A composite heat storage structure for solid heat storage

Abstract

The present invention discloses a composite heat storage structure for solid heat storage, comprising: a solid heat storage body, the solid heat storage body is a cubic hollow structure, the solid heat storage body comprises: an upper cover and a bottom, the upper cover is a heat source side reinforced heat absorption plate, the inner surface of the bottom is provided with a heat release T-shaped reinforcement rib, and the outer surface of the bottom is provided with a heat release air duct; at least one liquid-solid phase change heat storage unit is arranged inside the solid heat storage body; a high temperature insulation layer and a low temperature insulation layer are arranged in sequence on the outer surface of the solid heat storage body. The technical solution of the invention is adopted to solve the problem of small heat storage capacity per unit volume in the current solid heat storage.

Description

Technical Field

[0001] The invention belongs to the technical field of energy utilization and heat storage, and in particular relates to a composite heat storage structure for improving the performance of a solid heat storage device. Background Art

[0002] In the field of energy utilization, when there is a time-space mismatch between energy supply and energy use, energy storage technology is needed. Among various energy storage technologies, heat storage technology is the most widely used technical branch. According to the different heat storage temperatures, heat storage technologies can be roughly divided into low-temperature heat storage and medium- and high-temperature heat storage. Low-temperature heat storage is mainly aimed at the fields of solar thermal utilization and building energy conservation, and usually uses phase change materials such as salt solutions, hydrated salts, paraffin, and fatty acids as heat storage media; medium- and high-temperature heat storage is widely used in solar thermal power generation, industrial waste heat utilization, nuclear power, and power grid energy storage. It mainly uses heat transfer oil, molten salt and high-temperature resistant solid materials as heat storage media. Among various medium- and high-temperature heat storage technologies, solid heat storage has many advantages such as high heat storage temperature, simple structure, and low cost. It is the most widely used heat storage technology in actual engineering. Especially in recent years, due to the increasingly serious environmental problems represented by "smog", the heat storage electric boiler technology using solid heat storage materials has become an important technical choice for "non-coal heating". In addition, due to the limitations of thermal oil and the high technical threshold of molten salt, people are also exploring the use of solids as heat storage materials for solar thermal power generation.

[0003] For a heat storage system, unit heat storage capacity is a very important indicator, which has a great impact on the compactness and economy of its structure. The factors affecting its unit heat storage capacity mainly include heat storage temperature, specific heat and density of heat storage materials, latent heat of phase change and other factors. However, this indicator reflects the comprehensive heat storage capacity of the heat storage material, which has a certain ideality and cannot fully represent the actual heat storage capacity of the heat storage structure. The actual heat storage capacity of a heat storage system also depends on the heat storage and heat release characteristics of the heat storage structure, which is related to the thermal properties of the heat storage material and the specific structure of the heat storage body. A reasonable heat storage system needs to comprehensively consider factors such as heat storage capacity and heat storage and release requirements, select heat storage materials and design heat storage structures.

[0004] For solid thermal storage technology, the thermal storage materials usually used are refractory materials of different components. Such materials have the advantages of high thermal storage temperature, low price, and easy processing and molding. However, their disadvantages are low thermal conductivity and specific heat, which makes the thermal storage system require a large space. At the same time, during the process of heat storage and heat release, the thermal storage structure will have a certain temperature distribution in space, which further reduces its thermal storage capacity. At present, solid thermal storage has the problem of small thermal storage capacity per unit volume. Therefore, how to improve the thermal storage capacity of solid thermal storage is an important technical problem that needs to be solved urgently, especially the optimization and design of thermal storage structure. Summary of the invention

[0005] In view of the problem that the heat storage capacity per unit volume of current solid heat storage is relatively small, the purpose of the present invention is to design a composite heat storage structure that can be applied to solid heat storage.

[0006] To achieve the above object, the present invention adopts the following technical solution:

[0007] A composite heat storage structure for solid heat storage comprises: a solid heat storage body, which is a cubic hollow structure, and comprises: an upper cover and a bottom, wherein the upper cover is a heat source side reinforced heat absorption plate, the inner surface of the bottom is provided with a heat-releasing T-shaped reinforcing rib, and the outer surface of the bottom is provided with a heat-releasing air duct; at least one liquid-solid phase change heat storage unit is arranged inside the solid heat storage body; and a high-temperature insulation layer and a low-temperature insulation layer are arranged in sequence on the outer surface of the solid heat storage body.

