Solar cross-seasonal heat storage system

Abstract

According to the solar cross-seasonal heat storage system, a heat storage water tank is provided with a cylindrical main tank body and an auxiliary tank body which is arranged at the bottom of the main tank body and is of an inverted cone structure, and the bottom of the heat storage water tank is provided with a conical wall face with a certain inclination angle so that fluid can be prevented from flowing; convective mixing between low-temperature water at the bottom of the heat storage water tank and high-temperature water in the upper middle of the heat storage water tank can be reduced, the internal convection effect strength is weakened, mixing of cold water and hot water is reduced, and the hot water yield can be increased. And moreover, the flow deflectors for reducing the water flow speed are arranged in the main tank body of the heat storage water tank, the water flow can be blocked by the flow deflectors, the flow speed is relatively reduced, the natural convection heat exchange intensity in the water tank is smaller, and the generated heat loss is smaller, so that the flow deflectors are beneficial to improving the heat storage efficiency of the heat storage water tank. The solar cross-seasonal heat storage system has the advantages of being high in heat storage efficiency and small in heat loss.

Description

Technical Field

[0001] The present invention relates to the technical field of inter-seasonal heat storage, and in particular to a solar inter-seasonal heat storage system. Background Art

[0002] The efficient utilization of renewable energy has become a crucial component of building a low-carbon society. Globally, solar energy is the most widely distributed of all clean, renewable energy sources, boasting significant advantages such as being pollution-free, inexhaustible, and inexhaustible. To fully utilize solar energy, it is necessary to collect and store it when there is no heat demand, thereby increasing its year-round utilization rate. Currently, long-term, inter-seasonal solar thermal storage technology is a hot topic of research.

[0003] Solar thermal storage across the seasons is a key technology for overcoming the "summer surplus and winter deficit" of solar energy. Underground thermal storage is a widely used energy storage technology. Sensible heat storage, which uses cylindrical water storage tanks as the heat storage medium and water as the heat storage medium, offers significant advantages over other thermal storage methods, such as buried pipes and gravel, including simple charging and discharging, large heat capacity, excellent heat exchange, low cost, and a wide range of raw material sources. As a result, it is being widely promoted in the thermal storage field.

[0004] However, simply using a cylindrical heat storage tank to store hot water has low heat storage efficiency, large heat loss, and small hot water output, which in turn leads to low heat storage efficiency and large heat loss in the existing solar inter-seasonal heat storage system. Summary of the Invention

[0005] The purpose of the present invention is to provide a solar inter-seasonal heat storage system to solve the problems of low heat storage efficiency and large heat loss in existing solar inter-seasonal heat storage systems.

[0006] To achieve the above objectives, the present invention provides a solar inter-seasonal heat storage system, comprising a solar heat collection subsystem, an underground heat storage subsystem, and a heating subsystem. The underground heat storage subsystem comprises a heat storage tank buried underground, the outer wall of which is coated with a heat insulation material.

[0007] The hot water storage tank comprises a cylindrical main body and a secondary body arranged at the bottom of the main body. The secondary body is in an inverted cone structure, and the top of the secondary body is connected to the bottom of the main body. The main body is provided with a guide plate to reduce the water flow speed.

[0008] The top of the main box body is provided with a heat storage water inlet and an exhaust port, the heat storage water inlet is arranged opposite to the top of the guide plate; the heat storage water inlet is connected to the solar heat collection subsystem through a pipeline;

[0009] The bottom end of the auxiliary box is provided with a water outlet; the water outlet is connected to the solar heat collection subsystem through a pipeline;

[0010] The main box body and / or the auxiliary box body is provided with at least one heat release drain outlet, and the heat release drain outlet is connected to the heating subsystem through a pipeline.

[0011] Optionally, the auxiliary box is an inverted cone structure.

[0012] Optionally, the auxiliary box is an inverted pyramid structure.

[0013] Optionally, the cone bottom angle of the auxiliary box is [40°, 70°].

[0014] Optionally, the guide plate is a spiral structure extending axially along the main box body; the outer edge of the guide plate is arranged in contact with the inner wall of the main box body, the middle part of the guide plate has a fixed shaft, the inner edge of the guide plate is integrally arranged with the outer surface of the fixed shaft, and the top end of the fixed shaft is fixedly connected to the bottom of the main box body.

