Heat storage / cooler

Abstract

The present invention relates to the field of energy storage devices, and provides a heat storage / cooler. It includes a shell, and at least three layers of solid medium are filled in the shell; the solid medium in the middle layer has one or more of the following properties: the density of the solid medium in the middle layer is greater than the density of the solid medium in other layers, the porosity of the solid medium in the middle layer is less than the porosity of the solid medium in other layers, and the specific heat capacity of the solid medium in the middle layer is greater than the specific heat capacity of the solid medium in other layers. The heat storage / cooler provided by the present invention has a shell filled with solid medium. When in use, the inflowing heat exchange fluid exchanges heat with the solid medium to achieve the storage and release of heat or cold energy; by arranging low-density or high-porosity or low-specific-heat-capacity solid medium on both sides of the middle layer, it is ensured that the mass of the solid medium is reduced, the temperature gradient is increased, the expansion of the internal temperature slope layer is suppressed, and the energy storage efficiency is improved when the heat flux density remains unchanged.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage devices, and in particular to a heat storage / cooling device. Background Art

[0002] At present, the contradiction between energy supply and demand is becoming increasingly prominent, and the share of installed capacity of renewable energy has increased significantly. However, the uncertainty and intermittency of renewable energy will cause unstable output energy. Therefore, energy storage technology has now become a hot topic in the field of renewable energy research.

[0003] In energy storage technology, heat storage and cold storage technology can not only effectively overcome the discontinuity in the energy use process, but also achieve a good spatial and temporal match between energy supply and energy use, and has broad application prospects. Specifically, heat storage technology can be applied to power system peak regulation, aerospace, solar energy utilization, waste heat recovery, heating and air conditioning, and household appliance industry, and cold storage technology can be used in low-temperature power generation, air separation, low-temperature biomedicine, seawater desalination, food processing, cold storage and other occasions. The core component of heat storage and cold storage technology is the heat / cold storage device, and its heat storage and cold storage efficiency directly determines the overall cycle efficiency of the energy storage process.

[0004] The existing heat storage / cooler has a complex structure, adopts a pressure-bearing structure and / or a variety of insulation structures, and improves the energy storage efficiency through insulation devices such as vacuum powder insulation, multi-layer stacked insulation or multi-layer high-pressure stacked bed devices. However, due to the limitations of the insulation devices, the energy storage efficiency is still not high. Summary of the invention

[0005] 1. Technical issues to be resolved

[0006] The purpose of the present invention is to provide a heat storage / cooler to solve the problem of low energy storage efficiency of existing heat storage / coolers. (II) Summary of the invention

[0008] In order to solve the above technical problems, the present invention provides a heat storage / cooling device, comprising a shell,

[0009] The shell is filled with at least three layers of solid phase medium;

[0010] The solid phase medium of the intermediate layer has one or more of the following properties:

[0011] The density of the solid medium in the middle layer is greater than that of the solid medium in other layers, the porosity of the solid medium in the middle layer is less than that of the solid medium in other layers, and the specific heat capacity of the solid medium in the middle layer is greater than that of the solid medium in other layers.

[0012] The shell is provided with a first fluid inlet and a second fluid inlet, and porous media are filled near the first fluid inlet and the second fluid inlet to form two porous media layers, and the two porous media layers are respectively located at both ends of the solid phase medium.

[0013] Wherein, the porous medium includes one or more of porous silicon carbide, porous stainless steel, porous nickel and porous titanium.

[0014] Wherein, the solid phase medium includes one or more of metal, rock, ore, slag and concrete.

[0015] Wherein, a partition is provided between two adjacent layers of the solid phase medium.

[0016] Wherein, the shell comprises an inner wall and an outer wall, and a heat-insulating layer is provided between the inner wall and the outer wall.

[0017] Wherein, the thermal insulation layer comprises one or more of aerogel felt, glass wool, rock wool, expanded perlite and foamed cement.

[0018] Wherein, the materials of the inner wall and the outer wall are titanium, aluminum or steel respectively.

[0019] Wherein, a supporting structure is installed at the bottom of the shell, and the supporting structure is located between the inner wall and the outer wall.

[0020] Wherein, the supporting structure includes a plurality of supporting structures, and the plurality of supporting structures are dispersedly installed at the bottom of the shell.

