Photovoltaic photo-thermal system and intelligent agricultural greenhouse

Abstract

The invention provides a photovoltaic photo-thermal system. The photovoltaic photo-thermal system comprises a photovoltaic module (1); the heat storage device (9) is used for accommodating a liquid medium for storing heat; a heat sink (28); the photovoltaic module (1), the heat storage device (9) and the radiator (28) are arranged in the heat storage device (9), the photovoltaic module (1), the heat storage device (9) and the radiator (28) are arranged in the refrigerant loop (2), and a refrigerant in the refrigerant loop can exchange heat with the photovoltaic module (1), the heat storage device (9) and the radiator (28); wherein the refrigerant loop (2) is configured to enable the refrigerant passing through the photovoltaic module (1) to switch geothermal heat exchange between the heat storage device (9) and the radiator (28), in addition, the invention further provides an intelligent agricultural greenhouse comprising the photovoltaic and photo-thermal system, the working temperature of the photovoltaic module is reduced, the power generation efficiency of the photovoltaic module is improved, and the energy consumption of the photovoltaic module is reduced. Operation stability is improved, and simultaneous utilization of electric energy and heat energy is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic thermal systems, and in particular to photovoltaic thermal systems and intelligent agricultural greenhouses. Background Art

[0002] In recent years, the global clean energy industry has entered a stage of rapid development, and more and more countries have begun to accelerate energy transformation. Among the many types of renewable energy, solar energy is internationally recognized as the most competitive renewable energy in the future due to its wide distribution, local availability and low impact on the environment.

[0003] my country's solar energy resources are very rich and widely distributed. More than two-thirds of the country's regions have solar radiation exceeding 5000MJ / m 2 , the annual sunshine hours are more than 2200h. In the field of solar power generation, the most commonly used products are monocrystalline silicon and polycrystalline silicon photovoltaic cell modules. Under standard test conditions (cell temperature is 25℃, solar irradiance is 1000W / m 2 ), the industrial conversion rates of monocrystalline silicon and polycrystalline silicon photovoltaic cells can reach 22% and 18% respectively, while under actual working conditions, the power generation efficiency of photovoltaic cells is only 6%-15%. The reason why there is such a big difference in the power generation efficiency of photovoltaic cells is mainly because: the power generation efficiency of photovoltaic cells is negatively correlated with its temperature. Under actual working conditions, most of the solar radiation energy absorbed by photovoltaic cells will be converted into heat energy, which directly leads to a significant increase in the temperature of photovoltaic cell components, and thus causes a significant decrease in the power generation efficiency of photovoltaic components. Relevant research conclusions show that for every 1°C increase in the temperature of photovoltaic cell components, the power generation power can decrease by 0.5%. Summary of the invention

[0004] In order to improve the above technical defects, the present invention provides a photovoltaic thermal system, comprising:

[0005] Photovoltaic panels;

[0006] A heat storage device containing a liquid medium for storing heat;

[0007] Radiator; and

[0008] A refrigerant circuit, wherein the photovoltaic module, the heat storage device and the radiator are arranged in the refrigerant circuit, and the refrigerant in the refrigerant circuit can exchange heat with the photovoltaic module, the heat storage device and the radiator;

[0009] The refrigerant circuit is configured such that the refrigerant passing through the photovoltaic assembly can be heat-exchanged between the heat storage device and the radiator in a switchable manner.

[0010] In some embodiments, the refrigerant of the refrigerant circuit flows through the back side of the photovoltaic module.

[0011] In some embodiments, when the heat storage device is fully stored with heat, the refrigerant flowing through the photovoltaic module exchanges heat with the heat dissipation device so that the heat dissipation device discharges the heat from the photovoltaic module to the external environment.

[0012] In some embodiments, when the heat storage device is not fully stored with heat, the refrigerant flowing through the photovoltaic module exchanges heat with the heat storage device.

[0013] In some embodiments, a first three-way valve and a second three-way valve are provided in the refrigerant circuit, port A of the first three-way valve and port A of the second three-way valve are respectively connected to the inlet and outlet of the refrigerant circuit flowing through the photovoltaic component, port B of the first three-way valve and port B of the second three-way valve are respectively connected to the outlet and inlet fluids of the heat storage device, port C of the first three-way valve and port C of the second three-way valve are respectively connected to the outlet and inlet fluids of the radiator, wherein port A of the first three-way valve and the second three-way valve are switchably fluidly connected between port B of the first three-way valve and the second three-way valve and port C of the first three-way valve and the second three-way valve.

