Middle-deep geothermal-photovoltaic photo-thermal coupling cross-seasonal composite energy storage system and method

Abstract

The invention relates to the technical field of composite energy storage, in particular to a mid-deep layer geothermal-photovoltaic photo-thermal coupling cross-seasonal composite energy storage system and a mid-deep layer geothermal-photovoltaic photo-thermal coupling cross-seasonal composite energy storage method. Comprising an energy storage system and a circulating system which are connected. The energy storage system comprises a photovoltaic photo-thermal plate and a middle-deep layer ground source, wherein the photovoltaic photo-thermal plate is connected with the middle-deep layer ground source through a photovoltaic heat exchange pipeline. The photovoltaic photo-thermal plate can convey unutilized heat energy to a middle-deep layer ground source through the photovoltaic heat exchange pipeline, and the heating problem of the photovoltaic photo-thermal plate is relieved by utilizing the characteristic that the rock-soil layer can bear intermittent heat input; and heat attenuation caused by long-term heat extraction of the rock-soil body can be relieved through the heat energy guided into the middle-deep layer ground source, and the utilization efficiency of the middle-deep layer ground source is improved.

Description

Technical Field

[0001] The present invention relates to the field of composite energy storage technology, and in particular to a mid-deep geothermal-photovoltaic thermal coupling cross-seasonal composite energy storage system and method. Background Art

[0002] As a widely used type of integrated energy system, the gas-fired combined heat, cooling and power system converts natural gas into electricity through a gas turbine using carbon-based primary energy such as natural gas, and further provides heat and cooling using the waste heat resources generated during the power generation process, thus achieving multi-level utilization and efficient conversion of energy. However, due to the significant seasonal peak-to-valley differences in my country's natural gas consumption market, the demand for natural gas has increased significantly due to the surge in heating demand in winter, while it has decreased relatively in summer. This seasonal fluctuation has brought tremendous pressure on the supply of natural gas. In addition, my country's natural gas supply relies on imports at a foreign dependence rate of nearly 40%, indicating that the stable supply of the domestic natural gas market is greatly affected by fluctuations in gas supply from foreign gas source countries, increasing the uncertainty of energy security. Therefore, new energy supply technologies are urgently needed.

[0003] As an alternative to the above energy supply technologies, solar energy is a renewable energy source that is widely distributed and environmentally friendly. However, its inherent intermittent, volatile and unpredictable characteristics make it difficult for the energy system to achieve stable operation. In addition, in actual use, the energy utilization rate of photovoltaic thermal panels is low, and the unused energy is converted into heat energy, which damages the structure of the photovoltaic panels and affects the photoelectric conversion efficiency. Another energy supply technology is geothermal energy, which has the characteristics of stable energy supply, large reserves and wide distribution, but there will be problems of thermal attenuation after a long period of use.

[0004] In addition, the energy stored in existing energy storage structures or systems needs to be processed by various conversion devices when used to form corresponding energy that can be directly applied. However, this conversion process will inevitably produce energy loss and is accompanied by disadvantages such as reduced efficiency, which affects the overall energy utilization efficiency. Summary of the invention

[0005] In response to the problems mentioned in the prior art, the present invention proposes a mid-deep geothermal-photovoltaic thermal coupling cross-seasonal composite energy storage system and method, which solves the problems in the background technology of reduced power generation efficiency of photovoltaic thermal panels due to thermal energy, alleviation of thermal attenuation caused by long-term heating of rock and soil, and energy loss caused by corresponding energy use.

[0006] In order to achieve the above object, the present invention adopts the following technical solution: The present invention discloses a mid-deep geothermal-photovoltaic thermal coupling cross-seasonal composite energy storage system, comprising a connected energy storage system and a circulation system; the energy storage system comprises photovoltaic thermal panels and mid-deep geothermal sources, wherein the photovoltaic thermal panels are connected to the mid-deep geothermal sources via photovoltaic heat exchange pipes; the circulation system comprises a delivery pipeline, a cold and hot dual heat pump unit, an energy storage tank and a working fluid box, the delivery pipeline is arranged in the mid-deep geothermal source, one end of the delivery pipeline is connected to the cold and hot dual heat pump unit, and the other end of the cold and hot dual heat pump unit is respectively connected to the energy storage tank and the working fluid box.

