. The gap between the electrically heated element and the electrically heated channel is filled with a thermally conductive material, preventing direct contact between the electrically heated element and the concrete accumulator body. The thermally conductive material buffers the thermal expansion effect of the electrically heated element, blocks the conduction of mechanical stress to the concrete body, promotes uniform heat diffusion, suppresses thermal shock within the concrete, and improves the crack resistance of the concrete accumulator module.

Description

Technical Field

[0001] This utility model relates to the field of concrete heat storage technology, specifically to an electrically heated concrete heat storage device. Background Technology

[0002] In recent years, with the improvement of people's living standards and the adjustment of industrial structure, the peak-valley difference of my country's power grid has been increasing year by year, and the task of peak regulation of the power grid has become increasingly prominent. Storing the large amount of surplus electricity during the off-peak period as heat energy and using it for heating can balance changes in electricity load, improve the efficiency and security of the power grid, and reduce environmental pollution. It is an effective way to coordinate social and economic benefits.

[0003] Based on different heat storage mechanisms, heat storage can be divided into three types: sensible heat storage, phase change heat storage, and chemical reaction heat storage. Sensible heat storage mainly stores thermal energy by raising or lowering the temperature of the heat storage material. This is the simplest in principle, the most mature in technology, the most abundant in material sources, the lowest in cost, and commercially viable among the three heat storage methods.

[0004] Solid concrete heat storage has promising application prospects. Related technologies utilize heat accumulators that embed heat pipes inside the concrete, temporarily storing heat within it and releasing it during periods of insufficient heat. An example is the heat accumulator described in Reference 1.

[0005] Reference 1: Chinese patent document with publication number CN218410837U.

[0006] Reference 1 describes a solid concrete heat storage device, including a concrete heat storage structure, a base insulation layer, surrounding insulation layers, and heat exchange coils. The concrete heat storage structure is mounted on the base insulation layer, and the surrounding insulation layers are located on the top and sides of the concrete heat storage structure. The heat exchange coils are located inside the concrete heat storage structure. The first interface of the heat exchange coils is connected to a water supply device and a heating device, respectively, and the second interface of the heat exchange coils is connected to a superheated steam source and a superheated steam user, respectively. The superheated steam outlet of the heating device is connected to the second interface of the heat exchange coils. The heat exchange coils are arranged in a layered, meandering pattern within the concrete heat storage structure. Compared to molten salt heat storage, this heat storage device uses concrete for heat storage, which does not cause corrosion to the heat exchange pipelines, greatly improving safety and stability.

[0007] This heat storage device uses superheated steam to store heat in the concrete heat storage structure. Based on this, existing technologies also include auxiliary heat storage using electric heating, such as the heat storage device described in Reference 2.

[0008] Reference 2: Chinese patent document with publication number CN 217560433 U.

[0009] Reference 2 describes a concrete thermal storage system for industrial steam supply, comprising a concrete thermal storage body, electric heating components, a steam heating and supply pipe, a water supply pipeline, an external industrial steam pipeline, and a high-temperature steam source. The steam heating and supply pipe is installed inside the concrete thermal storage body, meandering upwards from the bottom. The electric heating components are interspersed between adjacent steam heating and supply pipes. The water supply pipeline and the high-temperature steam source are connected to the bottom inlet of the steam heating and supply pipe, and the top outlet of the steam heating and supply pipe is connected to the external industrial steam pipeline. This concrete thermal storage system stores steam heat energy in the concrete thermal storage body and, combined with electric heating for heat storage, achieves dynamic heat storage. Furthermore, the concrete thermal storage device has advantages such as low heat storage cost, stable physical properties, and easy on-site installation and pouring. Utility Model Content

[0010] The purpose of this invention is to enrich the technical routes of concrete heat storage technology and provide an electrically heated concrete heat storage device that is different from the existing technology.

