Multifunctional passive photovoltaic photo-thermal building integrated system

Abstract

The utility model relates to a multifunctional passive photovoltaic photo-thermal building integrated system which comprises a house body, and a sunny side, a nightside and a roof of the house body are respectively provided with a double-layer structure so that communicated cavities can be formed in the sunny side, the roof and the nightside. A first ventilation opening communicated with the outside is formed in the lower portion of the outer wall of the sunny side, a second ventilation opening communicated with the interior is formed in the lower portion of the inner wall of the sunny side, a third ventilation opening communicated with the interior is formed in the lower portion of the inner wall of the nightside, and a fourth ventilation opening communicated with the outside is formed in the upper portion of the outer wall of the nightside. A chimney-shaped structure communicated with the cavity is arranged above the cavity located on the nightside, a fifth ventilation opening communicated with the outside is formed in the top of the chimney-shaped structure, baffles are arranged at the first ventilation opening to the fifth ventilation opening, and airflow is allowed to pass when the baffles are opened. The system can achieve the functions of indoor heating, heat preservation, ventilation, cooling and the like of a building.

Description

Technical Field

[0001] This utility model relates to a multifunctional passive photovoltaic-thermal building integrated system. Background Technology

[0002] The photoelectric conversion efficiency of photovoltaic panels is relatively low. Currently, the photoelectric conversion efficiency of commercially available photovoltaic panels is around 15%-25%. This means that most of the solar energy absorbed by photovoltaic panels is converted into heat energy and wasted. If this waste heat can be utilized, firstly, the overall utilization rate of solar energy can be improved, and secondly, the power generation efficiency of photovoltaic panels can also be improved, because the power generation efficiency of photovoltaic panels decreases as the temperature rises.

[0003] The practice of integrating solar photovoltaic (PV) power generation facilities with buildings is called BIPV (building-integrated photovoltaic) system. Unlike the previous BAPV (battery-integrated photovoltaic) approach, which simply involved installing photovoltaic panels on buildings, BIPV integrates the photovoltaic system (PV) more closely with the building, treating it as part of the structure and enabling functions beyond power generation. If the function involves heat application, it can be called a BIPV / T (T stands for thermal, i.e., integrated photovoltaic and solar thermal system) system.

[0004] Patent CN 109869852 B discloses a passive BIPV / T system for chicken coops. According to its patent drawings, it utilizes a thermal storage wall as one side and glass and photovoltaic panels as the other to form a solar chimney. With baffles installed above and below the sun-facing wall, it exhausts air outwards for ventilation in summer and inwards for heating in winter. A fresh air supply device providing cooling is installed on the north-facing wall, and heat pipes are installed on the sun-facing thermal storage wall and roof to enhance heat transfer. While this patent claims to provide warmth in winter and coolness in summer, careful analysis reveals significant shortcomings in its system design: 1. During winter heating, the hot air outlet is located at the top, easily creating a temperature stratification effect—the upper air is very hot while the lower air is not heated, thus failing to provide warmth for the chickens. The applicant has verified this using simulation software. 2. The heat pipe arrangement may not be effective and could exacerbate air temperature stratification.

[0005] Patent CN 114234334 A discloses a system for regulating indoor air temperature using buried pipes. According to the accompanying drawings, a photovoltaic collector placed on the roof heats the air, which is then exhausted through a chimney, drawing in fresh air through the buried pipes. In summer, due to the low soil temperature, cool air is drawn in; in winter, due to the high soil temperature, warm air is drawn in. While this patent can utilize the constant temperature layer of the soil to provide hot and cold air, it has several drawbacks: 1. It requires a specific burial depth for the buried pipes (they must be buried within the constant temperature layer), making construction and maintenance difficult (prone to water ingress, blockages, corrosion, etc.). 2. It is ineffective for situations requiring nighttime insulation, meaning it cannot operate in a closed mode. 3. There is a potential problem of rainwater entering the room.

[0006] Patent CN 110529915 A describes a system combining photovoltaic-powered electric floor heating with BIPV / T (Building Integrated Photovoltaics / Tunneling). According to the patent drawings, the BIPV / T system, installed on the sun-facing side, generates hot air, and the electricity it produces can heat the floor, thus better heating the entire indoor environment. However, this system lacks outward ventilation. Although the patent considers floor heating, the absence of ventilation and cooling functions renders it unusable in summer.