[0008] Preferably, the heat source side enhanced heat exchange plate comprises: a heat absorbing panel, the upper surface of the heat absorbing panel is provided with a high-absorption refractory coating, the bottom surface of the heat absorbing panel is provided with heat absorbing plate strengthening ribs, the heat absorbing plate strengthening ribs are located in the solid heat storage body, and heat absorbing plate side panels are provided on both sides of the heat absorbing panel; one side of the upper surface of the heat absorbing panel is a heat source.

[0009] Preferably, the liquid-solid phase change heat storage unit is a packaging structure, and the liquid-solid phase change heat storage unit comprises: a rectangular packaging shell and a packaging cover; a high-temperature side strengthening rib is provided on the inner upper surface of the rectangular packaging shell; a low-temperature side strengthening rib is provided on the inner lower surface of the rectangular packaging shell, and the high-temperature side strengthening rib and the low-temperature side strengthening rib are alternately distributed.

[0010] Preferably, the heat source is an electric heater, which is arranged on the high-absorption refractory coating and is connected to a heating power source via a cable.

[0011] Preferably, the heat source is high temperature air or heat transfer oil.

[0012] Preferably, the liquid-solid phase change unit is arranged in an integrated or distributed manner.

[0013] The present invention combines a liquid-solid phase change heat storage unit with a solid heat storage body, making full use of the advantages of the high heat storage capacity of the liquid-solid phase change heat storage unit, and adopting a packaging structure, which not only matches the heat transfer characteristics of the solid heat storage body, but also avoids many shortcomings of phase change heat storage in practical applications, significantly improving the heat storage per unit volume of the solid heat storage structure; at the same time, enhanced heat transfer measures are adopted to make the heat storage and heat release process of the composite heat storage structure smoother, thereby improving the heat storage efficiency; in addition, the composite heat storage structure can be adopted as a modular combination, which has a compact structure and a simple processing technology. The composite heat storage structure and the entire heat storage device can be flexibly designed according to different application scenarios, greatly increasing flexibility. The new composite heat storage structure of the present invention effectively improves the heat storage capacity of the solid heat storage device and can promote the application of solid heat storage in practical engineering. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 , schematic diagram of composite thermal storage structure applied to solid thermal storage;

[0015] Figure 2 , a schematic diagram of the heat source side heat absorption plate structure of the composite heat storage structure applied to solid heat storage;

[0016] Figure 3 , schematic diagram of the liquid-solid phase change unit structure of the composite thermal storage structure applied to solid thermal storage;

[0017] Figure 4 , Schematic diagram of composite thermal storage structure using multi-layer liquid-solid phase change units;

[0018] Figure 5 , schematic diagram of a composite thermal storage structure using multiple dispersed liquid-solid phase change units;

[0019] Figure 6 , schematic diagram of the combined structure of the composite thermal storage module;

[0020] Figure 7 , schematic diagram of cubic composite thermal storage structure using electric heating and liquid heat extraction;

[0021] Figure 8 , schematic diagram of a cubic composite thermal storage structure using electric heating and air heating;

[0022] Fig. 9 , schematic diagram of cubic composite thermal storage structure using liquid heating and heat extraction;

[0023] Fig.10 , schematic diagram of a cubic composite thermal storage structure using liquid heating and air heat extraction.

[0024] in, Figures 1 to 10In: 1-electric heating tube; 2-cable; 3-reinforced heat absorption plate on the heat source side; 4-liquid-solid phase change heat storage unit; 5-solid heat storage body; 6-heat release enhanced heat exchange tube; 7-high temperature insulation layer; 8-low temperature insulation layer; 9-heat absorption panel; 10-refractory coating layer; 11-heat absorption plate reinforcement rib; 12-heat absorption plate side plate; 13-packaging unit shell; 14-packaging cover; 15-high temperature side reinforcement rib of packaging unit; 16-low temperature side reinforcement rib of packaging unit; 17-heat release T-shaped reinforcement rib; 18-heat release air duct; 19-heat release external connecting pipe; 20-heat storage enhanced heat exchange tube; 21-heat storage external connecting pipe. DETAILED DESCRIPTION

[0025] The composite heat storage structure designed by the present invention can be used in many fields such as industrial waste heat utilization, building heating, grid energy storage, solar thermal power generation, etc. In the specific implementation scheme, different structural forms can be flexibly selected according to different application occasions. The preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0026] like Figure 1 , 2 As shown in Figure 3, a composite heat storage structure used for solid heat storage includes: a solid heat storage body, which is a cubic hollow structure, and the solid heat storage body includes: an upper cover and a bottom, the upper cover is a heat source side reinforced heat absorption plate, the heat source side reinforced heat absorption plate is a "U" shape, the inner surface of the bottom is provided with a heat release T-shaped reinforcement rib, and the outer surface of the bottom is provided with a heat release air duct; at least one liquid-solid phase change heat storage unit is arranged inside the solid heat storage body, and the liquid-solid phase change heat storage unit is fixed on the inner wall of the solid heat storage body; a high-temperature insulation layer and a low-temperature insulation layer are arranged on the outer surface of the solid heat storage body in sequence.