[0021] (III) Beneficial effects

[0022] The heat storage / cooler provided by the present invention has a shell filled with a solid medium. When in use, the inflowing heat exchange fluid exchanges heat with the solid medium to achieve storage and release of heat energy or cold energy. By arranging a solid medium with high density or low porosity or high specific heat capacity in the middle layer, the heat storage / cold capacity of the heat storage / cooler is increased. By arranging solid medium with low density or high porosity or low specific heat capacity on both sides of the middle layer, it is ensured that when the heat flux density remains unchanged, the mass of the solid medium is reduced, the temperature gradient is increased, the expansion of the internal thermocline layer is suppressed, and the energy storage efficiency is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] 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 or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are 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.

[0024] Figure 1This is a schematic diagram of the structure of a heat storage / cooling device according to an embodiment of the present invention;

[0025] In the figure: 1, middle layer; 2, top layer; 3, bottom layer; 4, first fluid inlet and outlet; 5, second fluid inlet and outlet; 6, porous medium layer; 7, inner wall; 8, outer wall; 9, insulation layer; 10, partition; 11, supporting structure. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are 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.

[0027] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] The heat storage / cooling device provided in the embodiment of the present invention is as follows: Figure 1 As shown, it includes a shell, which is a cavity structure, and is filled with a solid-phase medium. The solid-phase medium is arranged in multiple layers by materials with different densities or porosities or specific heat capacities. The solid-phase medium has at least three layers, namely, the middle layer 1, the top layer 2 and the bottom layer 3, and the top layer 2 and the bottom layer 3 are distributed on opposite sides of the middle layer 1. When the shell is filled with solid-phase media with different porosities, the porosity of the solid-phase medium in the middle layer 1 is smaller than the porosity of the solid-phase media in the top layer 2 and the bottom layer 3; when the solid-phase media filled in the shell have different densities, the density of the solid-phase medium in the middle layer 1 is greater than the density of the solid-phase media in the top layer 2 and the bottom layer 3. Similarly, when the shell is filled with solid-phase media with different specific heat capacities, the specific heat capacity of the solid-phase medium in the middle layer 1 is greater than the specific heat capacity of the solid-phase medium in the top layer 2 and the bottom layer 3. It should be noted that the solid phase medium can also be divided into four layers, five layers or six layers. When it is a four-layer setting, the porosity of the two middle layers of solid phase medium is lower than that of the other two layers or the density is higher than that of the other two layers; when it is a five-layer setting, the density decreases or the porosity increases from the middle to the two sides; when other numbers of layers are set, the same applies and no specific explanation is given.

[0029] In addition, the solid phase medium of the middle layer may satisfy only one of the three conditions of small porosity, high density and large specific heat capacity, or may satisfy two of the three property requirements at the same time, or may satisfy all three property requirements at the same time. This is not specifically limited in the embodiments of the present invention.

[0030] Among them, the solid phase medium of the middle layer 1 can be selected from one or more mixture materials with higher density, such as metal, rock, ore, slag, concrete, etc., and the solid phase medium on the two opposite sides of the middle layer 1 can be selected from metal, non-metal and other materials with lower density. In addition, the solid phase medium of the middle layer 1 can also be selected from one or more mixture materials with lower porosity, such as metal, rock, ore, slag, concrete, etc., and the two sides can be selected from one or more mixture materials with higher porosity, such as metal, rock, ore, slag, concrete, etc. It should be noted that the types of solid phase medium materials of the middle layer 1 and other layers can be the same or different, as long as the density or porosity of the two are different. For example, the solid phase medium of each layer is rock, but the porosity or density of the rock in different layers is different.

[0031] The heat storage / cooler provided in the embodiment of the present invention has a shell filled with a solid medium. When in use, the inflowing heat exchange fluid exchanges heat with the solid medium to achieve storage and release of heat energy or cold energy. The heat exchange fluid and the solid medium produce a natural stratification (i.e., an incline temperature layer) with a large temperature gradient during the heat exchange process. As the heat exchange process proceeds, the thickness of the incline temperature layer will gradually increase, and a thicker incline temperature layer will be formed at the outflow end of the heat exchange fluid. The heat storage / cooler provided in the embodiment of the present invention arranges a low-density or high-porosity solid medium on the top layer 2 and the bottom layer 3 to ensure that the mass of the solid medium is reduced, the temperature gradient is increased, the expansion of the internal incline temperature layer is suppressed, and the energy storage efficiency is improved while the heat flux density remains unchanged.