[0007] As a further improvement of the present invention, the photovoltaic thermal panel is connected to the input port of the photovoltaic heat exchange pipeline, and the output port of the photovoltaic heat exchange pipeline is deep underground to the medium-deep ground source for heat exchange.

[0008] As a further improvement of the present invention, the input port and the output port of the delivery pipeline are both connected to the first input port of the dual-heat and cold heat pump unit, wherein the second input port of the dual-heat and cold heat pump unit is connected to the working fluid box, and the output port of the dual-heat and cold heat pump unit is connected to the energy storage tank through a connecting pipe.

[0009] As a further improvement of the present invention, the energy storage tank includes a heat storage tank and a cold storage tank, wherein the phase change materials in the heat storage tank and the cold storage tank are different.

[0010] As a further improvement of the present invention, the phase change material is arranged in the energy storage rod, and a plurality of energy storage rods are arranged in the energy storage tank.

[0011] As a further improvement of the present invention, a valve and a circulation pump are sequentially provided on the communicating pipeline.

[0012] As a further improvement of the present invention, the conveying pipeline is a sleeve or a U-shaped pipe.

[0013] A method for a mid-deep geothermal-photovoltaic thermal coupling cross-seasonal composite energy storage system, comprising the following steps: The photovoltaic heat exchange pipeline introduces the excess heat energy from the photovoltaic thermal panels into the medium-deep ground source. The heat exchange medium flows through the transmission pipeline installed in the medium-deep ground source and is transported to the dual-heat heat pump unit. After being processed by the dual-heat heat pump unit, it is transported to the energy storage tank.

[0014] As a further improvement of the present invention, the photovoltaic heat exchange pipeline guides the heat energy converted from the unused solar energy on the photovoltaic thermal panels into the mid-deep ground source.

[0015] As a further improvement of the present invention, the dual-heat and cold-heat pump unit transports the working fluid to the medium-deep ground source through a transport pipeline and then returns. The working fluid after heat exchange is processed by the dual-heat and cold-heat pump unit and transported to a heat storage tank or a cold storage tank as needed.

[0016] Compared with the prior art, the present invention has achieved the following technical effects: The photovoltaic thermal panels in the present invention can transport unused heat energy to medium and deep ground sources through photovoltaic heat exchange pipes, solving the problem that unused heat energy may cause the temperature of the thermal panel surface to rise, causing damage to the panel surface and affecting the power generation efficiency of the photovoltaic thermal panels; the photovoltaic heat exchange pipes introduce unused heat energy into medium and deep ground sources, and utilize the characteristic that the rock and soil layer can carry intermittent heat input to alleviate the heating problem of the photovoltaic thermal panels. In addition, the heat energy introduced into the medium and deep ground sources can alleviate the thermal attenuation caused by long-term heating of the rock and soil body and improve the utilization efficiency of medium and deep geothermal energy.

[0017] The energy storage tank in the present invention is divided into a heat storage tank and a cold storage tank. The two types of energy storage tanks can be used in different seasons according to needs, thereby improving the flexibility and utilization efficiency of energy. The phase change material in the heat storage tank will undergo phase change after absorbing heat, thereby storing a large amount of thermal energy. It can be used directly in winter or in situations where additional heat is required without the need for a conversion device, which can effectively improve energy utilization efficiency and reduce dependence on traditional heating methods. On the contrary, the cold storage tank uses a material that can undergo phase change when releasing cold energy. In summer or in situations where cooling is required, the cold storage tank can release the stored cold energy without the need for a conversion device, thereby also achieving efficient utilization of energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the deep geothermal-photovoltaic thermal coupling cross-seasonal composite energy storage system of the present invention operating in the first operating mode; Figure 2 It is a schematic diagram of the deep geothermal-photovoltaic thermal coupling cross-seasonal composite energy storage system of the present invention operating in the second operation mode; Figure 3 It is a schematic diagram of the deep geothermal-photovoltaic thermal coupling cross-seasonal composite energy storage system of the present invention operating in the third operation mode; Figure 4 It is a schematic diagram of the packaging and fixing form of the phase change material in the deep geothermal-photovoltaic thermal coupling cross-seasonal composite energy storage system of the present invention.