[0015] Optionally, a plurality of phase-change heat storage tubes are provided in the heat storage tank, the phase-change heat storage tubes are extended axially along the main body, and the phase-change heat storage tubes are fixedly installed on the guide plate.

[0016] Optionally, the phase change heat storage tube is filled with a plurality of phase change materials with different phase change temperatures in layers; from bottom to top, the plurality of phase change materials with different phase change temperatures are filled in the phase change heat storage tube in layers in ascending order according to the phase change temperature.

[0017] Optionally, the phase-change heat storage tube is arranged to extend in a circuitous manner in a vertical plane.

[0018] Optionally, the main box body and the auxiliary box body are both provided with a plurality of heat release drain outlets, and the plurality of heat release drain outlets are arranged at intervals up and down.

[0019] Optionally, the solar heat collection subsystem includes a solar cooker, the solar cooker is arranged on a tracking base, the water outlet is connected to a heating cavity arranged at the focus of the solar cooker through a first pipe, and the first pipe is provided with a water pump and a valve;

[0020] The heating cavity is communicated with the heat storage water inlet through a second pipe, and a valve is provided on the second pipe.

[0021] The beneficial effects of the present invention are embodied in:

[0022] The solar inter-seasonal heat storage system provided in the present application has a hot water storage tank having a cylindrical main tank body and a sub-tank body with an inverted cone structure arranged at the bottom of the main tank body. The conical wall surface with a certain inclined angle at the bottom of the hot water storage tank will hinder the flow of fluid, which can reduce the convective mixing between the low-temperature water at the bottom of the hot water storage tank and the high-temperature water in the upper part of the hot water storage tank, weaken the internal convection intensity, reduce the mixing of cold and hot water, and increase the hot water output.

[0023] In addition, the main body of the hot water storage tank is equipped with a guide plate to reduce the water flow rate. The water flow will be hindered by the guide plate, and the flow rate will be relatively reduced. The smaller the natural convection heat exchange intensity inside the water tank, the smaller the heat loss generated. Therefore, the guide plate is beneficial to improving the heat storage efficiency of the hot water storage tank.

[0024] In summary, since the heat storage tank of the solar inter-seasonal heat storage system provided by the present application has the above advantages, the solar inter-seasonal heat storage system of the present application has the advantages of high heat storage efficiency and less heat loss. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly describes the drawings required for the specific embodiments or the description of the prior art. Similar elements or parts are generally identified by similar reference numerals throughout the drawings. Elements or parts in the drawings are not necessarily drawn to scale.

[0026] The accompanying drawings herein are incorporated into and constitute a part of the specification, illustrate embodiments consistent with the present application, and together with the specification, are used to explain the principles of the present application. For those skilled in the art, other drawings can be derived from these drawings without inventive effort.

[0027] Figure 1 A schematic structural diagram of a solar inter-seasonal heat storage system provided by an embodiment of the present invention;

[0028] Figure 2 A schematic structural diagram of a heat storage tank provided by an embodiment of the present invention;

[0029] Figure 3 A schematic diagram of the internal structure of a heat storage tank provided by an embodiment of the present invention;

[0030] Figure 4 A schematic diagram of the internal structure of a secondary box provided in an embodiment of the present invention;

[0031] Figure 5 A schematic structural diagram of a guide plate provided in an embodiment of the present invention;

[0032] Figure 6A schematic structural diagram of a phase-change heat storage tube provided in an embodiment of the present invention.

[0033] The purpose of this application, its features, and advantages will be further described in conjunction with the embodiments and with reference to the accompanying drawings. The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and the accompanying text are not intended to limit the scope of the present application in any way, but rather to illustrate the concepts of this application to those skilled in the art by reference to specific embodiments. DETAILED DESCRIPTION

[0034] The following embodiments of the technical solution of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention and are therefore only examples and are not intended to limit the scope of protection of the present invention.

[0035] It should be noted that, unless otherwise specified, the technical or scientific terms used in this application should have the common meanings understood by those skilled in the art to which the present invention belongs.

[0036] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0037] In addition, the terms "first," "second," etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. In the description of the present invention, "plurality" means more than two, unless otherwise specifically defined.