[0007] In general, these patents essentially use photovoltaic panels as heating elements to form a type of solar chimney, which, together with other equipment, constitutes a BIPV / T system that can be used for indoor HVAC. They mainly utilize only the sun-facing side of the building (i.e., the south facade or roof), which is a natural choice since photovoltaic power generation requires sunlight. However, the inventor believes that the shady side of the building, i.e., the north facade, can also be utilized as a component of the BIPV / T system (in the attached drawings of patent CN 109869852 B, although a fresh air device is installed on the north side, this device uses groundwater to cool the air and can be considered an independent device, not necessarily installed on the north side or a wall). Utility Model Content

[0008] The purpose of this utility model is to provide a multifunctional passive photovoltaic-thermal building integrated system, which can realize functions such as heating, heat preservation, ventilation and cooling of the building interior.

[0009] The technical solution of this utility model is as follows: a multifunctional passive photovoltaic and solar thermal building integrated system, including a building body, wherein the sun-facing side, the shady side, and the roof of the building body are all provided with a double-layer structure, so that the sun-facing side, the roof, and the shady side form a connected cavity. The lower part of the outer wall of the sun-facing side is provided with a first ventilation opening connected to the outside, the lower part of the inner wall of the sun-facing side is provided with a second ventilation opening connected to the interior, the lower part of the inner wall of the shady side is provided with a third ventilation opening connected to the interior, the upper part of the outer wall of the shady side is provided with a fourth ventilation opening connected to the outside, and a chimney-shaped structure connected to the cavity is provided above the cavity on the shady side. The top of the chimney-shaped structure is provided with a fifth ventilation opening connected to the outside. Baffles are provided at the first to the fifth ventilation openings, and airflow is allowed to pass through when the baffles are open.

[0010] Furthermore, the upper structure of the sun-facing exterior wall and roof is composed of solar photovoltaic panels, while the lower structure of the sun-facing interior wall, the shady interior wall, and the roof is made of thin metal sheets.

[0011] Furthermore, the back of the solar photovoltaic panel is painted, and the side of the inner wall and the lower structure of the roof facing the solar photovoltaic panel and the side of the inner wall facing the interior on the shady side are also painted.

[0012] Furthermore, the interior walls and the lower structure of the roof facing the sun, as well as the exterior walls facing the cavity, are all provided with heat-insulating coatings.

[0013] Furthermore, the distance between the inner wall and the outer wall on the sunny and shady sides is between 50-150mm.

[0014] Furthermore, when the baffle at the fourth vent is fully opened and in a horizontal position, it can prevent the cavity on the shady side from communicating with the cavity in the roof.

[0015] Furthermore, insect-proof nets are installed at the first to fifth ventilation openings.

[0016] Furthermore, a spraying device capable of spraying water onto the interior wall on the shady side is provided at the fourth ventilation opening.

[0017] Furthermore, the chimney-shaped structure extends upward and protrudes from the roof, and the sun-facing side of the chimney-shaped structure is painted or equipped with solar photovoltaic panels.

[0018] Furthermore, the solar photovoltaic panels are laid horizontally to form the upper structure of the roof; or the solar photovoltaic panels are laid at an angle to form the upper structure of the roof; and a portion of the sun-facing and shady side of the building body is configured as a double-layer structure connected to the cavity of the roof.

[0019] Compared with the prior art, the present invention has the following advantages:

[0020] 1. As is well known, hot air rises and cold air sinks, creating natural convection. This system, through its building structure design, eliminates the need for any mechanical ventilation devices, utilizing only the waste heat from photovoltaic panels to generate natural convection. It can achieve functions such as heating, insulation, ventilation, and cooling of the building's interior, reducing energy consumption for building HVAC (heat, ventilation, and air conditioning). Simultaneously, the photovoltaic panels can also generate electricity, making it a novel solution for constructing green buildings.

[0021] 2. This system proposes a passive BIPV / T system using air as the working medium. This system utilizes waste heat from the photovoltaic panels to generate natural convection for multiple functions. As is well known, hot air rises due to density changes, producing the so-called Stark effect; this principle is used in the design of solar chimneys.

