Photovoltaic roof and photovoltaic curtain wall integrated ventilation and heat exchange system and design method

Abstract

The invention relates to an integrated ventilation and heat exchange system of a photovoltaic roof and a photovoltaic curtain wall and a design method, and belongs to the technical field of ventilation and heat exchange, the system is characterized in that an adjustable steel support is arranged in a photovoltaic roof area, an adjustable ventilation opening is formed in a photovoltaic curtain wall area, and a curtain wall cavity is formed between a photovoltaic curtain wall assembly and a wall body; wherein the adjustable steel bracket adjusts the thickness of the roof ventilation cavity according to the length and inclination angle of a photovoltaic array, and the adjustable ventilation opening optimizes the height of the ventilation opening according to the height and orientation of a curtain wall. When the system monitors that the temperature of the back face of the photovoltaic roof assembly or the back face of the photovoltaic curtain wall assembly or the indoor temperature is too high through a temperature sensor, active ventilation of a roof ventilation cavity and a curtain wall cavity is achieved by driving a cooling fan and adjusting the opening degree of a ventilation opening; the active ventilation can timely discharge the heat in the cavity, effectively reduces the temperature of the roof ventilation cavity and the curtain wall cavity, further reduces the working temperature of the photovoltaic module, finally prolongs the service life of the photovoltaic module, and improves the photoelectric conversion efficiency of the photovoltaic module.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ventilation and heat exchange, in particular to an integrated ventilation and heat exchange system of a photovoltaic roof and a photovoltaic curtain wall and a design method. BACKGROUND

[0002] In the traditional photovoltaic roof design, the photovoltaic roof is often installed in a flat or inclined manner, and a fixed-height ventilation cavity is arranged between the photovoltaic array and the roof, and the entire system relies only on natural convection to achieve heat dissipation, which is difficult to meet the heat dissipation demand under high load; in the existing photovoltaic curtain wall technology, the thickness of the cavity between the photovoltaic curtain wall assembly and the building outer wall is mostly fixed at 0.1-0.2m, and the size of the ventilation opening is mostly uniformly set without distinguishing the orientation of the curtain wall.

[0003] The traditional design has obvious defects: on the one hand, the thickness of the ventilation cavity is mostly determined depending on experience, when the thickness of the ventilation cavity is insufficient, the average wind speed in the ventilation cavity is small, and the heat on the surface of the photovoltaic assembly cannot be dissipated in time, resulting in excessively high temperature of the assembly, and thus reducing the photoelectric conversion efficiency of the photovoltaic assembly; when the thickness of the ventilation cavity is too large, the amount of bracket material is increased, and the cost is increased; on the other hand, the cavity design of the traditional photovoltaic curtain wall does not adjust the size of the ventilation opening according to the orientation difference (such as using a homogenization design scheme for the opening height of the ventilation opening of the north-south facade), resulting in significant increase of the building cooling energy consumption in summer and heating energy consumption in winter. SUMMARY

[0004] The present application overcomes the deficiencies of the prior art and provides an integrated ventilation and heat exchange system of a photovoltaic roof and a photovoltaic curtain wall and a design method, which realizes the goals of effectively reducing the working temperature of the photovoltaic assembly, significantly improving the photoelectric conversion efficiency thereof, and constructing a roof-curtain wall collaborative ventilation system, and thus solves the problem of insufficient energy efficiency caused by the independent operation of the existing photovoltaic roof and photovoltaic curtain wall.

[0005] To achieve the above-mentioned purposes, the technical solutions adopted by the present application are as follows: The present application provides, in a first aspect, an integrated ventilation and heat exchange system of a photovoltaic roof and a photovoltaic curtain wall.

