Building energy supply system based on solar light / heat / electricity co-production

Abstract

The invention relates to a building energy supply system based on solar light / heat / power cogeneration. The building energy supply system comprises a light-heat-power cogeneration unit, a lighting side, a heat supply side and a power supply side. A lens at the top end of the light-heat-power cogeneration unit receives sunlight, the light-heat-power cogeneration unit divides the sunlight into visible light and infrared light, and the visible light is directly coupled into a light guide pipe on the illumination side to illuminate the illumination side of a building. The infrared light is utilized by a photovoltaic cell to generate electric energy which is transmitted to a building power supply side to provide electric energy for a load; and the heat of the photovoltaic cell is taken away by the immersed cooling working medium in the enclosing structure and is conveyed to the heat supply side of the building to provide heat energy. Compared with the prior art, the light-heat-electricity requirements of a building can be met at the same time; the utilization efficiency of solar energy is improved; the problem of non-uniform space-time distribution in building energy utilization can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of efficient utilization of solar energy, and in particular to a building energy supply system based on solar light / heat / electricity cogeneration. Background Art

[0002] At present, in order to cope with the problems of global environmental deterioration and resource shortage, it is urgent to develop renewable clean green energy. As the best source of green renewable energy, the comprehensive utilization of solar energy has received widespread attention. At present, building energy consumption accounts for about 36% of the world's total energy consumption, of which lighting energy consumption accounts for a high proportion. However, due to the existence of many closed environments such as high-rise buildings and plant production factories, sunlight cannot be directly irradiated. Using all electric energy for lighting will cause a huge waste of resources. Light-guiding lighting is considered to be one of the most direct and effective ways of solar buildings, which can save a lot of lighting costs. Light-guiding lighting technology is to use optical fiber or light-guiding tube technology to directly guide sunlight into the room for lighting. Among them, optical fiber technology is widely used for its flexible performance and long-distance transmission capability. Its principle is mainly to use concentrated solar collectors, such as Fresnel lenses, to capture high-intensity sunlight and transmit it to the indoor environment through optical fibers. However, the solar spectrum not only contains the visible light (VIS) band (380-780nm) that can provide lighting functions, but also the infrared band (780-3000nm) that can generate heat. Most of the energy in the infrared band is concentrated in the near-infrared (NIR) band (780-1100nm). This heat is redundant for many indoor environments (especially in areas with lower latitudes). At the same time, the materials of light-guiding optical fibers are mainly divided into quartz and polymethyl methacrylate (PMMA), which have limited tolerance to high temperatures. If infrared light is directly coupled into the optical fiber without attenuation, the excessively high temperature generated may reduce the performance of the optical fiber or even melt the optical fiber. Therefore, separating or utilizing infrared light from the solar spectrum that enters the optical fiber is a technical problem that needs to be solved urgently.

[0003] At present, the frequency division method for fiber-optic light-guiding buildings is mostly aimed at separating infrared light to prevent it from entering the optical fiber and causing the fiber to melt. However, the energy in the infrared light is less utilized, resulting in a decrease in the utilization rate of solar energy. Therefore, some scholars use the separated infrared spectrum energy to supply photovoltaic cells to generate electricity. This energy utilization method requires detailed design and optimization of the structure and angle of the device, and the current research is relatively insufficient. In addition, this type of concentrated photovoltaic power generation leads to a high heat flux density on the battery surface, and the battery needs to be cooled to stabilize it within a certain temperature range. Conventional cooling methods have limited cooling capacity, and usually do not consider recycling the waste heat of photovoltaic cells, which also causes energy waste. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and provide a building energy supply system based on solar light / heat / electricity cogeneration, which can simultaneously meet the building's light, heat and electricity needs; improve the utilization efficiency of solar energy; and solve the problem of uneven temporal and spatial distribution in building energy utilization.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] The present invention proposes a building energy supply system based on solar light / heat / electricity cogeneration. The visible spectrum is used for building lighting, the infrared spectrum is used for photovoltaic cell power generation, and the photovoltaic cell is cooled by phase change working fluid so that its temperature can be stabilized within the optimal working range, while the waste heat of the cell is utilized. The system can maximize the utilization efficiency of solar energy in buildings and can fully cover the energy demand of buildings.

[0007] The present invention provides a building energy supply system based on solar light / heat / electricity cogeneration, comprising: a light-heat-electricity cogeneration unit, a lighting side, a heating side and a power supply side;

[0008] The lens at the top of the solar-heat-power cogeneration unit receives sunlight, and the solar-heat-power cogeneration unit divides the sunlight into visible light and infrared light. The visible light is directly coupled into the light guide on the lighting side to illuminate the lighting side of the building; the infrared light is used by the photovoltaic cell to generate electricity, which is transmitted to the power supply side of the building to provide electricity for the load; the heat of the photovoltaic cell is taken away by the immersion cooling medium in its enclosure structure, and transmitted to the heating side of the building to provide heat energy.

[0009] Furthermore, the lighting side includes: a building lighting load, a first light guide, a first lens, a first reflector, a homogenizer, a second lens, and a second reflector; visible light is coupled into the first light guide port and transmitted downward, and after converging into parallel light, it is irradiated on the first lens, part of the light is directly projected into the homogenizer, and after being diffused by the homogenizer, it illuminates the area inside the building, and the remaining part of the light is projected onto the first reflector due to Fresnel reflection. The second reflector is made of a total reflection material and has a non-transparent back, so that all the light is reflected to the second lens of the next floor, and part of the light is directly transmitted into the homogenizer of the underground part for illumination, and the light intensity directed to the underground part is controlled by adjusting the reflectivity of the second lens, thereby dynamically adjusting the light intensity ratio between the above-ground part and the underground part, providing lighting for the human activity area on the above-ground part, and providing more lighting for vehicles in the enclosed space of the underground part; except for the transmitted light, the remaining light is reflected toward the second reflector, and under the action of total reflection, it is projected into the homogenizer to provide lighting for the floor.