[0022] 3. This system designs the north-facing wall (the side facing away from the sun) as a double-layered structure, creating a cavity that can be selectively connected to the south-facing wall and the roof cavity. Ventilation openings and sprinkler systems are installed on the upper and lower parts of this cavity. This design allows for natural convection within the room without the need for any mechanical ventilation, resulting in a more uniform temperature distribution from top to bottom, thus significantly improving the problem of temperature stratification.

[0023] 4. Furthermore, the system features six operating modes. In winter, it can function as a closed heating system, a semi-open heating system (providing fresh air), or a completely closed insulation system. In summer, it can provide simple ventilation or cooling ventilation. In other seasons, it can only cool the PV units, thereby enhancing their power generation capacity. Therefore, this system is suitable for all seasons, greatly expanding the application scenarios of passive BIPV / T systems and providing a new solution for promoting the installation and development of distributed photovoltaics. Attached Figure Description

[0024] Figure 1 This is a simplified diagram of the system structure of this utility model;

[0025] Figure 2 This is a photovoltaic layout diagram for a sloping roof according to this utility model;

[0026] Figure 3 This is a perspective view of a house with a double-layer structure according to this utility model;

[0027] Figure 4 This is a simplified structural diagram of the solar chimney of this utility model;

[0028] In the diagram: 1-Sunny side 11-Outer wall of the sunny side 12-Inner wall of the sunny side 13-First baffle 14-Second baffle 2-Shaded side 21-Inner wall of the shaded side 22-Outer wall of the shaded side 23-Third baffle 24-Fourth baffle 3-Roof 31-Upper structure of the roof 32-Lower structure of the roof 4-Cavity 5-Chimney-shaped structure 51-Fifth baffle 6-Double-layer structure. Detailed Implementation

[0029] To make the above-mentioned features and advantages of this utility model more easily understood, specific embodiments are described below in conjunction with the accompanying drawings, but this utility model is not limited thereto.

[0030] refer to Figures 1 to 4

[0031] A multifunctional passive photovoltaic-thermal building integrated system includes a building body. The sun-facing side 1 (south side), the shady side 2 (north side), and the roof 3 of the building body are all provided with a double-layer structure 6 to form a cavity. The sun-facing and shady sides are closed to the sides of the roof, thus forming a connected cavity 4 within the sun-facing side, the roof, and the shady side. A first ventilation opening communicating with the outside is provided at the lower part of the outer wall 11 of the sun-facing side; a second ventilation opening communicating with the interior is provided at the lower part of the inner wall 12 of the sun-facing side; a third ventilation opening communicating with the interior is provided at the lower part of the inner wall 21 of the shady side; a fourth ventilation opening communicating with the outside is provided at the upper part of the outer wall 22 of the shady side; and a chimney-like structure 5 communicating with the cavity is provided above the cavity on the shady side. A fifth ventilation opening communicating with the outside is provided at the top of the chimney-like structure. Each of the first to fifth ventilation openings is equipped with a baffle. When the baffle is open, airflow is allowed to pass through. Specifically, a first baffle 13, a second baffle 14, a third baffle 23, a fourth baffle 24, and a fifth baffle 51 are provided.

[0032] In this embodiment, the outer wall and the upper structure 31 of the roof on the sun-facing side are both made of solar photovoltaic panels. The method of their construction has been discussed in multiple patents and published literature (e.g., laying the solar cells on a thin metal plate, applying thermally conductive silicone between the solar cells and the thin plate, etc.).

[0033] In this embodiment, the inner wall on the sunny side, the inner wall on the shady side, and the lower structure 32 of the roof are all made of thin metal sheets (such as aluminum or steel sheets).

[0034] In this embodiment, the back of the solar photovoltaic panel is painted to enhance its heat radiation capacity. Correspondingly, the side of the interior wall and the lower structure of the roof facing the solar photovoltaic panel on the sun-facing side is painted to enhance their ability to receive heat radiation. The side of the interior wall and the lower structure of the roof facing the interior on the sun-facing side is provided with a heat-insulating coating to prevent or reduce heat transfer into the building from these two locations. Conversely, the side of the interior wall facing the interior on the shady side is painted to increase heat radiation into the building; the side of the exterior wall facing the cavity on the shady side is provided with a heat-insulating coating to reduce heat transfer to the outside.