[0006] characterized in that it comprises: a PLC controller, a heat dissipation fan, an adjustable steel bracket installed on the roof, a photovoltaic curtain wall assembly arranged on the wall, a photovoltaic roof assembly, and a temperature sensor; One end of the adjustable steel bracket is connected with the photovoltaic roof assembly, and a ventilation cavity is formed between the photovoltaic roof assembly and the roof through the support of the adjustable steel bracket; The temperature sensors are respectively installed on the back of the photovoltaic roof assembly, the back of the photovoltaic curtain wall assembly and indoors, and are used for collecting the back temperature of the photovoltaic roof assembly, the back temperature of the photovoltaic curtain wall assembly and the indoor temperature. When the difference between the back temperature of the photovoltaic roof assembly and the indoor temperature or the difference between the back temperature of the photovoltaic curtain wall assembly and the indoor temperature collected by the temperature sensor is greater than a preset threshold value, the PLC controller starts the heat dissipation fan.

[0007] Further, in the integrated ventilation and heat exchange system, the photovoltaic roof assembly is connected to the adjustable steel support through inclined beams and cross beams, so that the space between the photovoltaic roof assembly and the roof forms the ventilation cavity.

[0008] Further, in the integrated ventilation and heat exchange system, the space between the photovoltaic curtain wall assembly and the wall forms a curtain wall cavity, and adjustable air vents are respectively arranged above and below the photovoltaic curtain wall assembly, and the height of the adjustable air vent can be dynamically adjusted according to the orientation and height of the curtain wall.

[0009] Further, in the integrated ventilation and heat exchange system, the heat dissipation fan is arranged in a non-office area, and is wrapped with sound insulation cotton around, so as to reduce the noise generated when the fan operates.

[0010] The second aspect of the present application provides a design method of an integrated ventilation and heat exchange system of a photovoltaic roof and a photovoltaic curtain wall, which is applied to the integrated ventilation and heat exchange system of any one of the first aspect of the present application, and comprises the following steps: The length of the photovoltaic array and the inclination angle of the photovoltaic array are obtained, and the thickness of the roof ventilation cavity is quantified according to the length of the photovoltaic array and the inclination angle of the photovoltaic array. The equivalent heat transfer coefficient of the air layer is obtained, and the outdoor comprehensive temperature and the indoor temperature are obtained, and the convective heat transfer coefficient and the radiative heat transfer coefficient of the air layer in the cavity are calculated according to the outdoor comprehensive temperature and the indoor temperature. The total heat transfer coefficient of the air layer in the cavity is calculated according to the equivalent heat transfer coefficient of the air layer, the convective heat transfer coefficient and the radiative heat transfer coefficient of the air layer in the cavity, and the cavity channel width is determined according to the total heat transfer coefficient. The height of the adjustable air vent is determined according to the orientation and height of the curtain wall, the wind speed of the heat dissipation fan is calculated according to the temperature of the photovoltaic roof assembly, the temperature of the photovoltaic curtain wall assembly and the indoor temperature, and the integrated ventilation and heat exchange system is cooperatively controlled according to the cavity channel width and the wind speed of the heat dissipation fan.

[0011] Further, in the design method, the thickness of the roof ventilation cavity is determined according to the length of the photovoltaic array and the inclination angle of the photovoltaic array, and specifically: The photovoltaic array is connected to the horizontal beams via inclined beams and fixed to an adjustable steel bracket. This adjustable steel bracket is installed above the roof structure, creating a roof ventilation cavity of thickness H between the photovoltaic roof components and the roof. The thickness H of the roof ventilation cavity is quantified using the following formula: ; In the formula: L – Length of the photovoltaic array, in meters (m); — Array tilt angle, in degrees.

[0012] Furthermore, in the design method, the convective thermal conductivity and radiative thermal conductivity of the cavity air gap are calculated based on the outdoor combined temperature and the indoor temperature, specifically including: Convection thermal conductivity of the air space in the cavity It is calculated from the following relationship: ; In the formula: — Convection thermal conductivity of the air interlayer in the cavity, in W / (m·K); —Indoor-outdoor temperature difference, in K; —Cavity channel width, in meters; Summer outdoor average temperature, in Kelvin (K). Indoor temperature, in K; Radiative thermal conductivity of the air interlayer in the cavity It is calculated from the following relationship:

[0013] In the formula: —Radiative thermal conductivity of the air interlayer in the cavity, in W / (m·K); —Surface emissivity of photovoltaic modules, with a value of 0.84; —The emissivity of the wall surface, with a value of 0.54; —Stefant-Boltzmann constant, with a value of 5.67 × 10⁻⁶ -8 W / (m 2 ·K 4 ).