[0011] To address the shortcomings of the aforementioned technical problems, the present invention adopts the following technical solution: an electrically heated concrete accumulator, comprising a concrete accumulator body and a heat exchange tube assembly, wherein the heat exchange tube assembly consists of multiple heat exchange tubes, each heat exchange tube having a heat exchange channel for the flow of the heat exchange medium, and part or all of the tube body of the heat exchange tube is inserted into the concrete accumulator body.

[0012] The concrete heat storage body is also provided with several electric heating channels, and electric heating elements are installed in the electric heating channels. The gap between the electric heating elements and the electric heating channels is filled with heat-conducting material.

[0013] As a further optimization of the electric heating concrete accumulator of this utility model: the electric heating channel is vertically arranged in the concrete accumulator body, and several electric heating channels are distributed on both sides of the heat exchange tube.

[0014] As a further optimization of the electric heating concrete accumulator of this utility model: the concrete accumulator body includes multiple concrete accumulator blocks arranged side by side, and there is a gap between two adjacent concrete accumulator blocks that can absorb the expansion and deformation of the concrete.

[0015] As a further optimization of the electrically heated concrete accumulator of this utility model: the heat-conducting material is magnesium oxide powder.

[0016] As a further optimization of the electric heating concrete accumulator of this utility model: the heat exchange tube is a serpentine tube with a straight tube section and an arc tube section connecting the upper and lower straight tube sections. The multiple heat exchange tubes of the heat exchange tube group are parallel to each other. The heat exchange tube group also includes an inlet main pipe and an outlet main pipe. The inlet ends of the multiple heat exchange tubes are all connected to the inlet main pipe, and the outlet ends of the multiple heat exchange tubes are all connected to the outlet main pipe.

[0017] As a further optimization of the electric heating concrete accumulator of this utility model: the outer wall of the straight section of the heat exchange tube is provided with longitudinal fins.

[0018] As a further optimization of the electrically heated concrete accumulator of this utility model: the outer wall of the heat exchange tube is provided with a release agent layer.

[0019] As a further optimization of the electric heating concrete accumulator of this utility model: the electric heating element is an electric heating rod.

[0020] As a further optimization of the electric heating concrete accumulator of this utility model: the electric heating element is a three-dimensional honeycomb mesh structure woven from electric heating wires.

[0021] As a further optimization of the electrically heated concrete heat storage device of this utility model, several temperature sensors are embedded in the concrete heat storage body.

[0022] This utility model has the following beneficial effects:

[0023] I. The concrete heat storage module of this utility model completes heat storage by electric heating. The electric heating element is set in the heating channel, and the gap between the electric heating element and the electric heating channel is filled with thermally conductive material. The electric heating element does not directly contact the concrete heat storage body. The thermally conductive material can buffer the thermal expansion effect of the electric heating element, block the mechanical stress from being conducted to the concrete body, and promote the uniform diffusion of heat, suppress the thermal shock inside the concrete, and improve the crack resistance of the concrete heat storage module.

[0024] II. This utility model designs the concrete heat storage body as a side-by-side independent block structure, and uses the expansion gap reserved between the blocks to absorb thermal expansion and contraction deformation, which can further improve the crack resistance and life of the concrete heat storage module (eliminating the risk of cracking in large-volume concrete). Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of the electrically heated concrete accumulator of this utility model;

[0026] Figure 2 This is a schematic diagram of the heat exchange tube assembly in the electrically heated concrete accumulator of this utility model.

[0027] Figure 3This is a schematic diagram of the arrangement of heat exchange tubes in the electrically heated concrete accumulator of this utility model (aligned).

[0028] Figure 4 This is a schematic diagram of the arrangement of heat exchange tubes in the electrically heated concrete accumulator of this utility model (staggered arrangement).

[0029] Figure 5 This is a schematic diagram of the structure of the electric heating concrete accumulator of this utility model (the concrete accumulator body is a split type);

[0030] Marked in the image:

[0031] 1. Concrete heat storage body;

[0032] 2. Heat exchanger tubes;

[0033] 201. Straight pipe section;

[0034] 202. Arc pipe section;

[0035] 3. Emergency exits;

[0036] 4. Import main pipe;

[0037] 5. Export Manager. Detailed Implementation

[0038] To better understand this utility model, the following embodiments further illustrate the content of this utility model, but the content of this utility model is not limited to the following embodiments.