[0014] In some embodiments, when the heat storage device is fully stored with heat, the B ports of the first three-way valve and the second three-way valve are closed, and the A and C ports of the first three-way valve and the second three-way valve are connected; and when the heat storage device is not fully stored with heat, the C ports of the first three-way valve and the second three-way valve are closed, and the A and B ports of the first three-way valve and the second three-way valve are connected.

[0015] In some embodiments, a system host is provided between the B port of the first three-way valve and the second three-way valve and the heat storage device, the system host including a compressor and a photovoltaic inverter, the compressor is used to drive the refrigerant to flow between the photovoltaic component and the heat storage device; and / or a pump is provided between the C port of the first three-way valve and the second three-way valve and the radiator, the pump is used to drive the refrigerant to flow between the photovoltaic component and the radiator.

[0016] In some embodiments, the photovoltaic thermal system includes an energy storage device for storing electrical energy from the photovoltaic assembly.

[0017] The present invention also provides an intelligent agricultural greenhouse, comprising the above-mentioned photovoltaic thermal system.

[0018] In some embodiments, geothermal pipes are laid in the intelligent agricultural greenhouse, and the liquid medium in the heat storage device circulates in the geothermal pipes.

[0019] In some embodiments, the intelligent agricultural greenhouse includes an in-duct unit, which is configured to perform heat exchange with the refrigerant in the refrigerant circuit to blow dry hot air into the greenhouse.

[0020] In some embodiments, the smart agricultural greenhouse includes a sensor for detecting at least one of humidity and temperature in the greenhouse.

[0021] In some embodiments, when the sensor detects that the humidity is lower than a predetermined humidity or the temperature in the greenhouse is higher than a predetermined temperature, the duct unit is turned off; when the sensor detects that the humidity is higher than a predetermined humidity or the temperature in the greenhouse is lower than a predetermined temperature, the duct unit is started to blow dry hot air into the greenhouse.

[0022] The photovoltaic thermal system according to the present invention reduces the operating temperature of the photovoltaic module, increases the power generation efficiency of the photovoltaic module, improves the operation stability, and realizes the simultaneous utilization of electrical energy and thermal energy.

[0023] The present invention can maintain the temperature of the photovoltaic module within the optimal operating temperature range, significantly improving the power generation efficiency of the photovoltaic module. The entire photovoltaic thermal system can be automatically and intelligently controlled, saving labor and operation and maintenance costs.

[0024] The present invention can improve the efficiency of photovoltaic power generation, collect and utilize the heat of photovoltaic components, and improve the overall utilization efficiency of solar energy. It is widely used in greenhouses, such as agricultural scenarios such as greenhouse planting or breeding. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] According to common practice, the various features of the drawings described below are not necessarily drawn to scale. The sizes of various features and elements in the drawings may be expanded or reduced to more clearly illustrate the embodiments of the present invention.

[0026] Figure 1 is a schematic structural diagram of a photovoltaic thermal system according to an embodiment of the present invention; and

[0027] Figure 2 The schematic diagram of the structure of an intelligent greenhouse using the photovoltaic thermal system of the present invention.

[0028] Figure numerals: 1, photovoltaic module; 2, refrigerant circuit; 7, system host; 8, energy storage device; 9, heat storage device; 10, duct unit; 12, geothermal pipe; 27, pump; 28, radiator; 29, first three-way valve; 30, second three-way valve. DETAILED DESCRIPTION

[0029] The following embodiments of the technical solution of the present invention are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and are therefore only used as examples, and cannot be used to limit the protection scope of the present invention.

[0030] Unless otherwise defined, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by technicians in the technical field to which the present invention belongs; the terms used in the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention; the terms "including" and "having" in the specification and claims of the present invention and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0031] In the description of the embodiments of the present invention, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present invention, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0032] Reference to "embodiments" in the present invention means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in the present invention may be combined with other embodiments.

[0033] In the description of the embodiments of the present invention, the term "and / or" is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, if the character " / " appears in the present invention, it generally indicates that the associated objects before and after are in an "or" relationship.

[0034] In the description of the embodiments of the present invention, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0035] In the description of the embodiments of the present invention, the term "at least one" refers to one or more than two (including two), similarly, "at least one group" refers to one group or more than two (including two), and "at least one piece" refers to one piece or more than two (including two). In the description of the embodiments of the present invention, the term "at least part" refers to part or all.