[0014] Furthermore, in the design method, the total heat transfer coefficient of the air space in the cavity is calculated based on the equivalent heat transfer coefficient of the air layer, the convective thermal conductivity of the air space in the cavity, and the radiative thermal conductivity of the air space in the cavity, specifically as follows: Under steady-state conditions, the overall heat transfer coefficient of the air interlayer in the cavity It is derived from the following calculation formula: ; In the formula: —The overall heat transfer coefficient of the air gap in the cavity, in W / (m²). 2 ·K); —Equivalent heat transfer coefficient of the air layer in the cavity, in W / (m·K); —The convective equivalent heat transfer coefficient of the air layer in the cavity, in W / (m·K); —Radiative equivalent heat transfer coefficient of the air interlayer in the cavity, expressed in W / (m·K).

[0015] The cavity channel width is determined based on the calculated total heat transfer coefficient of the air interlayer in the cavity.

[0016] Furthermore, in the design method, the height of the adjustable ventilation openings of the photovoltaic curtain wall is determined as follows: The height h of the ventilation opening is calculated using the following formula: ; In the formula: —Orientation correction factor for curtain wall: South facade =1.0, East / West facade =0.7, north elevation =0.5; —Curtain wall height, m; Furthermore, in the design method, the wind speed of the cooling fan is calculated based on the temperature of the photovoltaic roof module, the temperature of the photovoltaic curtain wall module, and the indoor temperature. It is calculated using the following formula: ; In the formula: Temperature of the photovoltaic rooftop module, in Kelvin (K). Temperature of the photovoltaic curtain wall components, in Kelvin (K). The indoor temperature is expressed in Kelvin (K).

[0017] This invention effectively solves the defects existing in the background technology. Compared with the prior art, it achieves technological breakthroughs in multiple dimensions such as heat dissipation efficiency, structural adaptability, and cost economy. The specific beneficial effects are as follows: This invention establishes an integrated "roof-curtain wall" ventilation system by installing adjustable steel supports on the photovoltaic roof (dynamically adjusting the thickness of the roof ventilation cavity based on parameters such as photovoltaic array length and tilt angle) and optimizing the height of adjustable vents to accommodate differences in curtain wall height and orientation. When a temperature sensor detects a temperature difference between the back of the photovoltaic roof components or the back of the photovoltaic curtain wall components and the indoor temperature exceeding a preset threshold, the coordinated ventilation control module drives the cooling fan and vents to actively ventilate, promptly expelling heat from the roof ventilation cavity and curtain wall cavity. This effectively solves the problem of insufficient heat dissipation efficiency in traditional independent ventilation systems for photovoltaic roofs and curtain walls, significantly reduces the operating temperature of photovoltaic components, and extends their lifespan. Compared to traditional photovoltaic roofs... The fixed design of the roof's "non-adjustable ventilation cavity thickness" allows for dynamic and precise matching of the roof ventilation cavity thickness with photovoltaic array parameters, reducing the amount of support materials used and directly lowering construction costs. It also shortens the project's investment payback period and improves the economic feasibility of the technology. Unlike the crude design of traditional photovoltaic curtain walls with "homogeneous ventilation opening heights," this invention uses a differentiated ventilation opening design to increase the flow velocity at the center of the curtain wall cavity, enhancing the convective heat transfer effect within the cavity. This fundamentally solves the problem of "insufficient heat dissipation leading to efficiency degradation of photovoltaic curtain wall components" in traditional designs, effectively improving the photoelectric conversion efficiency of photovoltaic modules. Furthermore, this design considers the energy consumption optimization needs of building cooling in summer and heating in winter, further reducing the overall energy consumption of the building. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings required in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained from these drawings without creative effort.

