PVT heat pump heating system and method integrating underground water storage and coupling phase change heat storage

Abstract

The invention provides a PVT heat pump heating system and method integrating underground water storage and coupling phase change heat storage, the PVT heat pump heating system comprises a solar photovoltaic photo-thermal assembly, an underground heat storage assembly, a heat pump and a heat consumer, the solar photovoltaic photo-thermal assembly is provided with a water supply inlet and a water supply outlet, and the water supply inlet is connected with an external water source; the water supply outlet is connected with the underground heat storage assembly and used for providing a heat source for the underground heat storage assembly. The solar photovoltaic photo-thermal assembly is further used for supplying power to the heat pump. The underground heat storage assembly is used for storing a heat source; the heat pump is used for heating a heat source in the underground heat storage assembly and conveying the heat source to a heat user. The underground heat storage assembly comprises an underground tank body and an underground water and heat storage pool, the underground water and heat storage pool is arranged in the underground tank body, and a phase change heat storage material is filled between the underground tank body and the underground water and heat storage pool; according to the system, through comprehensive utilization of various energy sources, dependence on high-cost energy sources is reduced, so that the overall operation cost of the heating system is reduced, and economic benefits are improved.

Description

Technical Field

[0001] The present invention belongs to the field of cogeneration, and relates to a PVT heat pump heating system and method integrating underground water storage coupled with phase change heat storage. Background Art

[0002] With the rapid development of the global economy and the continuous growth of population, the demand for energy continues to rise. The large-scale consumption of traditional fossil energy such as coal, oil and natural gas has not only led to the decreasing reserves, but also caused serious environmental problems, such as global warming and air pollution caused by greenhouse gas emissions. In the field of heating, especially in the winter in the cold northern regions, the demand for heating is huge, and the traditional coal-fired boiler heating method still occupies a large proportion, which has imposed a heavy burden on the environment. Therefore, it is imperative to develop clean, efficient and sustainable heating technology. Renewable energy, such as solar energy, wind energy, geothermal energy, etc., has become a key direction for solving energy and heating problems because of its pollution-free and renewable characteristics. Among them, solar energy, as a widely distributed and abundant clean energy, has attracted much attention for its application potential in the field of heating.

[0003] Solar energy is a clean energy source, but it is limited by weather and time, and its supply is discontinuous. The heating efficiency of the traditional single heat pump system will decrease in extreme weather (such as extremely cold weather), and the heat storage part in this system can supplement the heat at this time to ensure the normal heating of the system. The traditional electric heating or pure fossil fuel heating system has high energy consumption and high cost. Summary of the invention

[0004] The purpose of the present invention is to provide a PVT heat pump heating system and method that integrates underground water storage and coupled phase change thermal storage, which solves the defect that the heating efficiency of the existing traditional single heat pump system decreases in extreme weather.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is: The present invention provides a PVT heat pump heating system integrating underground water storage coupled with phase change heat storage, comprising a solar photovoltaic thermal component, an underground heat storage component, a heat pump and a heat user, wherein: The solar photovoltaic thermal component is provided with a water supply inlet and a water supply outlet, the water supply inlet is connected to an external water source; the water supply outlet is connected to an underground heat storage component for providing a heat source to the underground heat storage component; the solar photovoltaic thermal component is also used to supply power to a heat pump; The underground heat storage assembly is used to store heat source; the heat pump is used to heat the heat source in the underground heat storage assembly and transport it to the heat user; The underground heat storage assembly includes an underground tank body and an underground water heat storage tank, wherein the underground water heat storage tank is placed in the underground tank body, and a phase change heat storage material is filled between the two.

[0006] Preferably, the solar photovoltaic thermal assembly includes a photovoltaic panel, a heat collecting plate is installed on the back of the photovoltaic panel, a water supply inlet of the heat collecting plate is connected to an external water source, and a water supply outlet of the heat collecting plate is connected to an underground heat storage assembly.

[0007] Preferably, the heat collecting plate comprises a heat absorbing plate, the upper surface of which is mounted on the back of the photovoltaic panel, and the lower surface of which is arranged with a plurality of fluid channels interconnected with each other, wherein a water inlet and a water outlet are provided on the fluid channels. Preferably, the heat collecting plate includes a heat absorbing plate, the upper surface of which is mounted on the back of the photovoltaic panel, and the lower surface of which is arranged with two parallel first manifolds and second manifolds, and there are multiple fluid channels connected to each other between the first manifold and the second manifold, the water inlet of the fluid channel placed at the front is connected to an external water source through the first manifold, and the water outlet of the fluid channel placed at the rear is connected to an underground heat storage component through the second manifold; the axial direction of the fluid channel is perpendicular to the axial direction of the manifold.