[0010] Furthermore, the power supply side includes a power storage box and a power transmission circuit. The energy in the infrared light is absorbed by the photovoltaic cell and stored in the power storage box. The power transmission circuit provides electrical energy to the building lighting loads in the above-ground and underground parts, thereby performing lighting. In the underground part, the lighting is entirely provided by the building lighting load and the first light guide tube, and the above-ground part also includes natural sunlight.

[0011] Further, the heating side includes: a cooling medium distribution unit, a first cooling medium condensation circuit, a second cooling medium condensation circuit, a hot water storage tank, a phase change material heat storage unit, a first heat exchanger, a second heat exchanger, a third heat exchanger, a water supply passage, a phase change material heat exchange circuit, a building hot water load, and a fourth heat exchanger;

[0012] The photovoltaic cells in the solar-thermal-power cogeneration unit are cooled by immersing the cooling medium, and the cooling medium is sent to the cooling medium distribution unit through the cooling medium circuit. Due to the use of the immersed cooling medium in the form of flow boiling, the cooling medium is condensed in the cooling medium distribution unit to release heat. Part of the heat is sent to the first heat exchanger by the first cooling medium condensation circuit, and the heat is transferred to the cooling water in the hot water storage tank; the other part of the heat is sent to the second heat exchanger by the second cooling medium condensation circuit, and heat is exchanged with the solid phase change material in the phase change material heat storage unit, so that the excess heat is stored in the phase change material; the hot water in the hot water storage tank directly supplies heat to the building hot water load through the water supply channel to heat the building. Due to the instability and temporal and spatial non-uniformity of solar energy heating, the high heat storage characteristics of the solid phase change material make it possible to store excess heat therein. When the conventional heating power is insufficient, heat can be extracted from the phase change material through the fourth heat exchanger, the phase change material heat exchange circuit and the third heat exchanger to supplement the building heating demand.

[0013] Furthermore, the photovoltaic, thermal and power cogeneration unit includes: a focusing lens, a cooling medium, a cooling fin, a spectrum divider, a photovoltaic cell, and a second light guide;

[0014] The full spectrum of sunlight is incident on the focusing lens, and concentrated light is obtained under the focusing effect of the focusing lens, so that the spot size can be absorbed by the spectrum divider. Under the frequency division effect of the spectrum divider at a special angle, the infrared spectrum in the AM1.5 solar spectrum on the AM1.5 side is reflected on the photovoltaic cell for power generation; the visible spectrum is transmitted and coupled into the second light guide to provide lighting for the building; the three-in-one integrated structure can improve the utilization rate of solar energy and facilitate the thermal management of photovoltaic cells; part of the infrared energy of the photovoltaic cell is used for power generation, and the other part is dissipated in the form of heat energy, a small part is absorbed by the cooling fins in the integrated structure, and the rest is absorbed by the cooling medium injected into the cavity structure surrounded by three photovoltaic cells. The cooling medium is a low-boiling-point immersion coolant. The cooling medium is in direct contact with the backplane of the photovoltaic cell, eliminating the thermal resistance generated by conventional cooling methods. At the same time, a dielectric medium needs to be selected to avoid leakage of the device. The low-boiling-point cooling medium undergoes phase change and evaporates at a low saturation temperature to take away heat. At this time, the temperature remains unchanged, which is beneficial to the temperature stability of the photovoltaic cell. The immersion cooling medium is also beneficial to the heat utilization on the heating side. Compared with air cooling, the heat exchange efficiency between fluid working media is higher. Compared with single-phase liquid cooling, its phase change process can take away more heat for building use.

[0015] Furthermore, the light receiving device includes: multiple photovoltaic cogeneration units, dust-proof film, focusing lens, solar tracker, and base; the light receiving device serves as the total energy input end of the system, integrates multiple photovoltaic cogeneration units, and provides energy for the system. When the light receiving device is working, the solar tracker is turned on to make the panel of the photovoltaic cogeneration unit follow the sun angle for dual-axis tracking to maintain the light collection efficiency of the focusing lens. At the same time, the dust-proof film is used to prevent the impact of polluted particles on the integrated unit during rain, snow or windy and sandy weather on the roof. The photovoltaic cogeneration unit is a group of three focusing lenses, which can maximize the solar energy utilization efficiency of the light receiving device.

[0016] The overall building structure here has only two floors above ground and one floor underground. To simplify the system, the principle description is sufficient to cover the operation of building systems with more floors, so the system operation principle diagram for more floors is not given.

[0017] Furthermore, a geometric model between the focusing lens, photovoltaic cell, and spectrum divider is established to obtain a configuration suitable for an integrated solar-thermal-power cogeneration unit. The specific calculation process is as follows:

[0018] Before establishing the geometric model, the following definitions are made: the photovoltaic cell is a square with negligible thickness; the photovoltaic cells are perpendicular to the three focusing lenses, and the three photovoltaic cells together form a triangular prism with an equilateral triangle as the base; the spacing between the focusing lenses is temporarily fixed at 105mm, and the focal length is fixed at 120mm; the solar flux density incident on the surface of the focusing lens is G, the energy concentration ratio is R, and the energy flux density on the photovoltaic cell is G pv . x is the distance from the photovoltaic cell to the center of the focusing lens;

[0019] According to the geometric relationship between the focusing lens and the photovoltaic cell, the relationship between the width w of the photovoltaic cell and the center distance x is derived as shown in the following formula:

[0020] w=2(52.5 / cosα-x) / tanβ(0<x<52.5 / cosα);

[0021] At this time, the relative position of the focusing lens is fixed, so the change in the center distance x is caused by the movement of the photovoltaic cell.