[0027] The heat source side enhanced heat exchange plate comprises: a heat absorbing panel, the upper surface of the heat absorbing panel is provided with a high-absorption refractory coating for improving the panel's ability to absorb thermal radiation, the bottom surface of the heat absorbing panel is provided with heat absorbing plate reinforcing ribs, the heat absorbing plate reinforcing ribs are located in the solid heat storage body, and are used to improve the heat transfer capacity between the reinforcing plate and the solid heat storage body, and heat absorbing plate side plates are provided on both sides of the heat absorbing panel; one side of the upper surface of the heat absorbing panel is a heat source, and the heat source is an electric heater, which is provided on the high-absorption refractory coating and is connected to a heating power source through a cable, and the heat source can also be high-temperature air or heat-conducting oil.

[0028] The liquid-solid phase change heat storage unit is a packaging structure, and the liquid-solid phase change heat storage unit comprises: a rectangular packaging shell and a packaging cover; the upper surface of the inner side of the rectangular packaging shell is provided with a high-temperature side reinforcement rib; the lower surface of the inner side of the rectangular packaging shell is provided with a low-temperature side reinforcement rib, and the high-temperature side reinforcement rib and the low-temperature side reinforcement rib are alternately distributed. The materials used in the liquid-solid phase change heat storage unit include metals, alkalis, compound salts and mixed salts. The arrangement form of the liquid-solid phase change unit is integral or distributed.

[0029] Example 1

[0030] See also Figure 4 In this embodiment, the heat source is in the form of electric heating, the heat-releasing medium is air, and the liquid-solid phase change unit adopts a dispersed multilayer structure. The electric heating tube connected to the cable transfers heat to the heat source side to strengthen the heat absorption plate. A double-layer liquid-solid phase change heat storage unit is set in the solid heat storage body, and a liquid-solid phase change heat storage unit is set on the high-temperature side. The selected heat storage material should have the characteristics of a high phase change point and a large phase change latent heat. A liquid-solid phase change heat storage unit is set on the low-temperature side. The selected heat storage material should have the characteristics of a low phase change point and a large phase change latent heat. Through the double-layer structure, the heat storage temperature difference in the middle and late stages of heat storage is increased, which can not only increase the heat storage capacity but also improve the heat transfer performance of the heat storage structure; on the heat release side, air flows through the heat release air duct to exchange heat with the surface of the solid heat storage body. The heat release side T-shaped strengthening ribs set at the bottom of the solid heat storage body are used to improve the heat exchange capacity between the heat storage body and the air. This structure is particularly suitable for the field of building heating.

[0031] Example 2

[0032] See the plan Figure 5 In this embodiment, the heat source is in the form of electric heating, the heat-releasing medium is air, and the liquid-solid phase change unit adopts a dispersed linear structure. The electric heating tube transfers heat to the heat source side reinforcing heat absorption plate; a dispersed linear arrangement of liquid-solid phase change heat storage unit is arranged in the solid heat storage body. The dispersed arrangement significantly increases the contact area between the liquid-solid phase change unit and the solid heat storage body, which is beneficial to heat transfer; on the heat release side, air flows through the heat release air duct to exchange heat with the surface of the solid heat storage body. The heat release side T-shaped reinforcing ribs arranged at the bottom of the solid heat storage body are used to improve the heat exchange capacity between the heat storage body and the air. This structure is particularly suitable for the field of building heating.

[0033] Example 3

[0034] See the plan Figure 6 In this embodiment, the heat source is electric heating, the heat-releasing medium is air, and multiple heat storage structures are modularly combined. Any two heat storage structures are arranged axially symmetrically, and multiple heat storage structures form alternating heating chambers and heat-releasing air ducts. High-temperature insulation layers and low-temperature insulation layers are arranged on the sides of multiple heat storage structures. This implementation scheme has a simple structure and can flexibly provide different heat storage device capacities.