[0036] Unless otherwise specified, in the description of the embodiments of the present invention, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of 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 cannot be understood as limiting the embodiments of the present invention.

[0037] In the description of the embodiments of the present invention, unless otherwise clearly specified and limited, technical terms such as "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 or an electrical connection; 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 embodiments of the present invention can be understood according to specific circumstances.

[0038] The present invention discloses a photovoltaic thermal system, such as Figure 1 As shown, the photovoltaic thermal system includes a photovoltaic module 1, a heat storage device 9, a radiator 28 and a refrigerant circuit 2. The heat storage device 9 contains a heat storage medium such as water for storing heat. The photovoltaic module 1, the heat storage device 9 and the radiator 28 are arranged in the refrigerant circuit 2. The refrigerant in the refrigerant circuit can be heat-exchanged with the photovoltaic module 1, the heat storage device 9 and the radiator 28. The refrigerant passing through the photovoltaic module 1 can be heat-exchanged switchably between the heat storage device 9 and the radiator 28. When the refrigerant that absorbs the heat of the photovoltaic module 1 switches to heat exchange with the heat storage device 9, the refrigerant that absorbs the heat of the photovoltaic module 1 exchanges heat with the heat storage medium in the heat storage device 9, so that the heat is stored in the heat storage medium. When the refrigerant that absorbs the heat of the photovoltaic module 1 switches to heat exchange with the radiator 28, the heat is dispersed to the external environment. In this way, both solar power generation and heat generation are utilized, and the temperature of the photovoltaic module can be maintained within the optimal operating temperature range, which significantly improves the power generation efficiency of the photovoltaic module.

[0039] In some embodiments of the present invention, the loop of the refrigerant loop 2 flowing through the photovoltaic module 1 is located on the back side of the photovoltaic module 1. This can more efficiently absorb the heat generated by the photovoltaic module 1 when it is working.

[0040] In some embodiments of the present invention, if the heat storage device 9 is full of heat and no heat is needed, the refrigerant flowing through the photovoltaic module 1 is switched to perform heat exchange with the radiator 28, so that the heat sink 9 discharges the heat from the photovoltaic module 1 to the external environment. This ensures that when heat storage and heat are not needed, the excess heat is discharged to the external environment, ensuring that the temperature of the photovoltaic module is maintained within the optimal operating temperature range.

[0041] In some embodiments of the present invention, if the heat storage device 9 is not fully stored with heat, the refrigerant flowing through the photovoltaic module 1 is switched to perform heat exchange with the heat storage device 9. In this way, the heat from the photovoltaic module 1 is collected and stored in the heat storage device 9 for recycling.

[0042] In some embodiments of the present invention, Figure 1 As shown, in order to switch the refrigerant flowing through the photovoltaic component 1 between the heat storage device 9 and the radiator 28, a first three-way valve 29 and a second three-way valve 30 are provided in the refrigerant circuit 2, and the port A of the first three-way valve 29 and the port A of the second three-way valve 30 are respectively connected to the inlet and outlet of the refrigerant circuit flowing through the photovoltaic component 1, the port B of the first three-way valve 29 and the port B of the second three-way valve 30 are respectively connected to the outlet and inlet fluids of the heat storage device 9, and the port C of the first three-way valve 29 and the port C of the second three-way valve 30 are respectively connected to the outlet and inlet fluids of the radiator 28, wherein the port A of the first three-way valve 29 and the second three-way valve 30 can be switchably fluidly connected between the port B of the first three-way valve 29 and the second three-way valve 30 and the port C of the first three-way valve 29 and the second three-way valve 30. When the heat storage device 9 is fully stored with heat, the B ports of the first three-way valve 29 and the second three-way valve 30 are closed, and the A and C ports of the first three-way valve 29 and the second three-way valve 30 are connected; when the heat storage device 9 is not fully stored with heat, the C ports of the first three-way valve 29 and the second three-way valve 30 are closed, and the A and B ports of the first three-way valve 29 and the second three-way valve 30 are connected.

[0043] In some embodiments of the present invention, Figure 1 As shown, a system host 7 is provided between the B ports of the first three-way valve 29 and the second three-way valve 30 and the heat storage device 9. The system host includes a compressor and a photovoltaic inverter. The compressor is used to drive the refrigerant to flow between the photovoltaic component 1 and the heat storage device 9.