[0019] Figure 1 A schematic diagram of the integrated ventilation and heat exchange system of photovoltaic roof and photovoltaic curtain wall is shown; Figure 2 A cross-sectional view of a photovoltaic rooftop unit is shown; Figure 3 A cross-sectional view of a photovoltaic curtain wall unit is shown; Figure 4 A cross-sectional view of the collaborative ventilation control module is shown; Figure 5 A flowchart of the collaborative ventilation control module is shown.

[0020] The components corresponding to the markings in the attached diagram are as follows: 1-Adjustable steel bracket, 2-Photovoltaic roof module, 3-Ventilation cavity, 4-Cooling fan, 5-Ventilation opening, 6-Photovoltaic curtain wall module, 7-Cavity, 8-Slanted beam, 9-Horizontal beam, 10-Roof, 11-Wall, 12-Temperature sensor, 13-PLC controller. Detailed Implementation

[0021] To more clearly understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the accompanying drawings are simplified schematic diagrams, illustrating only the basic structure of the present invention, and therefore only show the components relevant to the present invention; without conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0022] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing this invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the scope of protection of this invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and do not have the meaning of indicating or implying relative importance, nor do they imply the number of indicated technical features; therefore, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0023] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly: for example, they can realize fixed connection, detachable connection, or integral connection; they can realize mechanical connection or electrical connection; they can be directly connected or indirectly connected through an intermediate medium; and they can also realize communication between the internal parts of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0024] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. The drawings illustrate preferred embodiments of the invention, but the invention is not limited to the embodiments described herein; rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of the present invention.

[0025] Combination Figures 1 to 5 The first aspect of the present invention provides an integrated ventilation and heat exchange system for a photovoltaic roof and a photovoltaic curtain wall, the system comprising: The system includes a PLC controller 13, a cooling fan 4, an adjustable steel bracket 1 installed on the roof 10, a photovoltaic curtain wall assembly 6 installed on the wall 11, a photovoltaic roof assembly 2, and a temperature sensor 12. One end of the adjustable steel bracket 1 is connected to the photovoltaic roof module 2, and the other end is fixed to the roof 10. The photovoltaic roof module 2 is fixed to the adjustable steel bracket 1 through the inclined beam 8 and the cross beam 9. The support height of the adjustable steel bracket 1 is adjusted so that the space between the photovoltaic roof module 2 and the roof 10 forms a roof ventilation cavity 3 with adjustable thickness. The space between the photovoltaic curtain wall module 6 and the wall 11 forms a curtain wall cavity 7. The photovoltaic curtain wall module 6 is provided with adjustable ventilation openings 5 ​​at the top and bottom (the ventilation openings are preferably made of aluminum alloy louvers, and the opening degree can be controlled by the PLC controller 13). The temperature sensors 12 are respectively installed on the back of the photovoltaic roof module 2, the back of the photovoltaic curtain wall module 6, and the indoor environment to collect the temperature of the back of the photovoltaic roof module 2, the back of the photovoltaic curtain wall module 6, and the indoor temperature. When the temperature sensor 12 detects that either the temperature difference between the back of the photovoltaic roof module 2 and the indoor environment or the temperature difference between the back of the photovoltaic curtain wall module 6 and the indoor environment is greater than a preset threshold, the PLC controller 13 starts the cooling fan 4 and adjusts the opening of the adjustable vent 5 to discharge the heat in the roof ventilation cavity 3 and the curtain wall cavity 7 in a timely manner, so as to achieve energy saving and cooling, ensure the stable operation of the photovoltaic roof module 2 and the photovoltaic curtain wall module 6, and improve the photoelectric conversion efficiency. In addition, the cooling fan 4 is located in a non-office area and is surrounded by sound insulation cotton to reduce the noise generated when the fan is running.