[0008] Preferably, the heat pump comprises a compressor, a condenser, an expander and an evaporator, wherein the compressor is provided with a water supply inlet, which is connected to the water supply outlet of the underground heat storage component; the outlet of the compressor is connected to the evaporator through the condenser and the expansion valve in sequence, and the outlet of the evaporator is connected to the heat user.

[0009] Preferably, a bypass is provided between the water supply outlet of the underground heat storage component and the water supply inlet of the solar photovoltaic thermal component to heat and raise the temperature of the water supply with insufficient temperature.

[0010] Preferably, a bypass is provided between the return water outlet of the heat user and the water supply inlet of the solar photovoltaic thermal assembly to heat and increase the temperature of the return water.

[0011] A PVT heat pump heating method integrating underground water storage coupled with phase change heat storage comprises the following steps: In summer, the solar photovoltaic thermal module is used to heat the water supply, and the heated water supply is injected into the underground thermal storage module to exchange heat with the phase change material. The cooled water supply is pumped to the solar photovoltaic thermal module to continue heating until the phase change material in the underground thermal storage module reaches the heat absorption saturation state. In winter, when receiving heat demand from heat users, the water supply of the underground heat storage component is injected into the heat pump for reheating, and the heated water supply is delivered to the heat users.

[0012] Preferably, when the solar irradiance is greater than a threshold value, the return water of the heat user is transported to the solar photovoltaic thermal assembly to heat the return water.

[0013] Preferably, when the heated water supply is delivered to the heat user, the water supply temperature information and solar irradiance at the water supply outlet of the underground thermal storage assembly are obtained in real time, wherein: When the water supply temperature is less than a first preset value and the solar irradiance is greater than a threshold value, a portion of the water supply of the underground heat storage assembly is transported to the solar photovoltaic thermal assembly, and the water supply is heated by solar energy. The heated water supply is transported to the underground heat storage assembly and mixed with the remaining water supply in the underground heat storage assembly to increase the water supply temperature in the underground heat storage assembly.

[0014] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a PVT heat pump heating system that integrates underground water storage and coupled phase change heat storage. The application uses solar photovoltaic and thermal components to heat the water supply, and then stores the heat energy in the underground heat storage components. When it is necessary to heat the heat users, the stored heat energy is transmitted to the heat users. During this period, since the underground heat storage components are provided with phase change materials, when the heat energy of the underground heat storage components changes, the water supply is fine-tuned by releasing heat energy through the phase change materials to ensure the water supply temperature; then the water supply is reheated and heated using heat pump technology, which can effectively improve low-grade heat energy, and use less electric energy to raise the heat to a suitable temperature for heating, thereby reducing energy consumption. This system reduces dependence on high-cost energy through the comprehensive utilization of multiple energy sources, thereby reducing the overall operating cost of the heating system and improving economic benefits.

[0015] Furthermore, when the solar irradiance is greater than a preset threshold, the return water from the heat user side is transported to the solar photovoltaic thermal assembly for heating, which can effectively utilize low-grade thermal energy, thereby reducing the overall operating cost of the heating system and improving economic benefits.

[0016] The present invention provides a PVT heat pump heating method that integrates underground water storage and coupled phase change heat storage. The method uses solar photovoltaic and thermal components to heat the water supply, and then stores the heat energy in the underground heat storage components. When it is necessary to heat the heat users, the stored heat energy is reheated and heated using heat pump technology, which can effectively improve low-grade heat energy, use less electric energy to raise the heat to a suitable temperature for heating, and reduce energy consumption. This system reduces dependence on high-cost energy through the comprehensive utilization of multiple energy sources, thereby reducing the overall operating cost of the heating system and improving economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of a flow chart of an embodiment of the present invention. DETAILED DESCRIPTION

[0018] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0019] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, wholes, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or combinations thereof.

[0020] It should also be understood that the term “and / or” used in the specification and appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0021] As used in the specification and appended claims of this application, the term "if" can be interpreted as "when" or "uponce" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrase "if it is determined" or "if [described condition or event] is detected" can be interpreted as meaning "uponce it is determined" or "in response to determining" or "uponce [described condition or event] is detected" or "in response to detecting [described condition or event]", depending on the context.

