A miniaturized focusing and frequency division solar photovoltaic / photothermal device and control method

Abstract

The present invention discloses a miniaturized concentrating and frequency-splitting solar photovoltaic / photothermal device and control method, the device comprising: a heliostat, a parabolic trough linear concentrator is arranged on the reflected light path of the heliostat, a frequency divider is arranged on the reflected light path of the parabolic trough linear concentrator, two light paths separated by the frequency divider are respectively provided with a vacuum heat collecting tube and a photovoltaic cell array, the vacuum heat collecting tube is connected to a heat storage device; wherein the frequency divider comprises a frequency dividing film, the thickness of the frequency dividing film is determined by: calculating the required cut-off wavelength range according to the thermal power distribution requirements; calculating the thickness of the frequency dividing film according to the cut-off wavelength range. The present invention can improve the solar energy conversion rate while realizing energy distribution that meets the requirements of specific places.

Description

Technical Field

[0001] The present invention belongs to the technical field of comprehensive utilization of solar energy, and in particular relates to a miniaturized focusing and frequency-splitting solar photovoltaic / photothermal device and a control method thereof. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] Based on the fact that the short-wave part of full-spectrum solar energy exhibits a photoelectric effect, and the long-wave part exhibits a photothermal effect, the use of a spectrum frequency division device to concentrate short-wave light on photovoltaic power generation and long-wave light on photothermal conversion can improve the comprehensive utilization efficiency of solar energy. However, due to the dispersed characteristics of sunlight, how to concentrate the dispersed sunlight on the photovoltaic / photothermal unit is the main problem in improving the comprehensive utilization efficiency of solar energy.

[0004] In addition, the comprehensive utilization of solar energy in the prior art usually focuses on how to achieve higher energy utilization, including the utilization of solar energy, converting solar energy into more heat and more electricity, as well as the utilization of the converted heat and electricity, and how to store and utilize energy in different seasons or at different times, and how to perform time-sharing control. However, in reality, the heat and electricity demands of different places are different. Some places have a greater demand for heat than for electricity, such as industrial plants, and some places have a greater demand for electricity than for heat, such as shopping malls and hospitals. The existing solar thermal cogeneration devices do not provide solutions that can meet the heat and electricity demands of specific places. Summary of the invention

[0005] In order to overcome the above-mentioned deficiencies of the prior art, the present invention provides a miniaturized concentrated frequency-divided solar photovoltaic / photothermal device and a control method. The present invention can improve the solar energy conversion rate while achieving energy distribution that meets the needs of specific places.

[0006] To achieve the above objectives, one or more embodiments of the present invention provide the following technical solutions:

[0007] A miniaturized concentrating and frequency-splitting solar photovoltaic / photothermal device comprises: a heliostat, a parabolic trough linear concentrator is arranged on the reflected light path of the heliostat, a frequency divider is arranged on the reflected light path of the parabolic trough linear concentrator, two light paths separated by the frequency divider are respectively provided with a vacuum heat collecting tube and a photovoltaic cell array, and the vacuum heat collecting tube is connected to a heat storage device; wherein the frequency divider comprises a frequency dividing film, and a method for determining the thickness of the frequency dividing film is as follows: according to the thermal power distribution demand, a required cut-off wavelength range is calculated; according to the cut-off wavelength range, the thickness of the frequency dividing film is calculated.

[0008] In some embodiments, the thermal power distribution demand is a thermal energy demand ratio; a corresponding table of thermal energy ratio and cut-off wavelength range is prepared in advance, and after obtaining the thermal energy demand ratio, the corresponding cut-off wavelength range is determined by looking up the table.

[0009] In some embodiments, multiple possible cutoff wavelength ranges are obtained, the thermal energy proportions corresponding to the multiple cutoff wavelength ranges are calculated, and the cutoff wavelength range whose thermal energy proportion meets the requirements is selected.

[0010] In some embodiments, the heat accumulator is arranged on the ground, and at least two parallel inverted "L"-shaped brackets are provided on the heat accumulator, the other end of the inverted "L"-shaped bracket is connected to a parabolic trough linear concentrator, and a divider and a vacuum collector tube are provided below the parabolic trough linear concentrator in sequence, and both ends of the vacuum collector tube are connected to the heat accumulator; the photovoltaic cell array is installed between the parallel inverted "L"-shaped brackets, and the height is adapted to the divider.

[0011] In some embodiments, the device further comprises a heat supply system and a heat-to-electricity system, both of which are connected in parallel with the heat storage device.