[0035] In this embodiment, the distance between the inner wall and the outer wall on the sunny and shady sides is between 50-150mm.

[0036] In this embodiment, when the fourth baffle at the fourth vent is fully opened and in a horizontal position, it can prevent the cavity on the shady side from communicating with the cavity in the roof.

[0037] In this embodiment, insect-proof nets are installed at the first to fifth ventilation openings to block mosquitoes.

[0038] In this embodiment, the fourth ventilation opening is equipped with a spray device that can spray water onto the interior wall on the shady side for cooling purposes.

[0039] In this embodiment, the chimney-shaped structure extends upward and protrudes from the roof, and the sun-facing side of the chimney-shaped structure is painted or equipped with solar photovoltaic panels. The back side of the chimney-shaped structure, which is the shady side, extends upward and is consistent with the shady side exterior wall.

[0040] One side of the chimney-like structure is heated by sunlight (this side can be the sun-facing side or the side that absorbs sunlight after it passes through glass, such as a black-painted metal plate). The heat it releases heats the air in the cavity, and the hot air rises and flows out through the fifth vent. The bottom inlet of the chimney-like structure draws in fresh air due to negative pressure. Installing it on a building allows for indoor ventilation.

[0041] In this embodiment, the roof is horizontal, and the solar photovoltaic panels are laid horizontally to form the upper structure of the roof, see... Figure 1 Or, if the roof is sloping, the solar photovoltaic panels are laid at an angle to form the upper structure of the roof, see [reference needed]. Figure 2 .

[0042] In practice, only certain areas of the sun-facing and shady sides of the building may be constructed as a double-layered structure connected to the roof cavity. (See...) Figure 3 .

[0043] This system has six operating modes: closed heating mode, semi-open heating mode, closed insulation mode, ventilation mode, ventilation cooling mode, and photovoltaic panel simple ventilation mode. The operating principles of each mode will be explained below.

[0044] 1. Closed heating mode

[0045] This mode is suitable for cold but sunny days. When using this mode, the first, fourth, and fifth baffles must be closed, the second and third baffles opened, and all indoor windows closed. At this time, the solar photovoltaic panels on the south side and roof absorb sunlight and heat up, thus heating the air in the cavities on the south side and roof. The north-facing cavity, being shaded, will have a lower air temperature than the south-facing and roof cavities. Basic physics tells us that because the air temperature in the south-facing cavity is higher than in the north, the air density in the south-facing cavity will be lower than that in the north. This results in lower air pressure at the south-facing inner opening (second vent) and higher pressure at the north-facing inner opening (third vent). Therefore, indoor air will flow out from the north-facing inner opening (third vent) and flow into the cavity from the south-facing inner opening (second vent). This mode can continue to operate as long as the air temperature in the south-facing cavity remains higher. This model operates on a principle similar to that of a solar water heater. Because the water temperature on the sun-facing side of the absorber plate (pipe) is always higher than on the shaded side, a solar water heater can continuously heat the water in the tank without the need for mechanical or electric actuators, utilizing the principle that hot water rises and cold water sinks. It should be further noted that: First, because the outlet on the north-facing inner wall is at the bottom of the design, the hot air coming out will naturally form convection with the cold indoor air. Therefore, the indoor air temperature distribution produced by this design is much more uniform from top to bottom than in all other designs where the hot air outlet is at the top, as confirmed by simulation experiments. Second, because the north-facing inner wall has the ability to enhance heat radiation into the room, it can transfer some heat to the ground through thermal radiation, thereby increasing the temperature of the ground and the air near the ground.

[0046] 2. Semi-open heating mode

[0047] This mode is suitable for situations with strong sunlight and a need for fresh indoor air. Its operating principle is similar to Mode 1. To use this mode, the first and third baffles must be opened, the second, fourth, and fifth baffles closed, and indoor windows opened (e.g., windows on the east and west walls, or windows on the north and south walls in areas without double-walled sections). Fresh outside air enters the cavity through the south vent (first vent), is heated within the cavity, and then enters the room through the north vent (third vent). Because the windows are positioned high, the hot air naturally escapes through them, thus continuously drawing in fresh air and achieving both ventilation and air heating.