[0022] In addition, in the description of the present application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0023] References to "one embodiment" or "some embodiments" etc. described in the specification of this application mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the statements "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0024] Example 1 like Figure 1As shown, this embodiment provides a PVT heat pump heating system integrating underground water storage coupled with phase change thermal storage, including a solar photovoltaic thermal component 1, an underground thermal storage component 2, a heat pump 3 and a heat user 4, wherein: The solar photovoltaic thermal component 1 is provided with a water supply inlet and a water supply outlet, the water supply inlet is connected to an external water source; the water supply outlet is connected to an underground heat storage component, and is used to provide a heat source to the underground heat storage component; the solar photovoltaic thermal component is also used to supply power to a heat pump; The underground heat storage assembly 2 is used to store heat source; The heat pump 3 is used to heat the heat source in the underground heat storage assembly and transmit it to the heat user.

[0025] Among them, solar photovoltaic thermal components (PVT) are a new energy utilization technology that organically combines solar photovoltaic (PV) technology with solar thermal (Thermal) technology. Photovoltaic technology directly converts solar energy into electrical energy through the photoelectric effect of semiconductor materials, while thermal technology uses the thermal energy of solar energy to heat working fluids such as air, water or other heat-conducting media. PVT components can simultaneously realize photoelectric conversion and thermal utilization on the same area, improving the comprehensive utilization efficiency of solar energy. Compared with a single PV system, a PVT system can not only generate electricity, but also recycle the heat generated by photovoltaic cells and reduce the temperature of the cells, thereby improving the power generation efficiency and service life of photovoltaic cells. For example, in some practical applications, the PVT system can reduce the temperature of photovoltaic cells by 10-20℃ and increase the power generation efficiency by 5%-15%. However, PVT technology also faces some challenges. Due to the intermittent and unstable nature of solar energy, the output of electricity and heat generated by the PVT system is unstable, making it difficult to directly meet the user's continuous and stable heating needs. In addition, during periods without solar radiation, such as cloudy days and nights, the energy supply of the PVT system is almost interrupted, and an effective energy storage system is needed to make up for the gap in energy supply.

[0026] Heat pump technology is an efficient heat energy utilization technology based on the reverse Carnot cycle principle, which can upgrade low-grade heat energy to high-grade heat energy. Heat pumps absorb heat from low-temperature heat sources (such as air, water, soil, etc.) by consuming a small amount of electricity or other high-grade energy, and transfer the heat to high-temperature heat sources through a series of processes such as compression, condensation, expansion, and evaporation to achieve functions such as heating, cooling, or hot water supply. In heating applications, heat pumps have significant energy-saving advantages, and their energy efficiency ratio (COP) is usually between 2 and 5, that is, consuming 1 unit of electricity can generate 2 to 5 units of heat energy. Compared with traditional electric heating methods, the energy saving effect can reach 50% to 80%.

[0027] Underground thermal storage components are a way of storing heat in groundwater or aquifers by utilizing the good thermal properties and large thermal capacity of underground rock and soil. Underground rock and soil have the characteristics of relatively stable temperature and small thermal diffusion coefficient, making them suitable as thermal storage media.

[0028] Example 2 Based on Example 1, this example provides a PVT heat pump heating system that integrates underground water storage and phase change heat storage, wherein the underground heat storage component 2 includes an underground tank body 22 and an underground water heat storage tank 21, wherein the underground water heat storage tank is placed in the underground tank body, and phase change heat storage material is filled between the two.

[0029] Example 3 Based on Example 1, this example provides a PVT heat pump heating system that integrates underground water storage and phase change heat storage, wherein the solar photovoltaic thermal component includes a photovoltaic panel, a thermal collector is installed on the back of the photovoltaic panel, a water supply inlet of the thermal collector is connected to an external water source, and a water supply outlet of the thermal collector is connected to an underground heat storage component.

[0030] The heat collecting plate comprises a heat absorbing plate, the upper surface of which is mounted on the back of the photovoltaic panel, and the lower surface of which is arranged with a plurality of fluid channels interconnected with each other, wherein the fluid channels are provided with a water inlet and a water outlet for the entry and exit of the heat transfer fluid.

[0031] Example 4 On the basis of Example 3, this embodiment provides a PVT heat pump heating system integrating underground water storage and coupled phase change heat storage, wherein the heat collecting plate includes a heat absorbing plate, the upper surface of the heat absorbing plate is installed on the back of the photovoltaic panel, and the lower surface of the heat absorbing plate is arranged with two parallel arranged first manifolds and second manifolds, and there are multiple fluid channels connected to each other between the first manifold and the second manifold, the water inlet of the fluid channel placed at the front is connected to an external water source through the first manifold, and the water outlet of the fluid channel placed at the rear is connected to the underground heat storage component through the second manifold.

[0032] The axial direction of the fluid channel is perpendicular to the axial direction of the header.