[0019] Figure numerals: 1. Photovoltaic thermal panel; 2. Photovoltaic heat exchange pipeline; 3. Transportation pipeline; 4. Cold and hot dual heat pump unit; 5. Energy storage tank; 6. Working fluid box; 7. Valve; 8. Circulation pump. DETAILED DESCRIPTION

[0020] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0021] In the description of the present invention, 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 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 referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0022] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0023] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like 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, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0024] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0025] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0026] It should also be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0027] It should be further understood that the term "and / or" used in the present description and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0028] Various structural schematic diagrams of the embodiments disclosed in the present invention are shown in the accompanying drawings. These figures are not drawn to scale, and some details are magnified and some details may be omitted for the purpose of clear expression. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0029] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0030] Example 1 The present invention discloses a mid-deep geothermal-photovoltaic thermal coupling cross-seasonal composite energy storage system, comprising a connected energy storage system and a circulation system; the energy storage system comprises a photovoltaic thermal panel 1 and a mid-deep geothermal source, wherein the photovoltaic thermal panel 1 is connected to the mid-deep geothermal source via a photovoltaic heat exchange pipe 2; the circulation system comprises a delivery pipe 3, a hot and cold dual heat pump unit 4, an energy storage tank 5 and a working fluid box 6, wherein the delivery pipe 3 is arranged in the mid-deep geothermal source, one end of the delivery pipe 3 is connected to the hot and cold dual heat pump unit 4, and the other end of the hot and cold dual heat pump unit 4 is respectively connected to the energy storage tank 5 and the working fluid box 6.

[0031] The photovoltaic thermal panel 1 is connected to the input port of the photovoltaic heat exchange pipe 2, and the output port of the photovoltaic heat exchange pipe 2 is deep underground to the medium-deep ground source for heat exchange. Figure 1As shown, the photovoltaic thermal panel 1 in the embodiment is a device that can convert solar energy into heat energy and electrical energy. The device is a common existing technology, so it is not elaborated here. During the operation of the traditional photovoltaic thermal panel 1, the heat energy generated by the unused solar energy will cause the panel surface temperature to rise, affecting the efficiency of thermal power generation, and will cause permanent structural damage to the panel surface in the long run. Therefore, the present invention connects the photovoltaic thermal panel 1 with the photovoltaic heat exchange pipe 2, and the other end of the photovoltaic heat exchange pipe 2 is connected to the medium-deep ground source. In this way, the unused heat energy can be converted to the medium-deep ground source through the heat exchange medium. On the one hand, the panel surface temperature of the photovoltaic thermal panel 1 is always at a suitable temperature to prevent excessive temperature from affecting the efficiency of thermal power generation. On the other hand, the excess heat energy of the photovoltaic thermal panel 1 can be transported to the medium-deep ground source to alleviate the heat exhaustion phenomenon.

[0032] In the embodiment, the photovoltaic heat exchange pipe 2 can transfer the heat energy generated by the photovoltaic thermal panel 1 to the deep underground source for heat exchange. In order to ensure the heat conduction efficiency and corrosion resistance, the photovoltaic heat exchange pipe 2 is preferably made of a material with good thermal conductivity such as copper or aluminum. Figure 1 The photovoltaic heat exchange pipeline 2 is vertically arranged to ensure the effective transmission of heat energy. At the same time, the photovoltaic heat exchange pipeline 2 adopts a fully closed circulation mode. The heat exchange medium absorbs heat from the photovoltaic thermal panel 1 and is transmitted to the medium and deep ground source and then circulated back to the photovoltaic thermal panel 1.

[0033] The medium-deep ground source in this embodiment refers to geothermal water or strata located underground. When heat energy is exchanged with geothermal water or strata, the generated heat will be stored.

[0034] like Figure 2 It is a schematic diagram of the energy storage system, in which the input port and the output port of the delivery pipeline 3 are both connected to the first input port of the cold and hot dual heat pump unit 4, wherein the second input port of the cold and hot dual heat pump unit 4 is connected to the working fluid box 6, and the output port of the cold and hot dual heat pump unit 4 is connected to the energy storage tank 5 through a connecting pipe. In the embodiment, the delivery pipeline 3 is arranged in the medium-deep ground source, and the delivery pipeline 3 is a circulation loop design, and a circulating working fluid flows in the delivery pipeline 3, wherein the input port can deliver heat energy to the heat pump unit for processing, and the output port is used to inject the medium processed by the cold and hot dual heat pump unit 4 back into the medium-deep ground source to realize the recycling of energy; the delivery pipeline 3 is preferably a casing or a U-shaped pipe, which can better circulate the circulating working fluid.