[0044] In some embodiments of the present invention, Figure 1As shown, a pump 27 is provided between the C port of the first three-way valve 29 and the second three-way valve 30 and the radiator 28, and the pump is used to drive the refrigerant to flow between the photovoltaic module 1 and the radiator 28, which is conducive to heat exchange between the refrigerant and the photovoltaic module 1 and the radiator 28. In this way, when the heat in the heat storage device 9 reaches the upper limit and the heat cannot be consumed, the system will automatically switch the heat dissipation mode after detecting that there is no need for heat. The A and C ports of the first and second three-way valves are connected, and the pump 27 is turned on to circulate the refrigerant in the refrigerant circuit. The heat behind the photovoltaic module is brought to the fins of the radiator, and the fan allows the heat to be quickly dissipated, so that the efficiency of photovoltaic power generation can be improved even when heat is not needed.

[0045] In some embodiments of the present invention, the photovoltaic thermal system includes an energy storage device 8, which is connected to the photovoltaic inverter in the host system and is used to store the electrical energy from the photovoltaic module 1 and supply power to the electrical equipment when electricity is needed. The photovoltaic thermal system can not only meet its own electricity and heat needs, but also store excess electricity and heat for use in insufficient light or at night, achieving zero carbon emissions.

[0046] like Figure 2 As shown, the present invention also provides an intelligent agricultural greenhouse, including the above-mentioned photovoltaic thermal system. The present invention can improve the utilization efficiency of solar energy. The traditional photovoltaic system only uses the electricity generated by photovoltaic power generation, and a large amount of heat is wasted. The present invention can achieve all-weather photovoltaic power generation efficiency improvement, and at the same time collect and utilize the heat of the photovoltaic components, thereby improving the overall utilization efficiency of solar energy, and can be widely used in greenhouses such as greenhouse planting or breeding and other agricultural scenes.

[0047] In some embodiments of the present invention, Figure 2 As shown, a geothermal pipe 12 is laid in the intelligent agricultural greenhouse, and the geothermal pipe is fluidly connected to the liquid medium in the heat storage device 9. The hot liquid medium circulates in the geothermal pipe 12, releases heat in the greenhouse to heat the greenhouse, and absorbs heat in the heat storage device 9. In this way, when the photovoltaic module receives sunlight, the photovoltaic module generates current through the photovoltaic effect, and the photovoltaic inverter flowing through the system host converts direct current into alternating current or directly supplies direct current loads through the DC bus. If the load power consumption is less than the photovoltaic power generation, the excess power will be connected to the grid. The backplane temperature of the photovoltaic module will continue to rise, usually reaching about 60°C. The first and second three-way valves A and B ports are connected, the compressor in the system host is started, and the refrigerant in the refrigerant circuit takes away the heat from the back of the photovoltaic module, and the heat is stored in the heat storage medium in the heat storage device. When the greenhouse needs heat, the heat storage medium flows through the pre-buried underground floor heating pipe to heat the greenhouse, and can also blow out dry hot air through the air duct machine to achieve the purpose of heating and dehumidification.

[0048] In some embodiments of the present invention, Figure 2 As shown, the agricultural greenhouse includes an air duct internal unit 10, which can perform heat exchange with the refrigerant in the refrigerant circuit 2 to blow the dry hot air obtained after the heat exchange into the greenhouse for the purpose of heating and dehumidification, so as to adjust the temperature and humidity of the greenhouse. The entire photovoltaic thermal system can be automatically and intelligently controlled, saving labor and operation and maintenance costs.

[0049] In some embodiments of the present invention, Figure 2 As shown, the intelligent agricultural greenhouse includes a sensor for detecting at least one of the humidity and temperature in the greenhouse to monitor the greenhouse environment in real time. If the sensor detects that the humidity is higher than a predetermined humidity or the temperature in the greenhouse is lower than a predetermined temperature, the duct internal unit 10 is activated to blow dry hot air into the greenhouse, which is conducive to the greenhouse being in a constant temperature and humidity state.

[0050] The foregoing description of the present invention illustrates and describes some exemplary embodiments. Without departing from the spirit and scope of the present invention, various additions, modifications, changes, etc. may be made to these exemplary embodiments. It is intended that all contents contained in the above description or shown in the accompanying drawings be interpreted as illustrative, rather than restrictive. In addition, the present invention only illustrates and describes selected embodiments of the present invention, but within the scope of the inventive concept as expressed herein, commensurate with the above teachings, and / or within the skills or knowledge of those skilled in the relevant art, the present invention can be used in various other combinations, modifications and environments and can be changed or modified. In addition, certain features and characteristics of each embodiment can be selectively interchanged and applied to other illustrated and unillustrated embodiments of the present invention.