[0033] Example 5 Based on Example 1, this example provides a PVT heat pump heating system that integrates underground water storage and phase change thermal storage, wherein the heat pump includes a compressor, a condenser, an expander and an evaporator, wherein a water supply inlet is provided on the compressor, and the water supply inlet is connected to the water supply outlet of the underground thermal storage component; the outlet of the compressor is connected to the evaporator through the condenser and the expansion valve in turn, and the outlet of the evaporator is connected to a heat user.

[0034] Example 6 Based on Example 1, this example provides a PVT heat pump heating system that integrates underground water storage and phase change thermal storage, wherein a bypass is provided between the water supply outlet of the underground thermal storage component and the water supply inlet of the solar photovoltaic thermal component to heat and raise the temperature of the water supply that is insufficient in temperature.

[0035] Example 7 Based on Example 1, this example provides a PVT heat pump heating system that integrates underground water storage and phase change thermal storage, wherein a bypass is provided between the heat user return water outlet and the water supply inlet of the solar photovoltaic thermal component to heat the return water.

[0036] Example 7 On the basis of Example 1, this example provides a PVT heat pump heating system integrating underground water storage coupled with phase change thermal storage, wherein a first solenoid valve is provided on the connecting pipe between the water supply inlet and the external water source.

[0037] A second solenoid valve is provided on the connecting pipe between the water supply outlet and the underground heat storage assembly.

[0038] A third solenoid valve is provided on the connecting pipe between the water supply outlet of the underground heat storage component and the heat user.

[0039] A fourth solenoid valve is provided on the connecting pipe between the water supply outlet of the underground heat storage component and the water supply inlet of the solar photovoltaic thermal component.

[0040] The first valve, the second valve, the third valve and the fourth valve are all connected to a control system.

[0041] The control system is also connected to a data acquisition unit, which is used to obtain the solar irradiance and the water supply temperature at the water supply outlet of the underground thermal storage component.

[0042] The control system is used to control the start and stop of the valve according to the acquired solar irradiance and the water supply temperature at the water supply outlet of the underground thermal storage component.

[0043] Example 8 The present embodiment provides a PVT heat pump heating method integrating underground water storage coupled with phase change thermal storage, comprising the following steps: In summer, the solar photovoltaic thermal module is used to heat the water supply, and the heated water supply is injected into the underground thermal storage module to exchange heat with the phase change material. The cooled water supply is pumped to the solar photovoltaic thermal module to continue heating until the phase change material in the underground thermal storage module reaches the heat absorption saturation state. In winter, when receiving heat demand from heat users, the first solenoid valve, the second solenoid valve and the third solenoid valve are opened, and the fourth solenoid valve is closed. The water supply of the underground heat storage component is injected into the heat pump for reheating. The heated water supply is transported to the heat users, and the return water of the heat users is transported to the solar photovoltaic thermal component to heat the return water.

[0044] When the heated water supply is delivered to the heat user, the water supply temperature information and solar irradiance at the water supply outlet of the underground thermal storage component are obtained in real time, where: When the water supply temperature is less than the first preset value and the solar irradiance is greater than the threshold value, the fourth solenoid valve is opened to deliver part of the water supply of the underground heat storage assembly to the solar photovoltaic thermal assembly, and the water supply is heated by solar energy. The heated water supply is delivered to the underground heat storage assembly and mixed with the remaining water supply in the underground heat storage assembly to increase the water supply temperature in the underground heat storage assembly.

[0045] In this embodiment, when the water supply temperature in the underground heat storage component is insufficient and the solar irradiance meets the threshold requirement, part of the water supply is heated and heated by solar energy, and then mixed with the remaining water supply to increase the water supply temperature in the underground heat storage component; this embodiment can effectively solve the problem of seasonal imbalance in energy supply and improve energy utilization efficiency. For example, some ground source heat pump systems combine underground water storage and heat storage technology to transfer heat in buildings to underground storage in summer, and reuse the stored heat to heat buildings in winter, realizing comprehensive energy utilization throughout the year. Phase change thermal storage technology is a heat storage method that uses the characteristics of phase change materials to absorb or release a large amount of latent heat during the phase change process to store and release heat. Phase change materials undergo phase changes within a specific temperature range, such as from solid to liquid or from liquid to gas. In this process, phase change materials can absorb or release a large amount of heat, while their own temperature changes very little. Common phase change materials include inorganic hydrated salts, organic paraffins, fatty acids, etc. Phase change thermal storage technology has the advantages of high thermal storage density and small temperature fluctuation during the heat storage and heat release process. It can effectively solve the intermittent problem of energy supply and improve the stability of energy supply.

[0046] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such 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 application, and should all be included in the protection scope of the present application.