[0038] In this application, unless otherwise expressly specified or limited, terms such as "mounted," "connected," "connect," and "fixed" should be understood in a broad sense. For example, they may refer to fixed or detachable connections, or integration; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0039] In this application, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0040] like Figure 1 As shown, an embodiment of the present invention provides a solar inter-seasonal heat storage system, including a solar heat collection subsystem 100, an underground heat storage subsystem 200, and a heating subsystem 300. The solar heat collection subsystem 100 can be installed on the roof, and the underground heat storage subsystem 200 includes a heat storage tank buried underground. The heat storage tank can be buried 10m-15m underground. The outer wall of the heat storage tank is coated with a heat insulation material to insulate the heat storage tank. The heat insulation material can be made of a material such as sponge. It is understood that the embodiment of the present application does not specifically limit the material of the heat insulation material. All other suitable materials with heat insulation functions can be used as the heat insulation material in this embodiment.

[0041] During the non-heating season, the system stores the heat obtained by the solar thermal collection subsystem 100 in the form of sensible heat in the hot water storage tank; during the heating season, the hot water in the hot water storage tank is sent to the heating subsystem 300 at the end of the building for heating, thereby achieving cross-seasonal heating.

[0042] Specifically, such as Figure 1 As shown, the solar thermal collection subsystem 100 includes a solar cooker 11 mounted on a spot-tracking base 12. A heating chamber 13, located at the focal point of the solar cooker 11, communicates with a water outlet 6 at the bottom of a hot water storage tank via a first pipe equipped with a water pump and a valve. The heating chamber 13 communicates with a thermal water inlet 4 at the top of the hot water storage tank via a second pipe, also equipped with a valve. The solar cooker 11 reflects sunlight to heat water within the heating chamber 13. After heating to a predetermined temperature, the water is discharged through the second pipe into the hot water storage tank for storage. The solar cooker 11 is mounted on the spot-tracking base 12, which has a spot-tracking function that allows the solar cooker 11 to face the sun for maximum sunlight exposure, thereby improving the solar cooker's efficiency in utilizing solar energy. It should be understood that the present embodiments do not impose any specific limitations on the structure of the spot-tracking base 12; any device and / or system capable of enabling the solar cooker 11 to achieve spot-tracking functionality may be used.

[0043] The lower part of the hot water storage tank stores low-temperature water. After being discharged from the water outlet 6, the low-temperature water is pumped into the heating chamber 13 by the water pump installed on the first pipe. It is then heated by the external solar cooker 11 to become high-temperature water that meets a certain temperature quality. It returns to the hot water storage tank for storage. The hot water storage tank will inevitably produce a certain amount of heat loss during the heat storage and release process. As the depth changes, the internal temperature of the water tank will drop. At the same time, there is a certain density difference between the high and low temperature fluids, so internal flow of the hot water will occur inside the tank. In other words, there is a natural convection effect of the fluid in the water tank. There is a mixing layer between the two called the thermocline layer. The thinner the thickness of the thermocline layer, the higher the hot water output.

[0044] In order to reduce the natural convection of high and low temperature fluids inside the hot water storage tank, in this embodiment, Figure 2 As shown, the hot water storage tank comprises a cylindrical main body 1 and a secondary body 2 mounted at the bottom of the main body 1. The secondary body 2 has an inverted conical structure, with the top of the secondary body 2 and the bottom of the main body 1 intersecting and communicating with each other. The secondary body 2 has a tapered wall surface with a certain angle, which impedes fluid flow and reduces convective mixing between the low-temperature water at the bottom of the hot water storage tank and the high-temperature water in the upper middle portion of the hot water storage tank. This weakens the internal convection, reduces mixing of cold and hot water, and increases the hot water output.

[0045] In an exemplary embodiment, the auxiliary housing 2 can have an inverted cone structure or an inverted pyramid structure, such as an inverted triangular pyramid structure, an inverted quadrangular pyramid structure, an inverted pentagonal pyramid structure, etc. The main housing 1 can have a cylindrical structure or a square column structure. The present application embodiment is described by taking the main housing 1 having a cylindrical structure and the auxiliary housing 2 having an inverted cone structure as an example.

[0046] In this embodiment, Figure 4 As shown, the cone bottom angle θ of the auxiliary box 2 is [40°, 70°], and the preferred cone bottom angle θ is 50°.