[0022] The relationship between the reflected light spot diameter d, the focusing lens-spectral frequency divider distance a, the distance between the two focal points b and the energy focusing ratio R can be obtained through the following relationship:

[0023] a+b=f=120mm;

[0024]

[0025] R=G PV / G;

[0026] Where f is the focal length of the condenser lens, 120 mm; df is the diameter of the condenser lens, 100 mm; G and G pv are the irradiance incident on the focusing lens and photovoltaic cell, W / m 2 ; a is the distance between the center point o of the spectrum divider and the focusing lens, mm; x is the distance between the photovoltaic cell and the center point o of the spectrum divider, mm; b is the distance from the focal point to the spectrum divider, mm (a+b=f); 0.34 is the spectral energy reflectance of the spectrum divider under AM1.5.

[0027] Furthermore, according to the calculation of the above relationship, it can be concluded that under the condition of a being determined, w, d and G pv, with the change of center distance x. When a is determined, w decreases with the increase of x; d decreases first and then increases with the increase of x; when x = b, its value is the smallest; this is because when x = b, the photovoltaic cell is located at the focus of reflection; the energy change on the photovoltaic cell is inversely proportional to the trend of the spot change, so its value increases first and then decreases with the increase of x, and when x = b, its value is the largest; from the overall comparison, when a gradually increases, the b value gradually decreases, and the focus of the reflected light is getting closer and closer to the center line.

[0028] Furthermore, since the power generation efficiency of photovoltaic cells needs to be given priority, both w and d are constantly changing with x, and when w is equal to d, the width of the photovoltaic cell is equal to the diameter of the light spot incident on its surface, and the utilization area of ​​the photovoltaic cell is the largest at this time; therefore, it is first considered that the economic performance of the light-hot spot cogeneration unit is the best when w=d; and since the lower the concentration of the photovoltaic cell, the more uniform its energy flux density, that is, the efficiency of the photovoltaic cell, decreases with the increase of the concentration ratio; therefore, a smaller concentration ratio is used, and the diameter of the beam splitter is also smaller at this time, which is conducive to reducing the equipment investment cost; in actual application, the structure of the light-hot spot cogeneration unit can be adjusted according to the ratio between the various parameters;

[0029] The parameter ratios applicable to the photothermal and thermal energy cogeneration unit are calculated.

[0030] The overall configuration of the unit when a certain parameter is determined is given here, and any easily obtainable configuration derived from this geometric model is also within the protection scope of the present invention.

[0031] Further, the building energy supply system is used to supply energy to a plant production factory, and the system also includes: a nutrient solution stirring unit, a nutrient solution cooling unit, and a nutrient solution tank, wherein the nutrient solution tank is located on the heating side;

[0032] When sunlight shines on the solar-heat-power cogeneration unit, the visible light is directly transmitted into the first light guide tube, first shines on the first lens, and part of the light is directly transmitted into the homogenizer to provide lighting for the crops. The remaining light is reflected by the Fresnel reflection to the first reflector, and after total reflection, it is directed to the second reflector on the next layer of the plant production factory. After total reflection, it is directed to the third reflector and finally enters the homogenizer to form a lighting area to provide lighting for the next layer of crops.

[0033] After the photovoltaic cell generates electricity, the waste heat generated is sent to the cooling medium distribution unit by the boiling cooling medium through the cooling medium loop. The cooling medium unit is condensed through the first cooling medium condensation loop, and the heat is transferred to the hot water storage tank through the first heat exchanger. The heat in the hot water storage tank is transferred to the nutrient solution tank through the second heat exchanger to heat the nutrient solution for sterilization. The sterilized nutrient solution flows into the nutrient solution cooling unit for cooling. After reaching a temperature suitable for crop growth, it is finally passed into the nutrient solution stirring unit. After the uniformity and activity of the nutrient solution meet the requirements, it can be used for crop cultivation. The electric energy required by the stirrer is supplied by the power supply side.

[0034] The electricity generated by the photovoltaic cells is stored in the power storage box, and is used through the power transmission circuit to provide electricity to the lighting loads on each floor of the plant production factory to supplement the lighting, as well as to provide the electricity required for the agitator and the motor.

[0035] The plant production factory is a fully enclosed structure and lacks direct lighting from the sun through the windows. Its lighting needs are particularly important. The ratio of the visible spectrum to the infrared spectrum can be adjusted according to the structural design of the solar heat and power cogeneration unit to give priority to ensuring the lighting needs. Other readily available structures generated on this basis are also within the scope of protection of the present invention.

[0036] Compared with the prior art, the present invention has the following advantages:

[0037] (1) It can simultaneously meet the building's solar, thermal and electricity needs; the efficient solar energy utilization mode of the solar, thermal and power cogeneration unit, that is, by designing a unique spectral divider angle, a specific infrared spectrum is reflected to the photovoltaic cell for power generation, and the visible spectrum is introduced into the optical fiber for lighting. At the same time, the immersion cooling fluid is used to flow and boil to directly cool the photovoltaic cell, maximize the heat removal of the cell, and utilize it to achieve solar, thermal and power cogeneration.