Claims

1. A PVT heat pump heating system integrating underground water storage and phase change thermal storage, characterized in that: Including solar photovoltaic and thermal components, underground thermal storage components, heat pumps and heat users, including: The solar photovoltaic thermal component is provided with a water supply inlet and a water supply outlet, the water supply inlet is connected to an external water source; the water supply outlet is connected to an underground heat storage component for providing a heat source to the underground heat storage component; the solar photovoltaic thermal component is also used to supply power to a heat pump; The underground heat storage assembly is used to store heat source; the heat pump is used to heat the heat source in the underground heat storage assembly and transport it to the heat user; The underground heat storage assembly includes an underground tank body and an underground water heat storage tank, wherein the underground water heat storage tank is placed in the underground tank body, and a phase change heat storage material is filled between the two.

2. A PVT heat pump heating system integrating underground water storage and phase change thermal storage according to claim 1, characterized in that: The solar photovoltaic thermal assembly includes a photovoltaic cell panel, a heat collecting plate is installed on the back of the photovoltaic cell panel, a water supply inlet of the heat collecting plate is connected to an external water source, and a water supply outlet of the heat collecting plate is connected to an underground heat storage assembly.

3. A PVT heat pump heating system integrating underground water storage and phase change thermal storage according to claim 2, characterized in that: The heat collecting plate comprises a heat absorbing plate, the upper surface of which is mounted on the back of the photovoltaic cell panel, and the lower surface of which is arranged with a plurality of fluid channels connected to each other, wherein the fluid channels are provided with a water inlet and a water outlet.

4. A PVT heat pump heating system integrating underground water storage and phase change thermal storage according to claim 2, characterized in that: The heat collecting plate comprises a heat absorbing plate, the upper surface of which is mounted on the back of the photovoltaic cell panel, and the lower surface of which is arranged with two first and second parallel headers, and a plurality of fluid channels connected to each other are arranged between the first and second headers, the water inlet of the fluid channel at the head is connected to an external water source through the first header, and the water outlet of the fluid channel at the tail is connected to an underground heat storage component through the second header; the axial direction of the fluid channel is perpendicular to the axial direction of the header.

5. The PVT heat pump heating system integrating underground water storage and phase change thermal storage according to claim 1 is characterized in that: The heat pump includes a compressor, a condenser, an expander and an evaporator, wherein the compressor is provided with a water supply inlet, which is connected to the water supply outlet of the underground heat storage component; the outlet of the compressor is connected to the evaporator through the condenser and the expansion valve in sequence, and the outlet of the evaporator is connected to the heat user.

6. A PVT heat pump heating system integrating underground water storage and phase change thermal storage according to claim 1, characterized in that: A bypass is provided between the water supply outlet of the underground heat storage component and the water supply inlet of the solar photovoltaic thermal component to heat and raise the temperature of the water supply with insufficient temperature.

7. The PVT heat pump heating system integrating underground water storage and phase change thermal storage according to claim 1 is characterized in that: A bypass is provided between the return water outlet of the heat user and the water supply inlet of the solar photovoltaic thermal component to heat and increase the temperature of the return water.

8. A PVT heat pump heating method integrating underground water storage coupled with phase change thermal storage, characterized in that: The following steps are involved: In summer, the solar photovoltaic thermal module is used to heat the water supply, and the heated water supply is injected into the underground thermal storage module to exchange heat with the phase change material. The cooled water supply is pumped to the solar photovoltaic thermal module to continue heating until the phase change material in the underground thermal storage module reaches the heat absorption saturation state. In winter, when receiving heat demand from heat users, the water supply of the underground heat storage component is injected into the heat pump for reheating, and the heated water supply is delivered to the heat users.

9. A PVT heat pump heating method integrating underground water storage coupled with phase change thermal storage according to claim 8, characterized in that: When the solar irradiance is greater than the threshold, the return water from the heat user is transported to the solar photovoltaic thermal assembly to heat the return water.

10. A PVT heat pump heating method integrating underground water storage coupled with phase change thermal storage according to claim 8, characterized in that: When the heated water supply is delivered to the heat user, the water supply temperature information and solar irradiance at the water supply outlet of the underground thermal storage component are obtained in real time, where: When the water supply temperature is less than a first preset value and the solar irradiance is greater than a threshold value, a portion of the water supply of the underground heat storage assembly is transported to the solar photovoltaic thermal assembly, and the water supply is heated by solar energy. The heated water supply is transported to the underground heat storage assembly and mixed with the remaining water supply in the underground heat storage assembly to increase the water supply temperature in the underground heat storage assembly.

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