[0048] 3. Closed insulation mode

[0049] This mode is suitable for cold seasons and situations with weak sunlight, such as winter nights. In such cases, the room may have to rely on other equipment for heating. To reduce heat loss through the walls (which is usually the main factor in heat loss), all the vents of the system can be closed, creating a cavity between the walls without airflow. This utilizes the low thermal conductivity of air to achieve insulation.

[0050] 4. Ventilation Mode

[0051] This mode is suitable for situations where sunlight is strong but outside wind is weak, requiring indoor ventilation. In this case, the second, third, fourth, and fifth baffles can be opened, and all windows closed (note that, as mentioned earlier, fully opening the fourth baffle will block the connection between the north-facing cavity and the roof cavity). Due to the heating of the air by the south-facing cavity and the roof cavity, fresh air will enter the north-facing cavity from the north outer opening (fourth vent) and enter the room from the north inner opening (third vent). Meanwhile, indoor air will be drawn in from the south inner opening (second vent) and exhausted through the top opening of the roof chimney structure (fifth vent), thus achieving indoor ventilation.

[0052] 5. Ventilation and cooling mode

[0053] This mode is an upgrade from Mode 4 and is suitable for situations where indoor ventilation and cooling are both necessary, such as during hot summer days. When air enters from the north vent, the sprinkler system can spray water into the north-facing cavity. There are two scenarios: First, if the air humidity is low, the air temperature will decrease due to the evaporation and cooling of the mist droplets. Second, if the air humidity is high, or for comfort reasons, cold water can be sprayed onto the inner walls of the cavity, cooling the air as it comes into contact with the walls. The cooled air then enters the room through the north-facing inner vent (third vent), mixes with the indoor air, lowers the indoor temperature, and is then drawn into the south-facing cavity through the south-facing inner vent (second vent), finally exiting through the roof vent (fifth vent), just like in Mode 4.

[0054] 6. Solar panel ventilation mode

[0055] When there is no need for heating, insulation, ventilation, or cooling indoors, all the vents on the south side and roof can be opened. Air enters from the bottom vent (first vent), carries away the heat from the photovoltaic panels, and is then exhausted from the top of the chimney (fifth vent). This method reduces the temperature of the photovoltaic panels, thereby improving their power generation efficiency.

[0056] As explained above, although both are passive BIPV / T systems, this system differs significantly from existing solutions. The biggest difference lies in its full consideration of the potential of the building's north wall. This is something currently overlooked by all BIPV / T solutions. As mentioned earlier, patent CN 109869852 B places the cooling air generation component on the north side, but this is not essential. In other words, as long as cooling air can be generated, its location is acceptable. Regarding the crucial aspect of how to generate cooling air, this patent merely states that groundwater cooling can be used, which is insufficient. Based on these considerations, we believe the most critical point of this system proposal is the discovery of the utilization value of the building's north wall, advancing the integration of the BIPVT system with the building structure and further integrating the system into an "organic whole."

[0057] In addition, our detailed arrangements of the system are also key points. For example: 1. We require insulation of the south-facing and roof-facing lower structures. The reason is that if heat conduction in these areas is not reduced, while it is beneficial for heating the room in winter, it has a significant negative impact on cooling the room in summer. This is because the roof and sun-facing walls are often the main sources of heat in the room during summer, leading to conflicts between the various uses of the system. In our design, since heat is guided to the north side, which is not directly exposed to sunlight in summer, increasing the north side's heat radiation capacity into the room has no negative impact in summer and is actually beneficial for heating the room in winter. 2. The layout of each ventilation opening and the arrangement of the baffle opening and closing. 3. The air gap thickness of the cavity is between 50-150mm; too small or too large a thickness is not conducive to the operation of certain functions. 4. Sprinkler devices are installed at the upper ventilation openings on the north side, instead of directly spraying the indoor air.

[0058] If the terms "first" and "second" are used in the above description to define the components, those skilled in the art should know that the use of "first" and "second" is only for the convenience of distinguishing the components in the description. Unless otherwise stated, the above terms have no special meaning.