[0038] (2) Improve the utilization efficiency of solar energy. The efficient integrated structure of the solar thermal power cogeneration unit, with three concentrating units as a group, can maximize the area utilization of the solar receiver; the calculated three-in-one solar thermal power cogeneration unit structure, that is, the optimal geometric configuration of the concentrating lens, spectrum divider, and photovoltaic cell for this unit, can achieve the optimal light utilization and the best economic performance; the flow boiling phase change cooling method of the photovoltaic cell is conducive to the battery working in a fixed temperature range, and the flow working fluid cooling is also conducive to the utilization of waste heat, avoiding the heat loss caused by the secondary heat exchange of the solid phase change material.

[0039] (3) It can solve the problem of uneven temporal and spatial distribution of building energy utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 Schematic diagram of the solar-heat-power combined energy system for buildings;

[0041] Figure 2 This is a schematic diagram of the working principle of the solar-thermal-power cogeneration unit;

[0042] Figure 3 is a schematic diagram of a light receiving device;

[0043] Figure 4 A top view of the CHP unit;

[0044] Figure 5 It is a front view of the solar-heat-power cogeneration unit;

[0045] Figure 6 Schematic diagram of a solar-heat-power building energy supply system for plant production plants;

[0046] Figure numerals: 1. Sunlight; 2. Solar-thermal-power cogeneration unit; 3. Cooling medium circuit; 4. Cooling medium distribution unit; 5. First cooling medium condensation circuit; 6. Second cooling medium condensation circuit; 7. Hot water storage tank; 8. Phase change material heat storage unit; 9. First heat exchanger; 10. Second heat exchanger; 11. Third heat exchanger; 12. Water supply passage; 13. Phase change material heat exchange circuit; 14. Building hot water load; 15. Fourth heat exchanger; 16. Power storage box; 17. Power transmission circuit; 18. Building lighting load; 19. Light guide; 20. First lens; 21. First reflector; 22. Homogenizer; 23. Second lens; 24. Second reflector; 25. Human activity area; 26. Above-ground part; 27. Underground part ; 28. Vehicle; 29. ​​Focusing lens; 30. Cooling medium; 31. Cooling fins; 32. Converging light; 33. Spectral divider; 34. Infrared light; 35. Visible light; 36. Photovoltaic cell; 37. Light guide; 38. AM1.5 side; 39. Power generation side; 40. Lighting side; 41. AM1.5 solar spectrum; 42. Infrared spectrum; 43. Visible spectrum; 44. Light receiving device; 45. Dust-proof film; 46. Solar tracker; 48. Base; 50. Nutrient solution tank; 51. Nutrient solution cooling unit; 52. Nutrient solution stirring unit; 53. Stirrer; 54. Plant production factory; 55. Crop; 56. Illumination area; 57. Motor; 59. Heating side; 61. Third reflector. DETAILED DESCRIPTION

[0047] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. Component models, material names, connection structures, control methods, algorithms and other features not clearly described in this technical solution are all considered to be common technical features disclosed in the prior art.

[0048] Example 1

[0049] A building energy supply system based on solar light / heat / electricity cogeneration, such as Figure 1As shown, it includes: a solar-heat-power cogeneration unit 2, a lighting side 40, a heating side 59 and a power supply side 39;

[0050] The lens at the top of the solar heat and power cogeneration unit 2 receives sunlight 1, and the solar heat and power cogeneration unit 2 divides the sunlight 1 into visible light 35 and infrared light 34. The visible light 35 is directly coupled into the light guide 19 on the lighting side 40 to illuminate the lighting side 40 of the building; the infrared light 34 is used by the photovoltaic cell 36 to generate electrical energy, which is transmitted to the power supply side 39 of the building to provide electrical energy for the load; the heat of the photovoltaic cell 36 is taken away by the immersion cooling medium in its enclosure structure, and is transmitted to the heating side of the building to provide thermal energy.

[0051] In a specific embodiment, the lighting side 29 includes: a building lighting load 18, a first light pipe 19, a first lens 20, a first reflector 21, a light homogenizer 22, a second lens 23, and a second reflector 24; the visible light 35 is coupled into the port of the first light pipe 19, and is transmitted downward, converged into parallel light, and then irradiated on the first lens 20, part of the light is directly projected into the light homogenizer 22, and after being diffused by the light homogenizer 22, it illuminates the area inside the building, and the remaining part of the light is projected on the first reflector 21 due to the Fresnel reflection effect. The second reflector 21 is made of a fully reflective material, and the back is not The second lens 23 is transparent, so that all the light is reflected to the second lens 23 on the next floor, and part of the light is directly transmitted to the light homogenizer 22 of the underground part 27 for illumination. The light intensity directed to the underground part 27 is controlled by adjusting the reflectivity of the second lens 23, thereby dynamically adjusting the light intensity ratio between the above-ground part 26 and the underground part 27, providing illumination for the human activity area 25 of the above-ground part 26, and providing more illumination for the vehicles 28 in the closed space of the underground part 27; except for the transmitted light, the remaining light is reflected to the second reflector 24, and under the action of total reflection, it is incident on the light homogenizer 22 to provide illumination for the floor.

[0052] In a specific embodiment, the power supply side 39 includes a power storage box 16 and a power transmission circuit 17. The energy in the infrared light 34 is absorbed by the photovoltaic cell 36 and stored in the power storage box 16. The power transmission circuit 17 provides electrical energy to the building lighting loads 18 in the above-ground part 26 and the underground part 27, thereby performing lighting. In the underground part 27, all lighting is provided by the building lighting loads 18 and the first light guide 19, and the above-ground part 26 also includes natural sunlight.