[0039] like Figure 1 As shown: An electrically heated concrete accumulator includes a concrete accumulator body 1 and a heat exchange tube assembly. The heat exchange tube assembly consists of multiple heat exchange tubes 2. Each heat exchange tube 2 has a heat exchange channel for the flow of heat exchange medium, and part or all of the tube body of the heat exchange tube 2 is inserted into the concrete accumulator body 1.

[0040] The concrete heat storage body 1 is also equipped with several electric heating channels 3. The electric heating channels 3 are vertically arranged inside the concrete heat storage body 1, and the several electric heating channels 3 are distributed on both sides of the heat exchange tube 2.

[0041] An electric heating element is installed inside the electric heating channel 3, and the gap between the electric heating element and the electric heating channel 3 is filled with a thermally conductive material. The electric heating element does not directly contact the concrete heat storage body. The thermally conductive material can buffer the thermal expansion effect of the electric heating element, block the conduction of mechanical stress to the concrete body, and promote the uniform diffusion of heat, suppress the thermal shock inside the concrete, and improve the crack resistance of the concrete heat storage module.

[0042] The electric heating element can be a three-dimensional honeycomb structure woven from electric heating rods or electric heating wires. Multiple electric heating elements are controlled in a centralized power distribution architecture. All electric heating elements are connected to a unified three-phase power frequency bus, and the central controller dynamically allocates power according to a preset heat storage and release strategy.

[0043] Magnesium oxide powder can be selected as the thermally conductive material. Magnesium oxide powder is a high-performance thermally conductive and insulating material, possessing both high thermal conductivity (45-60 W / m·K at room temperature) and electrical insulation properties, enabling the construction of efficient heat transfer channels within concrete thermal storage modules. By filling the gaps between heating elements, magnesium oxide powder not only achieves rapid and uniform heat diffusion, but its near-metallic coefficient of thermal expansion effectively buffers thermal stress. Simultaneously, it completely isolates the current from contact with the concrete, avoiding the risk of electrochemical corrosion.

[0044] like Figure 2 As shown, the heat exchange tube 2 has a serpentine, zigzag-shaped tube body forming a continuous flow channel. It has a straight tube section 201 and an arc tube section 202 connecting the upper and lower straight tube sections 201. The heat exchange tube 2 can be made of high-temperature resistant stainless steel to resist alkaline corrosion and sulfur corrosion of concrete. The multiple heat exchange tubes 2 in the heat exchange tube group are parallel to each other. The heat exchange tube group also includes an inlet manifold 4 and an outlet manifold 5. The inlet ends of the multiple heat exchange tubes 2 are all connected to the inlet manifold 4, and the outlet ends of the multiple heat exchange tubes 2 are all connected to the outlet manifold 5. The outer wall of the straight tube section 201 of the heat exchange tube 2 is provided with longitudinal fins to enhance the concrete-tube wall contact area.

[0045] In the horizontal direction, the heat exchange tubes 2 arranged side by side are kept in the same horizontal position (e.g. Figure 3 As shown), of course, it can also be set in an alternating vertical form (such as...). Figure 4 As shown in the figure, this arrangement is conducive to the uniform heating of the concrete heat storage body 1.

[0046] The outer wall of heat exchange tube 2 is provided with a release agent layer. This release agent layer forms a continuous weak interface bonding zone during the concrete pouring and molding process, achieving a dual function: pre-isolation and anti-adhesion: during the concrete hardening stage, it isolates the tube wall from direct contact with the concrete, avoiding the thermal expansion coupling effect caused by adhesion. Stress decoupling protection: when the system is thermally cyclical, it allows the metal tube body and concrete to freely deform differentially along the axial direction, blocking the transmission of shear stress and preventing peeling and cracking of the tube-concrete interface.