[0035] In the embodiment, the dual-mode heat pump unit 4 can be used to convert thermal energy into usable thermal energy or cold energy. The dual-mode heat pump unit 4 is a common existing technology, so it will not be elaborated here; the first input port of the dual-mode heat pump unit 4 is used to receive thermal energy from the delivery pipeline 3, and the second input port is connected to the working fluid box 6. The working fluid box 6 is used to store the circulating working fluid of the energy storage system. When necessary, additional circulating working fluid can be introduced to supplement or adjust the temperature of the circulating working fluid. The circulating working fluid in this embodiment is preferably water, but it is not limited to this. Other circulating working fluids can be selected according to actual needs or usage scenarios; the output port can transport the heat energy or cold energy converted by the dual-mode heat pump unit 4 to the energy storage tank 5 for storage.

[0036] The energy storage tank 5 includes a heat storage tank and a cold storage tank, wherein the phase change materials in the heat storage tank and the cold storage tank are different. The phase change material is arranged in the energy storage rod, and the energy storage tank 5 is arranged with a plurality of energy storage rods. Figure 2 and Figure 4 As shown, the energy storage tank 5 in the embodiment consists of two, namely a heat storage tank and a cold storage tank. The heat storage tank is used to store the heat energy output by the dual-cooling and hot heat pump unit 4, and the cold storage tank is used to store the cold energy output by the dual-cooling and hot heat pump unit 4.

[0037] Figure 4 The upper middle figure is a cross-sectional view of the energy storage tank, and the lower figure is a top view of the energy storage tank. This embodiment takes a heat storage tank as an example. A plurality of energy storage rods are provided in the heat storage tank, and phase change material is used as a filling material for the energy storage rods. In the embodiment, the material of the inner part of the energy storage rod that contacts the phase change material adopts a material that does not react with the phase change material to ensure the stability and safety of the system, while the outer part adopts stainless steel material, which has good corrosion resistance and thermal conductivity and can meet the needs of long-term use; in addition, the energy storage rod can be connected to the top and bottom of the energy storage tank 5, thereby forming a complete heat conduction path, which helps to efficiently transfer the heat in the phase change material and realize energy storage and release.

[0038] The connecting pipe is provided with a valve 7 and a circulating pump 8 in sequence. Figure 2 or Figure 3 As shown, the connecting pipeline is designed as a circulation loop, and one of the loops in the connecting pipeline is provided with a valve 7 at one end close to the dual-cooling and heating heat pump unit 4, and a circulation pump 8 at the other end.

[0039] The valve 7 is used to control the flow of the circulating medium to start, stop or switch the energy storage system. In the embodiment, the valve 7 is preferably a solenoid valve or a pneumatic valve; the circulating pump 8 is used to provide power so that the circulating medium can overcome the pipeline resistance and flow continuously in the connecting pipeline.

[0040] The method of the present invention has three different operating modes. The operating mode of this embodiment is that the photovoltaic heat exchange pipeline 2 introduces the excess heat energy on the photovoltaic thermal panel 1 into the medium-deep ground source, and the circulating working fluid flows through the transmission pipeline 3 arranged in the medium-deep ground source and is transported to the hot and cold dual heat pump unit 4, and is transported to the energy storage tank 5 after being processed by the hot and cold dual heat pump unit 4.

[0041] Example 2 This embodiment is basically the same as the embodiment 1, except that this embodiment provides another operation mode, and the operation mode of this embodiment is specifically that the photovoltaic heat exchange pipe 2 introduces the heat energy converted from the unused solar energy on the photovoltaic thermal panel 1 into the medium-deep ground source. The rock and soil layer can carry the characteristics of intermittent heat input to alleviate the heating problem of the photovoltaic thermal panel 1, and the heat energy introduced into the medium-deep ground source can alleviate the thermal attenuation caused by the long-term heating of the rock and soil body and improve the utilization efficiency of the medium-deep geothermal energy.