[0035] Example 4

[0036] See the plan Figure 7In this embodiment, the heat source is electric heating, the heat-releasing medium is heat-conducting oil or water, and the liquid-solid phase change unit adopts an integral structure. The electric heating pipe transfers heat to the heat-source side enhanced heat-absorbing plate, and an integrally arranged liquid-solid phase change heat storage unit is arranged in the solid heat storage body; on the heat-releasing side, a heat-releasing enhanced heat exchange pipe is arranged at a specific position of the solid heat storage body, and is connected to the user side through a heat-releasing external connection pipe. This structure is suitable for the fields of power grid energy storage and building heating.

[0037] Example 5

[0038] See the plan Figure 8 In this embodiment, the heat source is electric heating, the heat-releasing medium is air, the liquid-solid phase change unit adopts an integral structure, the electric heating pipe transfers heat to the heat source side strengthening heat absorption plate, and the integrally arranged liquid-solid phase change heat storage unit is arranged in the solid heat storage body 5; on the heat-releasing side, the air flows through the heat-releasing air duct to exchange heat with the surface of the solid heat storage body, and the heat-releasing side T-shaped strengthening ribs arranged at the bottom of the solid heat storage body are used to improve the heat exchange capacity between the heat storage body and the air. This structure is suitable for the field of building heating.

[0039] Example 6

[0040] See the plan Fig. 9 In this embodiment, the heat source is heat transfer oil, the heat release medium is heat transfer oil or water, and the liquid-solid phase change unit adopts an integral structure. On the heat storage side, a heat storage enhanced heat exchange pipe is set at a specific position of the solid heat storage body, and is connected to the heat source side through a heat storage external connection pipe; an integrally arranged liquid-solid phase change heat storage unit is set inside the solid heat storage body; on the heat release side, a heat release enhanced heat exchange pipe is set at a specific position of the solid heat storage body, and is connected to the user side through a heat release external connection pipe. This structure is suitable for the field of industrial waste heat utilization and solar thermal power generation.

[0041] Example 7

[0042] See the plan Fig.10 In this embodiment, the heat source is in the form of heat transfer oil, the heat release medium is air, and the liquid-solid phase change unit adopts an integral structure. On the heat storage side, a heat storage enhanced heat exchange pipe is set at a specific position of the solid heat storage body, and is connected to the heat source side through a heat storage external connection pipe; an integrally arranged liquid-solid phase change heat storage unit is set in the solid heat storage body; on the heat release side, air flows through the heat release air duct to exchange heat with the solid heat storage surface, and the heat release side T-shaped strengthening ribs set at the bottom of the solid heat storage body are used to improve the heat exchange capacity between the heat storage body and the air. This structure is suitable for the fields of industrial waste heat utilization and solar heating.

Claims

1. A composite heat storage structure for solid heat storage, characterized in that: include: A solid heat storage body, which is a cubic hollow structure, comprises: an upper cover and a bottom, wherein the upper cover is a heat source side reinforced heat absorbing plate, the inner surface of the bottom is provided with a heat-releasing T-shaped reinforcing rib, and the outer surface of the bottom is provided with a heat-releasing air duct; at least one liquid-solid phase change heat storage unit is arranged inside the solid heat storage body; a high-temperature heat-insulating layer and a low-temperature heat-insulating layer are arranged in sequence on the outer surface of the solid heat storage body; The heat source side enhanced heat exchange plate comprises: a heat absorbing panel, the upper surface of the heat absorbing panel is provided with a high-absorption refractory coating, the bottom surface of the heat absorbing panel is provided with heat absorbing plate strengthening ribs, the heat absorbing plate strengthening ribs are located in the solid heat storage body, and heat absorbing plate side plates are provided on both sides of the heat absorbing panel; one side of the upper surface of the heat absorbing panel is a heat source.

2. The composite heat storage structure for solid heat storage according to claim 1, characterized in that: The liquid-solid phase change heat storage unit is a packaging structure, and the liquid-solid phase change heat storage unit comprises: a rectangular packaging shell and a packaging cover; the upper surface of the inner side of the rectangular packaging shell is provided with a high-temperature side strengthening rib; the lower surface of the inner side of the rectangular packaging shell is provided with a low-temperature side strengthening rib, and the high-temperature side strengthening rib and the low-temperature side strengthening rib are alternately distributed.

3. The composite heat storage structure for solid heat storage according to claim 1, characterized in that: The heat source is an electric heater, which is arranged on the high-absorption refractory coating and is connected to a heating power source through a cable.

4. The composite heat storage structure for solid heat storage according to claim 1, characterized in that: The heat source is high temperature air or heat transfer oil.

5. The composite heat storage structure for solid heat storage according to claim 1, characterized in that: The arrangement form of the liquid-solid phase change unit is integral or dispersed.

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