[0053] In a specific embodiment, the heating side 30 includes: a cooling medium distribution unit 4, a first cooling medium condensation circuit 5, a second cooling medium condensation circuit 6, a hot water storage tank 7, a phase change material heat storage unit 8, a first heat exchanger 9, a second heat exchanger 10, a third heat exchanger 11, a water supply passage 12, a phase change material heat exchange circuit 13, a building hot water load 14, and a fourth heat exchanger 15;

[0054] The photovoltaic cell 9 in the solar-thermal-power cogeneration unit 2 is cooled by immersion in the cooling medium. The cooling medium is sent to the cooling medium distribution unit 4 through the cooling medium circuit 3. Due to the immersion in the cooling medium in the form of flow boiling, the cooling medium is condensed in the cooling medium distribution unit 4 and releases heat. Part of the heat is sent to the first heat exchanger 9 by the first cooling medium condensation circuit 5, and the heat is transferred to the cooling water in the hot water storage tank 7; the other part of the heat is sent to the second heat exchanger 10 by the second cooling medium condensation circuit 6, and the heat is stored in the phase change material. The solid phase change material in unit 8 exchanges heat, so that the excess heat is stored in the phase change material; the hot water in the heat storage tank 7 directly supplies the heat to the building hot water load 14 through the water supply passage 12 to heat the building. Due to the instability and spatial and temporal non-uniformity of solar energy heating, the high heat storage characteristics of the solid phase change material make it possible to store excess heat therein. When the conventional heating power is insufficient, heat can be extracted from the phase change material through the fourth heat exchanger 15, the phase change material heat exchange loop 13 and the third heat exchanger 11 to supplement the building heating demand.

[0055] In a specific embodiment, Figure 2 As shown, the solar-thermal-power cogeneration unit 2 includes: a focusing lens 29, a cooling medium 30, a cooling fin 31, a spectrum splitter 33, a photovoltaic cell 36, and a second light guide 37;

[0056] The full spectrum of sunlight 1 is incident on the focusing lens 29, and the focused light 32 is obtained under the focusing effect of the focusing lens 29, so that the spot size can be absorbed by the spectrum splitter 33. Under the frequency splitting effect of the spectrum splitter 33 at a special angle, the infrared spectrum 42 in the AM1.5 solar spectrum 41 of the AM1.5 side 38 is reflected on the photovoltaic cell 36 for power generation; the visible spectrum 43 is transmitted and coupled into the second light guide 37 to provide lighting for the building; the three-in-one integrated structure can improve the utilization rate of solar energy and facilitate the thermal management of the photovoltaic cell 36; part of the infrared energy of the photovoltaic cell 36 is used for power generation, and the other part is dissipated in the form of heat energy, a small part is absorbed by the cooling fins 31 in the integrated structure, and the remaining large part is absorbed by the cooling medium 30 injected into the cavity structure surrounded by the three photovoltaic cells 36. The cooling medium 30 is an immersion cooling liquid with a low boiling point. The cooling medium 30 is in direct contact with the back plate of the photovoltaic cell 36, eliminating the thermal resistance generated by conventional cooling methods. At the same time, a dielectric medium needs to be selected to avoid leakage of the device. The low-boiling-point cooling medium 30 undergoes phase change and evaporates at a low saturation temperature to take away heat. At this time, the temperature remains unchanged, which is beneficial to the temperature stability of the photovoltaic cell 36. The immersion cooling medium is also beneficial to the heat utilization on the heating side. Compared with air cooling, the heat exchange efficiency between fluid working media is higher. Compared with single-phase liquid cooling, its phase change process can take away more heat for building use.

[0057] In a specific embodiment, Figure 3As shown, the light receiving device 44 includes: multiple photovoltaic cogeneration units 2, dustproof film 45, condensing lens 29, solar tracker 46, and base 48; the light receiving device 44 serves as the total energy input end of the system, integrates multiple photovoltaic cogeneration units 2, and provides energy for the system. When the light receiving device 44 is working, the solar tracker 46 is turned on to make the panel of the photovoltaic cogeneration unit 2 follow the sun angle for dual-axis tracking to maintain the light collection efficiency of the condensing lens 29. At the same time, the dustproof film 45 is used to prevent the impact of polluted particles on the integrated unit during rain, snow or windy and sandy weather on the roof. The photovoltaic cogeneration unit 2 is a group of three condensing lenses 29, which can maximize the solar energy utilization efficiency of the light receiving device 1.

[0058] Here, the above-ground part 26 of the overall building structure has only two floors, and the underground part 27 has only one floor. In order to simplify the system, its principle description is sufficient to cover the operation of building systems with more floors, so the system operation principle diagram for more floors is not given.

[0059] like Figure 4 , 5 As shown, in a specific implementation, a geometric model between the focusing lens 29, the photovoltaic cell 36, and the spectrum divider 33 is established to obtain a configuration suitable for an integrated solar-thermal-power cogeneration unit. The specific calculation process is as follows:

[0060] Before establishing the geometric model, the following definitions are made: the photovoltaic cell is a square, and the thickness is negligible; the photovoltaic cells are perpendicular to the three focusing lenses 29, and the three photovoltaic cells 36 together form a triangular prism with an equilateral triangle as the base; the spacing between the focusing lenses 29 is temporarily fixed to 105mm, and the focal length is fixed to 120mm; the solar flux density incident on the surface of the focusing lens 29 is G, the energy concentration ratio is R, and the energy flux density on the photovoltaic cell 36 is G pv x is the distance from the photovoltaic cell 36 to the center of the focusing lens 29;

[0061] According to the geometric relationship between the focusing lens 29 and the photovoltaic cell 36, the relationship between the width w of the photovoltaic cell and the center distance x is derived as shown in the following formula:

[0062] w=2(52.5 / cosα-x) / tanβ(0<x<52.5 / cosα);

[0063] At this time, the relative position of the focusing lens is fixed, so the change in the center distance x is caused by the movement of the photovoltaic cell.