[0032] Specifically, it includes a first fluid inlet and outlet 4 and a second fluid inlet and outlet 5. The porous medium is filled near the first fluid inlet and outlet 4 and the second fluid inlet and outlet 5 to form two porous medium layers 6. The porous medium layers 6 are also located in the shell and distributed at both ends of the solid phase medium. Therefore, no matter the external fluid enters from the first fluid inlet and outlet 4 or the second fluid inlet and outlet 5, it first passes through the porous medium layer 6 and then exchanges heat with the solid phase medium. With the help of the porous medium, the thickness of the thermocline layer is further reduced and its expansion speed is limited. Among them, the porous medium is a mixture of one or more porous silicon carbide such as ceramics, non-metallic materials such as activated carbon, porous stainless steel, nickel, titanium and other metal materials. The porous medium layer 6 can ensure that the heat exchange fluid flows through the solid phase medium at a uniform flow rate; in addition, compared with the continuous medium, the porous medium has a low relative density, high specific strength, and high specific surface area, which can further reduce the thickness of the thermocline layer and limit its expansion speed.

[0033] Specifically, the shell includes an inner wall 7 and an outer wall 8. There is a gap between the inner wall 7 and the outer wall 8, and the gap is filled with a thermal insulation material to form a thermal insulation layer 9. The solid phase medium and the porous medium are filled in the cavity surrounded by the inner wall 7. Among them, the inner wall 7 and the outer wall 8 are made of metal materials with high strength, stable properties and low thermal conductivity, such as titanium, aluminum, steel, etc., and the two can be made of the same material or different materials. The gap between the inner wall 7 and the outer wall 8 is a vacuum environment, and the thermal insulation layer 9 is made of a thermal insulation material with low thermal conductivity, low density, stable chemical properties and a certain strength, such as aerogel felt, glass wool, rock wool, expanded perlite, foamed cement, etc.

[0034] Among them, a partition 10 is installed between two adjacent layers of solid phase medium, which plays a role of guiding flow while weakening the axial thermal conductivity of the shell, improving the heat storage and cold storage performance, and can also play a supporting role. The partition 10 is a sieve plate, and the sieve holes evenly arranged on the sieve plate are used to improve the filtration performance. The partition 10 is made of metal materials or non-metal materials with high strength, stable properties and low thermal conductivity.

[0035] In addition, the first fluid inlet and outlet 4 and the second fluid inlet and outlet 5 are arranged opposite to each other, and when the heat exchange fluid flows into the shell from the first fluid inlet and outlet 4 or the second fluid inlet and outlet 5, the heat exchange fluid can directly contact with the solid phase medium for heat exchange. In addition, a circulation pipeline can be arranged in the shell, and the two ends of the circulation pipeline are respectively connected to the first fluid inlet and outlet 4 and the second fluid inlet and outlet 5. The heat exchange fluid flows into the circulation pipeline from the first fluid inlet and outlet 4 or the second fluid inlet and outlet 5, and indirectly exchanges heat with the solid phase medium filled between the circulation pipeline and the inner wall 7 of the shell.

[0036] A support structure 11 is installed at the bottom of the shell, and the support structure 11 is located between the inner wall 7 and the outer wall 8. Specifically, the support structure 11 is made of metal or non-metal material with high compressive strength, stable chemical properties and low thermal conductivity, and can be in a circular ring shape, sleeved on the outer side of the inner wall 7 to provide support force, or multiple support blocks can be provided to provide support force through multi-point support to support the medium filled in the shell.

[0037] The heat exchange fluid in the embodiment of the present invention may be a gas or a liquid or a gas-liquid mixture.

[0038] The use process is as follows: In the early stage of energy storage / release, solid phase media and separators 10 with different densities, different specific heat capacities or different porosities are loaded in layers in order to complete the accumulation of solid phase media.

[0039] In the heat storage stage, the high-temperature heat exchange fluid enters from the first fluid inlet and outlet 4 and enters the solid medium through the porous medium layer 6. The high-temperature heat exchange fluid successively passes through the gaps of the solid medium with different densities, different porosities or different specific heat capacities, and directly or indirectly contacts the solid medium. After heat exchange, the temperature is reduced, and the low-temperature fluid after cooling flows out from the second fluid inlet and outlet 5. The layered solid medium absorbs heat to obtain thermal energy and the temperature rises. When the temperature of the heat exchange fluid drops to the low-temperature cut-off temperature, the first fluid inlet and outlet 4 and the second fluid inlet and outlet 5 are closed, and the heat preservation stage is entered, so that the heat carried by the high-temperature heat exchange fluid is stored in the solid medium to complete the heat storage.