[0047] The top of the main box 1 is provided with a heat storage water inlet 4 and an exhaust port 5. The heat storage water inlet 4 is connected to the heating cavity 13 of the solar thermal collection subsystem 100 through a second pipe. The exhaust port 5 is used to discharge the gas in the heat storage tank. The bottom end of the auxiliary box 2 is provided with a water outlet 6. The water outlet 6 is connected to the heating cavity 13 of the solar thermal collection subsystem 100 through a first pipe. At least one heat release drain port 7 is provided on the main box 1 and / or the auxiliary box 2. The heat release drain port 7 is connected to the heating subsystem 300 through a pipe. The heat release drain port 7 is used to release hot water and send the hot water in the heat storage tank to the heating subsystem 300 at the end of the building for heating.

[0048] In an exemplary embodiment, Figure 3As shown, the main body 1 also has a guide plate 3 inside to reduce the water flow rate. When the water flows downward, it will be hindered by the guide plate 3, and the flow rate will be relatively reduced. The smaller the natural convection heat exchange intensity inside the water tank, the smaller the heat loss generated. Therefore, the guide plate 3 is conducive to improving the heat storage efficiency of the hot water storage tank. It should be noted that the technical solution of the present application reduces the water flow rate by providing the guide plate 3 inside the main body 1 of the hot water storage tank, rather than reducing the water flow rate by tilting the side wall of the main body 1. This can reduce the contact area between the water flow and the side wall of the main body 1, thereby reducing the heat exchange area between the water flow and the side wall of the main body 1, reducing the heat exchange rate, and enabling the hot water storage tank to better maintain heat.

[0049] Specifically, in an exemplary embodiment, Figure 3 and Figure 5 As shown, the guide plate 3 is a spiral structure extending along the axial direction of the main housing 1. The heat storage water inlet 4 is arranged opposite the top of the guide plate 3. This ensures that there are no dead angles from top to bottom when the water flows along the guide plate 3. The outer edge of the guide plate 3 is arranged in contact with the inner wall of the main housing 1 to form a seal between the outer edge of the guide plate 3 and the inner wall of the main housing 1. The middle part of the guide plate 3 has a fixed shaft 8. The inner edge of the guide plate 3 is integrally provided with the outer surface of the fixed shaft 8. The top end of the fixed shaft 8 is fixedly connected to the bottom of the main housing 1. The guide plate 3 is a spiral structure extending along the axial direction of the main housing 1. It can reduce natural convection between different water temperature layers, making the temperature stratification in the main housing 1 more obvious, and facilitating water extraction according to water temperature stratification. Therefore, it is adaptable to provide multiple heat release drain outlets 7 on both the main box body 1 and the auxiliary box body 2, and the multiple heat release drain outlets 7 are spaced apart up and down, so that it is convenient to take water of different water temperatures from different heat release drain outlets 7 according to heating needs.

[0050] In an exemplary embodiment, in order to further improve the heat storage capacity of the hot water storage tank, as shown in FIG. Figure 3 As shown, a plurality of phase-change heat storage tubes 9 are also provided in the main body 1 of the hot water storage tank. The phase-change heat storage tubes 9 extend axially along the main body 1 and are fixedly passed through the guide vanes 3. This allows the high-temperature water entering the main body 1 to flow through each layer and region of the main body 1 from top to bottom in the direction of flow set by the guide vanes 3 and exchange heat with the phase-change material inside. This prolongs the heat exchange time between the water and the phase-change material, making the heat exchange more complete, enhancing the heat exchange effect, and suppressing the existence of heat exchange dead zones. At the same time, the phase-change heat storage tubes 9 are fixedly passed through the guide vanes 3, eliminating the need for additional fixing measures for the phase-change heat storage tubes 9.

[0051] And, as Figure 6As shown, the phase-change heat storage tube 9 is arranged in a circuitous manner within the vertical plane. This increases the heat exchange area between the phase-change material and the water, improving heat exchange efficiency. The phase-change heat storage tube 9 is arranged in a circular array along the circumference of the main tank 1. The phase-change heat storage tube 9 is filled with a plurality of phase-change materials having different phase-change temperatures in layers. From bottom to top, the phase-change materials having different phase-change temperatures are filled in the phase-change heat storage tube 9 in layers according to the phase-change temperature from small to large. This effectively adapts to the temperature differences between the various layers of the water tank, enhances the utilization of the phase-change material, and makes its phase change more complete, thereby storing more heat.