Claims

1. A photovoltaic thermal system, comprising: Photovoltaic modules (1); A heat storage device (9) containing a liquid medium for storing heat; a heat sink (28); and A refrigerant circuit (2), wherein the photovoltaic module (1), the heat storage device (9) and the radiator (28) are arranged in the refrigerant circuit (2), and the refrigerant in the refrigerant circuit can exchange heat with the photovoltaic module (1), the heat storage device (9) and the radiator (28); The refrigerant circuit (2) is configured such that the refrigerant passing through the photovoltaic assembly (1) can be heat-exchanged switchably between the heat storage device (9) and the radiator (28).

2. The photovoltaic thermal system according to claim 1, wherein the refrigerant in the refrigerant circuit (2) flows through the back side of the photovoltaic component (1).

3. The photovoltaic thermal system according to claim 1, wherein when the heat storage device (9) is fully filled with heat, the refrigerant flowing through the photovoltaic module (1) exchanges heat with the heat dissipation device (9), so that the heat dissipation device (9) discharges the heat from the photovoltaic module (1) to the external environment.

4. The photovoltaic thermal system according to claim 1, wherein when the heat storage device (9) is not fully filled with heat, the refrigerant flowing through the photovoltaic module (1) performs heat exchange with the heat storage device (9).

5. The photovoltaic thermal system according to claim 3 or 4, wherein a first three-way valve (29) and a second three-way valve (30) are provided in the refrigerant circuit (2), port A of the first three-way valve (29) and port A of the second three-way valve (30) are respectively connected to the inlet and outlet of the refrigerant circuit flowing through the photovoltaic assembly (1), port B of the first three-way valve (29) and port B of the second three-way valve (30) are respectively connected to the outlet and inlet fluids of the heat storage device (9), port C of the first three-way valve (29) and port C of the second three-way valve (30) are respectively connected to the outlet and inlet fluids of the radiator (28), wherein port A of the first three-way valve (29) and the second three-way valve (30) are switchably connected to the fluid between port B of the first three-way valve (29) and the second three-way valve (30) and port C of the first three-way valve (29) and the second three-way valve (30); When the heat storage device (9) is fully charged with heat, the B ports of the first three-way valve (29) and the second three-way valve (30) are closed, and the A and C ports of the first three-way valve (29) and the second three-way valve (30) are connected; and When the heat storage device (9) is not fully heated, the C ports of the first three-way valve (29) and the second three-way valve (30) are closed, and the A and B ports of the first three-way valve (29) and the second three-way valve (30) are connected.

6. The photovoltaic thermal system according to claim 5, wherein: A system host (7) is provided between the B ports of the first three-way valve (29) and the second three-way valve (30) and the heat storage device (9), the system host comprising a compressor and a photovoltaic inverter, the compressor being used to drive the refrigerant to flow between the photovoltaic assembly (1) and the heat storage device (9); and / or A pump (27) is provided between the C ports of the first three-way valve (29) and the second three-way valve (30) and the radiator (28), and the pump is used to drive the refrigerant to flow between the photovoltaic assembly (1) and the radiator (28).

7. The photovoltaic thermal system according to claim 1, comprising an energy storage device (8) for storing electrical energy from the photovoltaic assembly (1).

8. An intelligent agricultural greenhouse, comprising the photovoltaic thermal system according to any one of claims 1-7.

9. The intelligent agricultural greenhouse according to claim 8, wherein geothermal pipes (12) are laid in the intelligent agricultural greenhouse, and the liquid medium in the heat storage device (9) circulates in the geothermal pipes.

10. The intelligent agricultural greenhouse according to claim 8, comprising an air duct internal unit (10), wherein the air duct internal unit (10) is configured to perform heat exchange with the refrigerant in the refrigerant circuit (2) to blow dry hot air into the greenhouse.

11. The intelligent agricultural greenhouse according to claim 8, comprising a sensor for detecting at least one of humidity and temperature in the greenhouse.

12. The intelligent agricultural greenhouse according to claim 11, wherein: When the sensor detects that the humidity is higher than a predetermined humidity or the temperature in the greenhouse is lower than a predetermined temperature, the duct unit (10) is activated to blow dry hot air into the greenhouse.

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