[0040] In the heat release stage, the low-temperature heat exchange fluid enters the shell through the second fluid inlet and outlet 5, flows through the porous medium layer 6, exchanges heat with the solid medium, obtains the thermal energy stored in the solid medium, and flows out with the temperature increased, while the temperature of the solid medium decreases. When the temperature of the outflowing heat exchange fluid reaches the high temperature cut-off temperature, the first fluid inlet and outlet 4 and the second fluid inlet and outlet 5 are closed to complete the heat release.

[0041] In the cold storage stage, the low-temperature heat exchange fluid enters from the second fluid inlet and outlet 5 and enters the shell through the porous medium layer 6. The low-temperature heat exchange fluid successively passes through the gaps of solid phase media with different densities, porosities or specific heat capacities, and directly or indirectly contacts the solid particles. After heat exchange, the temperature rises, and the high-temperature fluid after the temperature rise flows out of the heat storage / cooling device from the first fluid inlet and outlet 4. After the stratified solid phase medium obtains cold energy, the temperature decreases. When the temperature of the outflowing heat exchange fluid reaches the high temperature cut-off temperature, the first fluid inlet and outlet 4 and the second fluid inlet and outlet 5 are closed to enter the insulation stage, and the cold storage is completed.

[0042] In the cooling stage, the high-temperature heat exchange fluid enters the shell from the second fluid inlet and outlet 5, flows through the porous medium layer 6, and exchanges heat with the low-temperature solid medium of different density or porosity. After obtaining the cold energy of the solid medium, the temperature of the heat exchange fluid decreases and flows out of the shell, while the temperature of the solid medium increases. When the temperature of the outflowing heat exchange fluid reaches the low-temperature cut-off temperature, the first fluid inlet and outlet 4 and the second fluid inlet and outlet 5 are closed to complete the cooling.

[0043] The heat storage / cooler provided in the embodiment of the present invention is suitable for occasions with large heat exchange temperature differences and frequent cold and heat storage, and can effectively weaken the nonlinear migration and expansion of the inclined temperature layer along the flow direction of the heat exchange fluid caused by the gradual change of the temperature of the solid medium at different positions in the heat storage / cooler, thereby improving the heat exchange efficiency.

[0044] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A heat storage / cooling device, comprising a shell, characterized in that: The shell is filled with at least three layers of solid phase medium, and a partition is provided between two adjacent layers of the solid phase medium; The solid phase medium of the middle layer has the following properties: The density of the solid phase medium in the middle layer is greater than the density of the solid phase medium in other layers, the porosity of the solid phase medium in the middle layer is less than the porosity of the solid phase medium in other layers, and the specific heat capacity of the solid phase medium in the middle layer is greater than the specific heat capacity of the solid phase medium in other layers; The shell is provided with a first fluid inlet and a second fluid inlet, and porous media are filled near the first fluid inlet and the second fluid inlet to form two porous media layers, and the two porous media layers are respectively located at two ends of the solid phase medium.

2. The heat storage / cooling device according to claim 1, characterized in that: The porous medium includes one or more of porous silicon carbide, porous stainless steel, porous nickel and porous titanium.

3. The heat storage / cooling device according to claim 1, characterized in that: The solid phase medium includes one or more of metal, rock, ore, slag and concrete.

4. The heat storage / cooling device according to claim 1, characterized in that: The shell comprises an inner wall and an outer wall, and a heat-insulating layer is arranged between the inner wall and the outer wall.

5. The heat storage / cooling device according to claim 4, characterized in that: The thermal insulation layer comprises one or more of aerogel felt, glass wool, rock wool, expanded perlite and foamed cement.

6. The heat storage / cooling device according to claim 4, characterized in that: The inner wall and the outer wall are made of titanium, aluminum or steel respectively.

7. The heat storage / cooling device according to claim 4, characterized in that: A supporting structure is installed at the bottom of the shell, and the supporting structure is located between the inner wall and the outer wall.

8. The heat storage / cooling device according to claim 7, characterized in that: The supporting structures include a plurality of supporting structures, and the plurality of supporting structures are dispersedly installed at the bottom of the shell.

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