[0047] To address the problem of concrete expanding and deforming upon heating, leading to cracking of the concrete heat storage body 1, this invention incorporates the following design: the concrete heat storage body 1 includes multiple concrete heat storage blocks arranged side-by-side (e.g., ...). Figure 5The concrete heat storage blocks have gaps between adjacent blocks to absorb the expansion and deformation of the concrete. It should be noted that multiple concrete heat storage blocks are arranged along the length of the straight pipe section 201 of the heat exchange pipe 2. By designing the concrete heat storage body as a parallel, independently segmented structure, the expansion gaps between the blocks absorb thermal expansion and contraction. This significantly improves the system's crack resistance and lifespan (eliminating the risk of cracking in large-volume concrete).

[0048] Several temperature sensors (armored sensors) are also embedded inside the concrete heat storage unit 1. As a hub for the conversion of energy flow and information flow, the temperature sensors can convert the physical thermal state of the concrete into a calculable data flow to achieve intelligent control of the concrete heat storage module.

[0049] The concrete heat accumulator should also include a shell, which serves as a full-coverage protective body for the heat storage system. From the outside to the inside, the shell consists of an outer protective layer, a main insulation layer, and an inner lining layer. The main insulation layer can be filled with a composite of vacuum insulation board and aerogel felt, and the inner lining layer is made of stainless steel corrugated board.

[0050] The specific embodiments of this utility model have been described above. It should be understood that this utility model is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the substantive content of this utility model.

Claims

1. An electrically heated concrete accumulator, comprising a concrete accumulator body (1) and a heat exchange tube assembly, the heat exchange tube assembly being composed of multiple heat exchange tubes (2), each heat exchange tube (2) having a heat exchange channel for the flow of a heat exchange medium, and part or all of the tube body of the heat exchange tube (2) being inserted into the concrete accumulator body (1), characterized in that: The concrete heat storage body (1) is also provided with several electric heating channels (3), and electric heating elements are provided in the electric heating channels (3). The gap between the electric heating elements and the electric heating channels (3) is filled with heat-conducting material.

2. An electrically heated concrete thermal accumulator according to claim 1, characterized in that: The electric heating channel (3) is vertically installed inside the concrete heat storage body (1), and several electric heating channels (3) are distributed on both sides of the heat exchange tube (2).

3. The electrically heated concrete thermal storage device of claim 1 wherein: The concrete heat storage body (1) includes multiple concrete heat storage blocks arranged side by side, with a gap between two adjacent concrete heat storage blocks that can absorb the expansion and deformation of the concrete.

4. An electrically heated concrete thermal accumulator according to claim 1, characterized in that: The thermally conductive material is magnesium oxide powder.

5. The electrically heated concrete thermal accumulator of claim 1 wherein: The heat exchange tube (2) is a serpentine tube with a straight tube section (201) and an arc tube section (202) connecting the upper and lower straight tube sections (201). The multiple heat exchange tubes (2) of the heat exchange tube group are parallel to each other. The heat exchange tube group also includes an inlet manifold (4) and an outlet manifold (5). The inlet ends of the multiple heat exchange tubes (2) are all connected to the inlet manifold (4), and the outlet ends of the multiple heat exchange tubes (2) are all connected to the outlet manifold (5).

6. An electrically heated concrete heat accumulator according to claim 5, characterised in that: The outer wall of the straight section (201) of the heat exchange tube (2) is provided with longitudinal fins.

7. An electrically heated concrete heat accumulator as claimed in claim 5, characterized in that: The outer wall of the heat exchange tube (2) is provided with a release agent layer.

8. An electrically heated concrete thermal accumulator according to claim 1, characterized in that: The electric heating element is an electric heating rod.

9. An electrically heated concrete heat accumulator according to claim 1, wherein: The electric heating element is a three-dimensional honeycomb structure woven from electric heating wires.

10. An electrically heated concrete heat accumulator according to claim 1, wherein: Several temperature sensors are embedded in the concrete heat storage body (1).

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