[0064] Figure 5 The geometric relationship of the photovoltaic cell when it is located before and after the focal point o is shown respectively. The relationship between the reflected light spot diameter d and the focusing lens-spectral frequency divider distance a, the distance between the two focal points b and the energy concentration ratio R is obtained through the following relationship:

[0065] a+b=f=120mm;

[0066]

[0067] R=G PV / G;

[0068] Where f is the focal length of the focusing lens, 120 mm; df is the diameter of the focusing lens, 100 mm; G and Gpv are the radiation intensity incident on the focusing lens and photovoltaic cell, W / m 2 ; a is the distance between the center point o of the spectrum divider and the focusing lens, mm; x is the distance between the photovoltaic cell and the center point o of the spectrum divider, mm; b is the distance from the focal point to the spectrum divider, mm (a+b=f); 0.34 is the spectral energy reflectance of the spectrum divider under AM1.5.

[0069] In a specific implementation, according to the calculation of the above relationship, it can be concluded that under the condition that a is determined, w, d and G pv , with the change of center distance x. When a is determined, w decreases with the increase of x; d decreases first and then increases with the increase of x; when x = b, its value is the smallest; this is because when x = b, the photovoltaic cell is located at the focus of reflection; the energy change on the photovoltaic cell is inversely proportional to the trend of the spot change, so its value increases first and then decreases with the increase of x, and when x = b, its value is the largest; from the overall comparison, when a gradually increases, the b value gradually decreases, and the focus of the reflected light is getting closer and closer to the center line.

[0070] In the specific implementation, since the power generation efficiency of the photovoltaic cell needs to be given priority, both w and d are constantly changing with x, and when w is equal to d, the width of the photovoltaic cell is equal to the diameter of the light spot incident on its surface, and the utilization area of ​​the photovoltaic cell is the largest at this time; so it is first considered that the economic performance of the light-hot spot cogeneration unit is the best when w=d; and since the lower the concentration of the photovoltaic cell, the more uniform its energy flow density, that is, the efficiency of the photovoltaic cell, decreases with the increase of the concentration ratio; therefore, a smaller concentration ratio is used, and the diameter of the beam splitter is also smaller at this time, which is conducive to reducing the equipment investment cost; finally, the a value is selected as 105mm; at this time, D f is 17.7mm; at this time, x=51mm, w=d=30mm; in actual application, the structure of the light-heat-point cogeneration unit can be adjusted according to the ratio between the parameters;

[0071] The parameter ratios applicable to the photothermal and thermal energy cogeneration unit are calculated.

[0072] The overall configuration of the unit when a certain parameter is determined is given here, and any easily obtainable configuration derived from this geometric model is also within the protection scope of the present invention.

[0073] Example 2

[0074] The building energy supply system is used for energy supply of plant production factory. Compared with Example 1, Figure 6 As shown, the system further includes: a nutrient solution stirring unit 52, a nutrient solution cooling unit 51, and a nutrient solution tank 50, wherein the nutrient solution tank 50 is located at the heating side 59;

[0075] Sunlight 1 shines on the solar-heat-power cogeneration unit 2, and visible light 35 is directly transmitted into the first light guide 19, first shining on the first lens 20, and part of the light is directly transmitted into the homogenizer 22 to provide lighting for the crop 55. The remaining light is reflected by the first reflector 21 under the action of Fresnel reflection, and passes to the second reflector 24 of the next layer of the plant production factory 54 after total reflection, and then shines on the third reflector 61 after total reflection, and finally shines into the homogenizer 22 to form a lighting area 56 to provide lighting for the next layer of crops 55.

[0076] After the photovoltaic cell 36 generates electricity, the waste heat generated is sent to the cooling medium distribution unit 4 by the boiling cooling medium through the cooling medium circuit 3. The cooling medium unit 4 is condensed through the first cooling medium condensation circuit 5, and the heat is transferred to the hot water storage tank 7 through the first heat exchanger 7. The heat in the hot water storage tank 7 is transferred to the nutrient solution tank 50 through the second heat exchanger 10, and the nutrient solution is heated for sterilization. The sterilized nutrient solution flows into the nutrient solution cooling unit 51 for cooling, and finally enters the nutrient solution stirring unit 52 after reaching a temperature suitable for crop growth. After the uniformity and activity of the nutrient solution meet the requirements, it can be used for crop cultivation. The electric energy required by the stirrer 53 is supplied by the power supply side 39;

[0077] The electric energy generated by the photovoltaic cell 36 is stored in the power storage box 16 , and is provided to the lighting loads on each floor of the plant production factory 54 through the power transmission circuit 17 to supplement the lighting, and to provide the electric energy required by the agitator 53 and the motor 57 .

[0078] The plant production factory is a fully enclosed structure and lacks direct lighting from the sun through the windows. Its lighting needs are particularly important. The ratio of the visible spectrum to the infrared spectrum can be adjusted according to the structural design of the solar-thermal-power cogeneration unit 2 to give priority to ensuring the lighting needs. Other readily available structures generated on this basis are also within the scope of protection of the present invention.

[0079] Components not described in detail in this embodiment are all existing components that can be purchased through public channels.