[0059] If this utility model discloses or relates to mutually fixedly connected parts or structural components, then unless otherwise stated, a fixed connection can be understood as: a detachable fixed connection (e.g., using bolts or screws) or a non-detachable fixed connection (e.g., riveting or welding). Of course, mutually fixed connections can also be replaced by an integral structure (e.g., manufactured using a casting process) (except where it is obviously impossible to use an integral forming process).

[0060] In addition, unless otherwise stated, the terms used to indicate positional relationships or shapes in any of the technical solutions disclosed in this utility model above include states or shapes that are similar to, close to, or approximate with them.

[0061] Any component provided by this utility model can be assembled from multiple individual components, or it can be a single component manufactured by a one-piece molding process.

[0062] The above description is only a preferred embodiment of the present utility model. All equivalent changes and modifications made within the scope of the patent application of the present utility model shall be covered by the present utility model.

Claims

1. A multifunctional passive photovoltaic-photothermal building integrated system, comprising a house body, characterized in that, The sun-facing side and the sun-shading side of the house body and the roof are provided with double-layer structures, so that the sun-facing side, the roof and the sun-shading side form a cavity in communication, the outer wall of the sun-facing side is provided with a first ventilation opening in communication with the outside, the inner wall of the sun-facing side is provided with a second ventilation opening in communication with the indoor, the inner wall of the sun-shading side is provided with a third ventilation opening in communication with the indoor, the outer wall of the sun-shading side is provided with a fourth ventilation opening in communication with the outside, a chimney-shaped structure is arranged above the cavity of the sun-shading side and in communication with the cavity, the chimney-shaped structure is provided with a fifth ventilation opening in communication with the outside at the top, and the first ventilation opening to the fifth ventilation opening are provided with baffles, which allow airflow when opened.

2. The multifunctional passive-type photovoltaic and photothermal building integrated system according to claim 1, characterized in that, The upper structure of the outer wall of the sun-facing side and the roof is composed of solar photovoltaic cell panels, and the inner wall of the sun-facing side, the inner wall of the sun-shading side and the lower structure of the roof are made of metal sheets.

3. The multifunctional passive-type photovoltaic and photothermal building integrated system according to claim 2, characterized in that, The back of the solar photovoltaic cell panel is colored, and the side of the inner wall of the sun-facing side and the lower structure of the roof facing the solar photovoltaic cell panel and the side of the inner wall of the sun-shading side facing the indoor are colored.

4. The multifunctional passive-type photovoltaic and photothermal building integrated system according to claim 2 or 3, characterized in that, The side of the inner wall of the sun-facing side and the lower structure of the roof facing the indoor and the side of the outer wall of the sun-shading side facing the cavity are provided with a heat insulation coating.

5. The multi-functional, passive, photovoltaic, photo-thermal, building integrated system of claim 1, 2 or 3, wherein, The distance between the inner wall and the outer wall of the sun-facing side and the sun-shading side is between 50-150mm.

6. The multi-functional, passive, photovoltaic and photothermal building integrated system according to claim 1, wherein, When the baffle at the fourth ventilation opening is fully opened and in a horizontal position, it can block the communication between the cavity of the sun-shading side and the cavity of the roof.

7. The multi-functional, passive, photovoltaic, photo-thermal, building integrated system of claim 1, 2, 3 or 6, wherein, A spraying device is arranged at the fourth ventilation opening, which can spray the inner wall of the sun-shading side.

8. The multi-functional, passive, photovoltaic, photo-thermal, building integrated system of claim 1, 2, 3 or 6, wherein, An insect screen is arranged at the first ventilation opening to the fifth ventilation opening.

9. The multi-functional, passive, photovoltaic, photo-thermal, building integrated system of claim 1, 2, 3 or 6, wherein, The chimney-shaped structure extends upward and protrudes from the roof, and the sun-facing side of the chimney-shaped structure is colored or provided with solar photovoltaic cell panels.

10. The multi-functional, passive, photovoltaic and photothermal building integrated system according to claim 2 or 3, characterized in that, The solar photovoltaic cell panels are horizontally laid to form the upper structure of the roof, or the solar photovoltaic cell panels are inclined to form the upper structure of the roof, and part of the sun-facing side and the sun-shading side of the house body is provided with a double-layer structure in communication with the cavity of the roof.

Images