[0012] In some embodiments, the heating system includes a heat exchanger and an insulated water tank connected to the heat exchanger, and the insulated water tank is used to provide thermal energy to the user end.

[0013] In some embodiments, the device further comprises a water heater connected to a water network, wherein the water heater is used to provide additional heat energy to a user end when the heat preservation water tank cannot meet the heat demand.

[0014] One or more embodiments of the present invention provide a control method for the solar photovoltaic / thermal device, for a place where the heat demand is greater than the electricity demand:

[0015] When the solar radiation intensity is greater than the set high threshold, the heating system is controlled to work, and the thermal water tank provides heat to the user end; when the heat demand is met, the heat-to-electricity system is controlled to work and generate heat;

[0016] When the solar radiation intensity is within the set medium threshold range, the heating system is controlled to work, and the heat preservation water tank provides heat to the user end; the heat-to-electricity system does not work;

[0017] When the solar radiation intensity is less than the set lower threshold, the heating system is controlled to operate, and the insulated water tank provides heat to the user end. If the heat demand cannot be met, the water heater is turned on; the heat-to-electricity system does not operate.

[0018] In some embodiments, for places where electricity demand is greater than heat demand:

[0019] When the solar radiation intensity is greater than the set high threshold, the heat-to-electricity system is controlled to operate and generate thermal power; when the electricity demand is met, the heating system is controlled to operate and the excess heat is stored in the thermal water tank;

[0020] When the solar radiation intensity is within the set medium threshold range, the heat-to-electricity system is controlled to operate and generate thermal power; the heating system does not operate;

[0021] When the solar radiation intensity is less than the set low threshold, the heating system is controlled to operate and store heat in the thermal insulation water tank.

[0022] In some embodiments, if there is a demand for heat when the heating system is not operating, the water heater is turned on.

[0023] One or more of the above technical solutions have the following beneficial effects:

[0024] After the heliostat and parabolic trough linear concentrator reflect the optical fiber twice, the focusing multiple can be effectively improved, greatly increasing the energy density reaching the subsequent frequency divider, ensuring that more energy can be converted into heat and electricity. On this basis, by optimizing the thickness of the frequency division film and controlling the wavelength range of the frequency division, the conversion ratio of solar energy to heat and electricity can be controlled to meet the personalized thermoelectric needs of users, so that the device can better meet the needs of places with specific energy needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0026] Figure 1 It is a schematic diagram of the overall structure of a miniaturized focusing and frequency division solar photovoltaic / photothermal device in an embodiment of the present invention;

[0027] Figure 2 Schematic diagram of a heating system and a heat-to-electricity system in an embodiment of the present invention.

[0028] In the figure, 1. heliostat, 2. heat exchanger, 3. heat-to-electricity system, 4. inverted "L"-shaped bracket, 5. parabolic trough linear concentrator, 6. infrared frequency-dividing glass, 7. frequency-dividing film, 8. photovoltaic cell array, 9. vacuum collector tube, 10. heat storage device, 11. insulated water tank, 12. water heater, 13. user end. DETAILED DESCRIPTION

[0029] The embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although certain embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be construed as being limited to the embodiments described herein. Instead, these embodiments are provided to provide a more thorough and complete understanding of the present application. It should be understood that the drawings and embodiments of the present application are only for exemplary purposes and are not intended to limit the scope of protection of the present application.

[0030] In the description of the embodiments of the present application, the term “including” and similar terms should be understood as open inclusion, that is, “including but not limited to.” The term “based on” should be understood as “based at least in part on.”

[0031] As described in the background technology, the comprehensive utilization of solar energy in the prior art usually focuses on how to achieve higher energy utilization. However, the heat demand and electricity demand of different places are different. Some places have a greater demand for heat than for electricity, such as industrial plants, and some places have a greater demand for electricity than for heat, such as shopping malls and hospitals. The existing solar thermal power cogeneration device does not provide a solution that can meet the heat and electricity needs of specific places.