[0080] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A building energy supply system based on solar light / heat / electricity cogeneration, characterized in that: include: A solar heat and power cogeneration unit (2), a lighting side (40), a heating side (59) and a power supply side (39); The lens at the top of the solar heat and power cogeneration unit (2) receives sunlight (1), and the solar heat and power cogeneration unit (2) divides the sunlight (1) into visible light (35) and infrared light (34). The visible light (35) is directly coupled into the light guide (19) on the lighting side (40) to illuminate the lighting side (40) of the building; the infrared light (34) is used by the photovoltaic cell (36) to generate electrical energy, which is transmitted to the power supply side (39) of the building to provide electrical energy for the load; the heat of the photovoltaic cell (36) is taken away by the immersion cooling medium in its enclosure structure, and is transmitted to the heating side of the building to provide thermal energy.

2. A building energy supply system based on solar light / heat / electricity cogeneration according to claim 1, characterized in that: The lighting side (29) comprises: a building lighting load (18), a first light pipe (19), a first lens (20), a first reflector (21), a light homogenizer (22), a second lens (23), and a second reflector (24); the visible light (35) is coupled into the port of the first light pipe (19), and is transmitted downward, converged into parallel light, and then irradiated on the first lens (20); part of the light is directly projected into the light homogenizer (22), and after being diffused by the light homogenizer (22), it illuminates the area inside the building; the remaining part of the light is projected onto the first reflector (21) due to the Fresnel reflection effect, and the second reflector (21) makes all the light The light is reflected to the second lens (23) of the next floor, and part of the light is directly transmitted to the light homogenizer (22) of the underground part (27) for illumination. The light intensity directed to the underground part (27) is controlled by adjusting the reflectivity of the second lens (23), thereby dynamically adjusting the light intensity ratio between the above-ground part (26) and the underground part (27), providing illumination for the human activity area (25) of the above-ground part (26), and providing more illumination for the vehicles (28) in the closed space of the underground part (27). In addition to the transmitted light, the remaining light is reflected to the second reflector (24), and under the action of total reflection, it is incident on the light homogenizer (22) to provide illumination for the floor.

3. A building energy supply system based on solar light / heat / electricity cogeneration according to claim 1, characterized in that: The power supply side (39) includes a power storage box (16) and a power transmission circuit (17). The energy in the infrared light (34) is absorbed by the photovoltaic cell (36) and stored in the power storage box (16). The power transmission circuit (17) provides electric energy to the building lighting load (18) in the above-ground part (26) and the underground part (27), thereby providing lighting. In the underground part (27), the lighting is entirely provided by the building lighting load (18) and the first light guide (19), and the above-ground part (26) also includes natural sunlight.

4. A building energy supply system based on solar light / heat / electricity cogeneration according to claim 1, characterized in that: The heating side (30) comprises: a cooling medium distribution unit (4), a first cooling medium condensation circuit (5), a second cooling medium condensation circuit (6), a hot water storage tank (7), a phase change material heat storage unit (8), a first heat exchanger (9), a second heat exchanger (10), a third heat exchanger (11), a water supply passage (12), a phase change material heat exchange circuit (13), a building hot water load (14), and a fourth heat exchanger (15); The photovoltaic cell (9) in the solar-heat-power cogeneration unit (2) is cooled by immersion in a cooling medium. The cooling medium is sent to a cooling medium distribution unit (4) through a cooling medium circuit (3). Due to the use of a flow boiling type immersion cooling medium, the cooling medium is condensed in the cooling medium distribution unit (4) and releases heat. Part of the heat is sent to a first heat exchanger (9) by a first cooling medium condensation circuit (5) to transfer the heat to cooling water in a hot water storage tank (7); the other part of the heat is sent to a second cooling medium condensation circuit (5) to transfer the heat to cooling water in a hot water storage tank (7). The condensation loop (6) is sent to the second heat exchanger (10) to exchange heat with the solid phase change material in the phase change material heat storage unit (8), so that excess heat is stored in the phase change material; the hot water in the hot water storage tank (7) directly supplies heat to the building hot water load (14) through the water supply passage (12) to heat the building. When the conventional heating power is insufficient, heat can be extracted from the phase change material through the fourth heat exchanger (15), the phase change material heat exchange loop (13) and the third heat exchanger (11) to supplement the heating demand of the building.

5. The building energy supply system based on solar light / heat / electricity cogeneration according to claim 1 is characterized in that: The photovoltaic, thermal and power cogeneration unit (2) comprises: a focusing lens (29), a cooling medium (30), cooling fins (31), a spectrum splitter (33), a photovoltaic cell (36), and a second light guide (37); The full spectrum of sunlight (1) is incident on a focusing lens (29), and under the focusing effect of the focusing lens (29), a focused light (32) is obtained, so that the light spot size can be absorbed by a spectrum frequency splitter (33). Under the frequency splitting effect of the spectrum frequency splitter (33), an infrared spectrum (42) in an AM1.5 solar spectrum (41) on the AM1.5 side (38) is reflected on a photovoltaic cell (36) for power generation; the visible spectrum (43) is transmitted and coupled into a second light guide (37) to provide lighting for the building; a part of the infrared energy of the photovoltaic cell (36) is used for power generation, and another part is dissipated in the form of heat energy, a small part is absorbed by a cooling fin (31) in the integrated structure, and the remaining large part is absorbed by a cooling medium (30) injected into a cavity structure surrounded by three photovoltaic cells (36).

6. A building energy supply system based on solar light / heat / electricity cogeneration according to claim 1, characterized in that: The light receiving device (44) comprises: a plurality of photovoltaic cogeneration units (2), a dustproof film (45), a focusing lens (29), a solar tracker (46), and a base (48); when the light receiving device (44) is working, the solar tracker (46) is turned on, so that the panels of the photovoltaic cogeneration units (2) follow the angle of the sun to perform dual-axis tracking to maintain the light collection efficiency of the focusing lens (29); at the same time, the dustproof film (45) is used to prevent the impact of polluted particles on the integrated unit during rain, snow or windy and sandy weather on the roof.