[0052] In summary, the solar inter-seasonal heat storage system provided in the embodiments of the present application has the advantages of high heat storage efficiency and low heat loss.

[0053] Finally, it should be noted that the various technical features of the technical solution of this application can be combined arbitrarily. In order to make the description concise, not all possible combinations of the various technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0054] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and description of the present invention.

Claims

1. A solar inter-seasonal heat storage system, comprising a solar heat collection subsystem (100), an underground heat storage subsystem (200), and a heat supply subsystem (300), wherein the underground heat storage subsystem (200) comprises a heat storage tank buried underground, wherein the outer wall of the heat storage tank is coated with a heat insulation material, and wherein: The hot water storage tank comprises a columnar main tank body (1) and a sub-tank body (2) arranged at the bottom of the main tank body (1); the sub-tank body (2) is in an inverted cone structure, and the top of the sub-tank body (2) and the bottom of the main tank body (1) are connected through each other; the main tank body (1) has a guide plate (3) inside for reducing the water flow speed; The top of the main box (1) is provided with a heat storage water inlet (4) and an exhaust port (5), and the heat storage water inlet (4) is arranged opposite to the top of the guide plate (3); the heat storage water inlet (4) is connected to the solar heat collection subsystem (100) through a pipeline; A water outlet (6) is provided at the bottom end of the auxiliary box (2); the water outlet (6) is connected to the solar heat collection subsystem (100) through a pipeline; At least one heat release drain outlet (7) is provided on the main box body (1) and / or the auxiliary box body (2), and the heat release drain outlet (7) is connected to the heating subsystem (300) via a pipeline.

2. A solar inter-seasonal heat storage system according to claim 1, characterized in that: The auxiliary box (2) is an inverted cone structure.

3. The solar inter-seasonal heat storage system according to claim 1, characterized in that: The auxiliary box (2) is an inverted pyramid structure.

4. The solar inter-seasonal heat storage system according to claim 1, characterized in that: The cone bottom angle of the auxiliary box (2) is [40°, 70°].

5. The solar inter-seasonal heat storage system according to claim 1, characterized in that: The guide plate (3) is a spiral structure extending along the axial direction of the main box (1); the outer edge of the guide plate (3) is arranged in contact with the inner wall of the main box (1); the middle part of the guide plate (3) has a fixed shaft (8); the inner edge of the guide plate (3) is integrally arranged with the outer surface of the fixed shaft (8); the top end of the fixed shaft (8) is fixedly connected to the inner bottom of the main box (1).

6. The solar inter-seasonal heat storage system according to claim 5, characterized in that: A plurality of phase-change heat storage tubes (9) are provided in the heat storage tank. The phase-change heat storage tubes (9) are axially extending along the main body (1). The phase-change heat storage tubes (9) are fixedly inserted into the guide plate (3).

7. The solar inter-seasonal heat storage system according to claim 6, characterized in that: The phase change heat storage tube (9) is filled with a plurality of phase change materials with different phase change temperatures in layers; from bottom to top, the plurality of phase change materials with different phase change temperatures are sequentially filled in the phase change heat storage tube (9) in layers according to the phase change temperature from small to large.

8. The solar inter-seasonal heat storage system according to claim 6, characterized in that: The phase-change heat storage tube (9) is arranged to extend in a circuitous manner in a vertical plane.

9. The solar inter-seasonal heat storage system according to claim 1, characterized in that: The main box body (1) and the auxiliary box body (2) are both provided with a plurality of heat release drain ports (7), and the plurality of heat release drain ports (7) are arranged at intervals in the upper and lower parts.

10. The solar inter-seasonal heat storage system according to claim 1, characterized in that: The solar heat collecting subsystem (100) comprises a solar cooker (11), the solar cooker (11) being arranged on a light-chasing base (12), the water outlet (6) being connected to a heating cavity (13) arranged at a focus of the solar cooker (11) via a first pipe, and the first pipe being provided with a water pump and a valve; The heating cavity (13) is connected to the heat storage water inlet (4) via a second pipe, and a valve is provided on the second pipe.

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