[0032] One or more embodiments of the present invention provide a miniaturized concentrating and frequency-dividing solar photovoltaic / photothermal device, which can be applied to industrial plants, shopping malls, schools and other places, and can optimize the thickness of the frequency-dividing film according to the heat demand and electricity demand of the specific place, so as to achieve the optimal distribution of energy while meeting the heat / electricity demand of the specific place. As a specific implementation method, the miniaturized concentrating and frequency-dividing solar photovoltaic / photothermal device includes a heliostat 1, a concentrating and frequency-dividing power generation unit, and a photothermal conversion unit. The concentrating and frequency-dividing power generation unit includes a parabolic trough linear concentrator 5, a frequency divider and a photovoltaic cell array 8. The photothermal conversion unit includes a vacuum collector tube 9, a heat accumulator 10, a heat exchanger 2 and a heat-to-electricity system 3. The parabolic trough linear concentrator 5 is arranged on the reflected light path of the heliostat, the frequency divider is arranged on the reflected light path of the parabolic trough linear concentrator 5, the vacuum heat collecting tube 9 and the photovoltaic cell array 8 are respectively arranged on the two light paths separated by the frequency divider, and the vacuum heat collecting tube 9 is connected to the heat storage device 10 to store heat through a self-circulation process. Based on the principle of focusing and frequency division, the optimal matching of the photovoltaic / photothermal conversion process characteristics and the medium / long and short wave bands is ensured through the design of different optical paths and frequency division bands, thereby realizing the efficient and comprehensive utilization of full-spectrum solar energy.

[0033] The frequency divider includes an infrared frequency dividing glass 6 and a frequency dividing film 7 plated on the infrared frequency dividing glass. The thickness of the frequency dividing film 7 is determined by: calculating the required cutoff wavelength range according to the thermal power distribution requirements; and calculating the thickness of the frequency dividing film according to the cutoff wavelength range.

[0034] As a specific implementation method, the thermal power distribution demand is the proportion of thermal energy demand; a corresponding table of thermal energy proportion and cut-off wavelength range is prepared in advance, and after obtaining the thermal energy demand proportion, the corresponding cut-off wavelength range is determined by looking up the table. As an example, according to the standard table of solar spectrum irradiance referenced by ASTM G173-03, the corresponding table of thermal energy proportion and cut-off wavelength range is prepared, as shown in Table 1, which includes the cut-off wavelength range when the thermal energy proportion increases by 5%. When the thermal energy proportion is 5%, the cut-off wavelength range is 280nm-416nm, and when the thermal energy proportion is 25%, the thermal energy proportion is 525nm-559nm.

[0035] Table 1 Example of corresponding table of thermal energy proportion and cut-off wavelength range

[0036]

[0037]

[0038] However, due to the influence of factors such as the material and coating process of the subsequent frequency-dividing film, the cut-off wavelength range is often not consistent with the upper and lower limits of the wavelength range in the table. Therefore, the thermal energy proportions corresponding to the multiple cut-off wavelength ranges that can be actually achieved can be calculated to determine whether the thermal energy proportions meet the requirements, and then determine the required cut-off wavelength range. In this way, under the constraints of factors such as the frequency-dividing film material, a cut-off wavelength range that meets the requirements can be obtained, thereby achieving thickness optimization of the frequency-dividing film.

[0039] Taking the cut-off wavelength range of 400nm-800nm ​​as an example, it can be seen from Table 1 that the upper limit of the cut-off wavelength range is between 280-416 in the first row, and the lower limit is between 786-835 in the 12th row, then the calculation formula for the thermal energy proportion is:

[0040] (416-400) / (416-280)*5+5*10+(800-786) / (835-756)*5=52.01%,

[0041] Correspondingly, the proportion of photovoltaics is: 1-52.01%=47.99%.

[0042] Taking the cut-off wavelength range of 400nm-1200nm as an example, it can be seen from Table 1 that the upper limit of the cut-off wavelength range is between 280-416 in the first row, and the lower limit is between 1140-1257 in the 17th row, then the calculation formula for the thermal energy proportion is:

[0043] (416-400) / (416-280)*5+5*15+(1200-1140) / (1257-1140)*5=78.99%,

[0044] Correspondingly, the proportion of photovoltaics is: 1-78.99%=21.01%.

[0045] As an example, for places such as industrial plants where the demand for heat is greater than the demand for electricity, such as printing machine equipment used in printing and dyeing plants, which requires hot steam at about 150°C and 0.49MPa, the spectrum wavelengths λ1-λ2 can be cut off to the range of 400-800nm. Accordingly, the photothermal part accounts for 47.99% of the total solar energy, and the photovoltaic part accounts for 52.01% of the total solar energy. Light outside the cut-off wavelength range enters the vacuum heat collecting tube 9 for photothermal reaction, and light within the wavelength range enters the photovoltaic cell array 8 through the infrared frequency-dividing glass 6.