[0042] Example 3 This embodiment is basically the same as Embodiment 1 and Embodiment 2, except that this embodiment provides another operating mode. The specific operating mode of this embodiment is that the dual-cooling and heat pump unit 4 transports the circulating working fluid to the medium-deep ground source through the delivery pipeline 3 and then returns. The circulating working fluid after heat exchange is processed by the dual-cooling and heat pump unit 4 and transported to the heat storage tank or the cold storage tank as needed.

[0043] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the attached claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any figure mark in the claims should not be regarded as limiting the claims involved.

[0044] In addition, it should be understood that although this specification is described in accordance with the implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation modes that can be understood by those skilled in the art. The above content is only to illustrate the technical idea of ​​the present invention, and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution according to the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A mid-deep geothermal-photovoltaic thermal coupling cross-seasonal composite energy storage system, characterized in that: Including connected energy storage system and circulation system; The energy storage system comprises a photovoltaic thermal panel and a medium-deep ground source, wherein the photovoltaic thermal panel and the medium-deep ground source are connected via a photovoltaic heat exchange pipeline; The circulation system includes a delivery pipeline, a dual-heat and cold heat pump unit, an energy storage tank and a working fluid box. The delivery pipeline is arranged in a medium-deep ground source. One end of the delivery pipeline is connected to the dual-heat and cold heat pump unit, and the other end of the dual-heat and cold heat pump unit is connected to the energy storage tank and the working fluid box respectively.

2. According to claim 1, a mid-deep geothermal-photovoltaic thermal coupling cross-seasonal composite energy storage system is characterized in that: The photovoltaic thermal panel is connected to the input port of the photovoltaic heat exchange pipeline, and the output port of the photovoltaic heat exchange pipeline is deep underground to the medium-deep ground source for heat exchange.

3. According to claim 1, a mid-deep geothermal-photovoltaic thermal coupling cross-seasonal composite energy storage system is characterized in that: The input port and output port of the delivery pipeline are both connected to the first input port of the dual-heat and cold heat pump unit, wherein the second input port of the dual-heat and cold heat pump unit is connected to the working fluid box, and the output port of the dual-heat and cold heat pump unit is connected to the energy storage tank through a connecting pipeline.

4. According to claim 3, a mid-deep geothermal-photovoltaic thermal coupling cross-seasonal composite energy storage system is characterized in that: The energy storage tank comprises a heat storage tank and a cold storage tank, wherein the phase change materials in the heat storage tank and the cold storage tank are different.

5. According to claim 4, a mid-deep geothermal-photovoltaic thermal coupling cross-seasonal composite energy storage system is characterized in that: The phase change material is arranged in the energy storage rod, and a plurality of energy storage rods are arranged in the energy storage tank.

6. According to claim 3, a mid-deep geothermal-photovoltaic thermal coupling cross-seasonal composite energy storage system is characterized in that: The communicating pipeline is provided with a valve and a circulating pump in sequence.

7. According to claim 3, a mid-deep geothermal-photovoltaic thermal coupling cross-seasonal composite energy storage system is characterized in that: The conveying pipeline is a casing or a U-shaped pipe.

8. A method for a mid-deep geothermal-photovoltaic thermal coupling cross-seasonal composite energy storage system according to any one of claims 1 to 7, characterized in that: The following steps are involved: The photovoltaic heat exchange pipeline introduces the excess heat energy from the photovoltaic thermal panels into the medium-deep ground source. The heat exchange medium flows through the transmission pipeline installed in the medium-deep ground source and is transported to the dual-heat heat pump unit. After being processed by the dual-heat heat pump unit, it is transported to the energy storage tank.

9. The method of the mid-deep geothermal-photovoltaic thermal coupling cross-seasonal composite energy storage system according to claim 8 is characterized in that: Photovoltaic heat exchange pipelines direct the heat energy converted from unused solar energy on photovoltaic thermal panels into medium and deep ground sources.

10. The method of the mid-deep geothermal-photovoltaic thermal coupling cross-seasonal composite energy storage system according to claim 8, characterized in that: The hot and cold dual heat pump unit transports the working fluid to the medium-deep ground source through a transmission pipeline and then returns. The working fluid after heat exchange is processed by the hot and cold dual heat pump unit and transported to the heat storage tank or cold storage tank as needed.

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