7. A building energy supply system based on solar light / heat / electricity cogeneration according to claim 1, characterized in that: A geometric model between the focusing lens (29), the photovoltaic cell (36), and the spectrum divider (33) is established to obtain a configuration suitable for an integrated solar-thermal-power cogeneration unit. The specific calculation process is as follows: Before establishing the geometric model, the following definitions are made: the photovoltaic cell is a square, and the thickness is negligible; the photovoltaic cells are perpendicular to the three focusing lenses (29), and the three photovoltaic cells (36) together form a triangular prism with an equilateral triangle as the base; the spacing between the focusing lenses (29) is temporarily fixed at 105 mm, and the focal length is fixed at 120 mm; the solar flux density incident on the surface of the focusing lens (29) is G, the energy concentration ratio is R, the energy flux density on the photovoltaic cell (36) is Gpv, and x is the distance from the photovoltaic cell (36) to the center of the focusing lens (29); According to the geometric relationship between the focusing lens (29) and the photovoltaic cell (36), the relationship between the width w of the photovoltaic cell and the center distance x is derived as shown in the following formula: w=2(52.5 / cosα-x) / tanβ(0<x<52.5 / cosα); The relationship between the reflected light spot diameter d, the focusing lens-spectral frequency divider distance a, the distance between the two focal points b and the energy focusing ratio R can be obtained through the following relationship: a+b=f=120mm; R=G PV / G; Where f is the focal length of the condenser lens, 120 mm; df is the diameter of the condenser lens, 100 mm; G and G pv are the radiation intensities incident on the focusing lens and the photovoltaic cell, W / m2; a is the distance between the center point o of the spectrum divider and the focusing lens, mm; x is the distance between the photovoltaic cell and the center point o of the spectrum divider, mm; b is the distance from the focal point to the spectrum divider, mm (a+b=f); 0.34 is the spectral energy reflectance of the spectrum divider under AM1.

5.

8. A building energy supply system based on solar light / heat / electricity cogeneration according to claim 7, characterized in that: When a is determined, w decreases continuously with the increase of x; d decreases first and then increases with the increase of x; when x=b, its value is the smallest; this is because when x=b, the photovoltaic cell is located at the reflection focus; the energy change on the photovoltaic cell is inversely proportional to the trend of the light spot change, so its value first increases and then decreases with the increase of x, and when x=b, its value is the largest; from the overall comparison, when a gradually increases, the b value gradually decreases, and the focus of the reflected light gets closer and closer to the center line.

9. A building energy supply system based on solar light / heat / electricity cogeneration according to claim 7, characterized in that: Since the power generation efficiency of photovoltaic cells needs to be given priority, w and d are constantly changing with x, and when w is equal to d, the width of the photovoltaic cell is equal to the diameter of the light spot incident on its surface, and the utilization area of ​​the photovoltaic cell is the largest at this time; so it is first considered that the economic performance of the light-hot spot cogeneration unit is the best when w=d; and because the lower the concentration of the photovoltaic cell, the more uniform its energy flux density, that is, the efficiency of the photovoltaic cell, decreases with the increase of the concentration ratio; therefore, a smaller concentration ratio is used, and the diameter of the beam splitter is also smaller at this time, which is conducive to reducing the equipment investment cost; in actual application, the structure of the light-hot spot cogeneration unit can be adjusted according to the ratio between the various parameters; The parameter ratios applicable to the photothermal and thermal energy cogeneration unit are calculated.

10. A building energy supply system based on solar light / heat / electricity cogeneration according to claim 1, characterized in that: The building energy supply system is used for supplying energy to a plant production factory, and the system further comprises: a nutrient solution stirring unit (52), a nutrient solution cooling unit (51), and a nutrient solution tank (50), wherein the nutrient solution tank (50) is located on the heating side (59); Sunlight (1) irradiates the solar heat and power cogeneration unit (2), and visible light (35) is directly transmitted into the first light guide (19), first irradiates the first lens (20), and part of the light is directly transmitted into the light homogenizer (22) to provide lighting for the crop (55), and the remaining light is emitted to the first reflector (21) under the action of Fresnel reflection, and passes to the second reflector (24) of the next layer of the plant production factory (54) after total reflection, and then emitted to the third reflector (61) after total reflection, and finally emitted into the light homogenizer (22), forming a lighting area (56), and providing lighting for the next layer of crops (55); After the photovoltaic cell (36) generates electricity, the waste heat generated is sent to the cooling medium distribution unit (4) by the boiling cooling medium through the cooling medium circuit (3). The cooling medium unit (4) is condensed through the first cooling medium condensation circuit (5), and the heat is transferred to the hot water storage tank (7) through the first heat exchanger (7). The heat in the hot water storage tank (7) is transferred to the nutrient solution tank (50) through the second heat exchanger (10), and the nutrient solution is heated for sterilization. The sterilized nutrient solution flows into the nutrient solution cooling unit (51) for cooling. After reaching a temperature suitable for crop growth, it is finally passed into the nutrient solution stirring unit (52). After the uniformity and activity of the nutrient solution meet the requirements, it can be used for crop cultivation. The electric energy required by the stirrer (53) is supplied by the power supply side (39); The electric energy generated by the photovoltaic cell (36) is stored in the power storage box (16), and is provided to the lighting loads on each floor of the plant production factory (54) through the power transmission circuit (17) to supplement the lighting, and to provide the electric energy required by the agitator (53) and the motor (57).

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