[0046] As another example, for commercial areas where electricity demand is greater than heat demand, such as shopping malls, schools, etc., the spectrum wavelengths λ1-λ2 can be cut off to the range of 400-1200nm, and accordingly, the photovoltaic part accounts for 78.99% of the full spectrum solar energy, and the photothermal part accounts for 21.01% of the full spectrum solar energy. Light outside the cut-off wavelength range enters the heat collecting tube 9 for photothermal reaction, and light within the wavelength range enters the photovoltaic cell array 8 through the infrared frequency-dividing glass 6.

[0047] The heliostat 1 reflects the incident sunlight received once, and the parabolic trough concentrator 5 reflects the light reflected from the heliostat 1 twice. Since the parabolic trough linear concentrator 5 can effectively increase the concentration multiple (experimentally tested, it can be increased by 20 times), it can greatly increase the energy density reaching the subsequent frequency divider, ensuring that more energy can be converted into heat and electrical energy. On this basis, by optimizing the thickness of the frequency division film, the wavelength range of the frequency division can be controlled, for example, the sunlight in the wavelength range of λ1 to λ2 is controlled to be reflected to the photovoltaic cell array through the infrared glass for photoelectric conversion, and the sunlight outside the wavelength range of λ1 to λ2 is transmitted to the vacuum collector tube through the infrared frequency division glass for photothermal conversion, thereby realizing the conversion ratio control of solar energy into heat and electrical energy, meeting the personalized thermal power needs of users, and making the device more meet the needs of specific energy demand sites.

[0048] In order to achieve miniaturization of the device, in some embodiments, structures such as the parabolic trough linear concentrator 5, a divider, a photovoltaic cell array 8 and a vacuum heat collecting tube 9 are integrated. Specifically, the heat accumulator 10 is arranged on the ground, and at least two parallel inverted "L"-shaped brackets 4 are provided on the heat accumulator 10. The other end of the inverted "L"-shaped bracket 4 is connected to the parabolic trough linear concentrator 5. A divider and a vacuum heat collecting tube 9 are arranged below the parabolic trough linear concentrator 5 in sequence, and both ends of the vacuum heat collecting tube 9 are connected to the heat accumulator; the photovoltaic cell array 8 is installed between the parallel inverted "L"-shaped brackets 4, and the height is adapted to the divider. As an example, the height of the divider can be located in the middle of the straight-line distance between the parabolic trough linear concentrator 3 and the vacuum heat collecting tube 9; the divider is connected to the ground through a bracket (not shown in the figure). Based on this, the heat accumulator 10 is used to store thermal energy and provide support for the parabolic trough linear concentrator 5 and the vacuum collector tube 9, thereby improving the system integration and reducing the footprint, which is more in line with the demand for devices in smaller areas such as factories, schools, and hospitals.

[0049] In order to avoid obstruction of the light path reflected by the infrared frequency dividing glass 6 and to maintain the neatness of the overall structure of the system, the angle between the frequency divider and the horizontal plane is 45° and is inclined toward the photovoltaic cell array 8.

[0050] It can be understood that the lengths of the frequency divider, the parabolic trough concentrator 3 and the vacuum heat collecting tube 9 are consistent.

[0051] As a more specific example, the heliostat 1 faces south so as to capture solar radiation to the maximum extent and ensure that sunlight is received most of the time in a day; to ensure the stability of the optical path, the heliostat 1 is installed at a horizontal position of 5 to 10 meters away from the parabolic trough linear concentrator 3, the infrared frequency-dividing glass 6 is installed at the center of the parabolic trough linear concentrator 3 and the vacuum collector tube 9, the parabolic trough linear concentrator 3 is 2 to 3 meters away from the vacuum collector tube, and the photovoltaic cell array 8 is located at a distance of 0.5 to 1 meter from the infrared frequency-dividing glass 6 to receive short-wave light reflected from the infrared frequency-dividing glass 6.

[0052] Once the thickness of the frequency-dividing film is determined, it is difficult to replace the frequency divider after the device is installed. However, when the solar radiation intensity is high, the converted heat may exceed the user's needs. Therefore, in order to improve the flexibility of the device, in some embodiments, the device also includes a heat exchanger 2 and a 300℃-70℃ heat-to-electricity system 3, both of which are connected in parallel with the heat storage device 10, so that when the generated heat exceeds the required thermal energy, it is converted into electrical energy, which makes up for the defect that the cut-off wavelength range cannot be changed once the device is installed. Figure 2As shown, the vacuum heat collecting tube 9 is connected to the heat accumulator 10, and the light transmitted through the infrared frequency-dividing glass 6 is heat-circulated and the heat is stored in the heat accumulator 10. The heat accumulator 10 is connected to the heat exchanger 2 and the 300℃-70℃ heat-to-electricity system 3, wherein the heat exchanger 2 and the 300℃-70℃ heat-to-electricity system 3 are connected in parallel. The heat stored in the heat accumulator 10 can be used for heat utilization through the heat exchanger 2, and can also be used for thermal power generation through the 300℃-70℃ heat-to-electricity system 3, so as to meet the different needs of the user end 13. The electric energy generated by the heat-to-electricity system 3 can meet the energy consumption needs of the system itself, saving additional energy consumption.

[0053] The heat exchanger 2 is also connected to an insulated water tank 11, which is used to provide heat energy to the user end 13; in addition, the device also includes a water heater 12 connected to the water network, and the water heater 12 is used to provide additional heat energy to the user end 13 when the insulated water tank 11 cannot meet the heating demand.

[0054] As an example, for places such as industrial plants where the heat demand is greater than the electricity demand, when the solar radiation intensity is good (such as greater than 800W / m2), the heat generated by the system can be directly stored in the heat-insulating water tank 11 by the heat exchanger 11, and the heat demand of the user end 13 can be directly supplied by the heat generated by the system. After the heat demand of the user end 13 is met, the excess heat enters the 300℃-70℃ heat-to-electricity system 3 for thermal power generation, and the electricity generated by the system can be used to meet the energy consumption needs of the system itself, saving an amount of When the solar radiation intensity is medium (such as 400-800W / m2), the heat generated by the system is stored in the insulated water tank 11, and the heat is supplied to the user end 13. The 300℃-700℃ heat-to-electricity system 3 does not work, and electricity generation relies on the photovoltaic cell array 8. When the solar radiation intensity is poor (such as less than 400W / m2), the heat required by the user end 13 cannot be directly met by solar energy, and should be supplied by the insulated water tank 11 first. When the heat is insufficient, the water heater 12 is turned on to compensate.

[0055] As another example, for commercial areas where the demand for electricity is greater than the demand for heat, such as shopping malls, schools, etc., when the solar radiation intensity is good (such as greater than 800W / m2), the heat generated by the system is preferentially used for thermal power generation through the 300℃-70℃ heat-to-electricity system 3, and the excess heat is stored in the insulated water tank 11. If the user end 13 has a heat demand, the heat can be directly obtained from the insulated water tank 11; when the solar radiation intensity is medium (such as 400-800W / m2), the heat generated by the system is still preferentially used for thermal power generation through the 300℃-70℃ heat-to-electricity system 3, and the heat exchanger 11 and the thermal equipment of the insulated water tank 11 do not work. If there is a heat demand, the heat is provided by the water heater 12. When the solar radiation intensity is poor (such as less than 400W / m2), the heat energy generated by the system may not be able to be supplied by the 300℃-70℃ heat-to-electricity system 3, so the heat is stored in the insulated water tank 11 for heat supply when needed. At this time, the system only relies on the electricity generated by the photovoltaic cell array 8 to meet the energy demand of the user end 13.

[0056] By connecting the heating system and the heat-to-electricity system in parallel on the basis of the heat storage device, a flexible and adjustable control method is provided to address the defect that the cut-off wavelength range cannot be changed after the thickness of the frequency-dividing film is determined and installed. When the heating supply is greater than the heating demand, the excess heat can be converted into electrical energy. When the electricity demand is large, the thermal energy can also be converted into electrical energy, thereby being able to cope with more diverse energy demands in specific scenarios.

[0057] In view of the differences in electric heating demand in different places, appropriate adjustments should be made based on the control system according to the needs of users in different seasons. For example, when focusing on heating conditions in winter, it is possible to consider connecting the system power output to the water heater 12 to ensure the heating demand in winter. For the summer bathing and air-conditioning electricity demand conditions, the solar energy can be absorbed to the maximum extent by flexibly adjusting the 300℃-70℃ heat-to-electricity system 3 and coordinating with the air-conditioning, while ensuring the priority use of the insulation water tank 11. If there is still excess solar energy, the solar energy input can be partially abandoned by adjusting the heliostat 1 to ensure system safety. Under rated operating conditions, full-spectrum sunlight can be received and fully utilized by the concentrated and divided-frequency solar photovoltaic / photothermal device, and the photovoltaic / photothermal comprehensive efficiency can reach 82.3%.

[0058] Although the subject matter has been described in language specific to structural features and / or methodological logical actions, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or actions described above. On the contrary, the specific features and actions described above are merely example forms of implementing the claims.

Claims

1. A miniaturized concentrated frequency-divided solar photovoltaic / photothermal device, characterized in that: include: A heliostat, wherein a parabolic trough linear condenser is arranged on a reflected light path of the heliostat, a frequency divider is arranged on the reflected light path of the parabolic trough linear condenser, two light paths separated by the frequency divider are respectively provided with a vacuum heat collecting tube and a photovoltaic cell array, and the vacuum heat collecting tube is connected to a heat storage device; wherein the frequency divider includes a frequency dividing film, and a method for determining the thickness of the frequency dividing film is as follows: according to a thermal power distribution demand, a required cut-off wavelength range is calculated; according to the cut-off wavelength range, the thickness of the frequency dividing film is calculated.

2. The miniaturized concentrated frequency-divided solar photovoltaic / photothermal device according to claim 1, characterized in that: The thermal power distribution demand is the proportion of thermal energy demand; a corresponding table of thermal energy proportion and cut-off wavelength range is prepared in advance, and after obtaining the thermal energy demand proportion, the corresponding cut-off wavelength range is determined by looking up the table.

3. The miniaturized concentrated frequency-divided solar photovoltaic / photothermal device according to claim 2, characterized in that: Acquire multiple possible cutoff wavelength ranges, calculate the thermal energy proportions corresponding to the multiple cutoff wavelength ranges, and select a cutoff wavelength range whose thermal energy proportion meets the requirements.

4. The miniaturized concentrated frequency-divided solar photovoltaic / photothermal device according to claim 1, characterized in that: The heat accumulator is arranged on the ground, and at least two parallel inverted "L"-shaped brackets are arranged on the heat accumulator. The other end of the inverted "L"-shaped bracket is connected to a parabolic trough linear condenser. A divider and a vacuum heat collecting tube are arranged in sequence below the parabolic trough linear condenser, and both ends of the vacuum heat collecting tube are connected to the heat accumulator; the photovoltaic cell array is installed between the parallel inverted "L"-shaped brackets, and the height is adapted to the divider.

5. The miniaturized concentrated frequency-divided solar photovoltaic / photothermal device according to claim 1, characterized in that: The device also includes a heat supply system and a heat-to-electricity system, both of which are connected in parallel with the heat accumulator.

6. The miniaturized concentrated frequency-divided solar photovoltaic / photothermal device according to claim 5, characterized in that: The heating system comprises a heat exchanger and a heat-insulating water tank connected to the heat exchanger, and the heat-insulating water tank is used to provide heat energy to the user end.

7. The miniaturized concentrated frequency-divided solar photovoltaic / photothermal device according to claim 6, characterized in that: The device also includes a water heater connected to the water network, and the water heater is used to provide additional heat energy to the user end when the thermal insulation water tank cannot meet the heat demand.

8. A control method for a solar photovoltaic / photothermal device according to any one of claims 1 to 7, characterized in that: For places where heat demand is greater than electricity demand: When the solar radiation intensity is greater than the set high threshold, the heating system is controlled to work, and the thermal water tank provides heat to the user end; when the heat demand is met, the heat-to-electricity system is controlled to work and generate heat; When the solar radiation intensity is within the set medium threshold range, the heating system is controlled to work, and the heat preservation water tank provides heat to the user end; the heat-to-electricity system does not work; When the solar radiation intensity is less than the set lower threshold, the heating system is controlled to operate, and the insulated water tank provides heat to the user end. If the heat demand cannot be met, the water heater is turned on; the heat-to-electricity system does not operate.

9. The control method according to claim 8, characterized in that: For places where electricity demand is greater than heat demand: When the solar radiation intensity is greater than the set high threshold, the heat-to-electricity system is controlled to operate and generate thermal power; when the electricity demand is met, the heating system is controlled to operate and the excess heat is stored in the thermal water tank; When the solar radiation intensity is within the set medium threshold range, the heat-to-electricity system is controlled to operate and generate thermal power; the heating system does not operate; When the solar radiation intensity is less than the set low threshold, the heating system is controlled to operate and store heat in the thermal insulation water tank.

10. The control method according to claim 9, characterized in that: If there is a demand for heat when the heating system is not working, the water heater is turned on.

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