[0026] A second aspect of the present invention provides a design method for an integrated ventilation and heat exchange system of photovoltaic roof and photovoltaic curtain wall, wherein the design method is applied to the integrated ventilation and heat exchange system described in any one of the first aspects of the present invention, and includes the following steps: Obtain the length and tilt angle of the photovoltaic array, and quantify the thickness of the roof ventilation cavity based on the length and tilt angle of the photovoltaic array. The equivalent heat transfer coefficient of the air layer is obtained, and the outdoor comprehensive temperature and indoor temperature are obtained. The convective thermal conductivity and radiative thermal conductivity of the air gap in the cavity are calculated based on the outdoor comprehensive temperature and indoor temperature. The total heat transfer coefficient of the air interlayer in the cavity is calculated based on the equivalent heat transfer coefficient of the air layer, the convective heat transfer coefficient of the air interlayer in the cavity, and the radiative heat transfer coefficient of the air interlayer in the cavity, and the width of the cavity channel is determined based on the total heat transfer coefficient. The height of the adjustable ventilation opening is determined based on the orientation and height of the curtain wall, and the wind speed of the cooling fan is calculated based on the temperature of the photovoltaic roof module, the temperature of the photovoltaic curtain wall module, and the indoor temperature. The integrated ventilation and heat exchange system is then controlled in a coordinated manner according to the cavity channel width and the wind speed of the cooling fan.

[0027] Furthermore, in the design method, the total heat transfer coefficient of the air space in the cavity is calculated based on the equivalent heat transfer coefficient of the air layer, the convective thermal conductivity of the air space in the cavity, and the radiative thermal conductivity of the air space in the cavity, specifically as follows: Under steady-state conditions, the overall heat transfer coefficient of the air interlayer in the cavity It is derived from the following calculation formula: ; In the formula: —The overall heat transfer coefficient of the air gap in the cavity, in W / (m²). 2 ·K); —Equivalent heat transfer coefficient of the air layer in the cavity, in W / (m·K); —The convective equivalent heat transfer coefficient of the air layer in the cavity, in W / (m·K); —Radiative equivalent heat transfer coefficient of the air interlayer in the cavity, expressed in W / (m·K).

[0028] The cavity channel width is determined based on the calculated total heat transfer coefficient of the air layer within the cavity. Further, in the design method, the ventilation cavity thickness is calculated and determined based on the photovoltaic array length and the photovoltaic array tilt angle, specifically as follows: The photovoltaic array is connected to the horizontal beams via inclined beams and fixed to an adjustable steel bracket. This adjustable steel bracket is installed above the roof structure, creating a roof ventilation cavity of thickness H between the photovoltaic roof components and the roof. The thickness H of the roof ventilation cavity is quantified using the following formula: ; In the formula: L – Length of the photovoltaic array, in meters (m); — Array tilt angle, in degrees.

[0029] According to relevant materials in "Heat Transfer", the mean temperature of the air layer is... The equivalent heat transfer coefficient of the air layer at 20℃ It is 0.0259 W / (m·K); in At 30℃, It is 0.0267 W / (m·K); in At 40℃, It is 0.0276 W / (m·K).

[0030] In this embodiment, summer operating conditions are taken as an example: outdoor comprehensive temperature The indoor temperature was 37.2℃. The temperature is 26℃, and the arithmetic mean of the two is... The value is 31.6℃. Since 31.6℃ is close to 30℃, the equivalent heat transfer coefficient of the air layer is used as an approximation. It is 0.0267 W / (m·K).

[0031] Furthermore, in the design method, the convective thermal conductivity and radiative thermal conductivity of the cavity air gap are calculated based on the outdoor combined temperature and the indoor temperature, specifically including: Convection thermal conductivity of the air space in the cavity It is calculated from the following relationship: ; In the formula: — Convection thermal conductivity of the air interlayer in the cavity, in W / (m·K); —Indoor-outdoor temperature difference, in K; —Cavity channel width, in meters; Summer outdoor average temperature, in Kelvin (K). Indoor temperature, in K; Radiative thermal conductivity of the air interlayer in the cavity It is calculated from the following relationship: ; In the formula: —Radiative thermal conductivity of the air interlayer in the cavity, in W / (m·K); —Surface emissivity of photovoltaic modules, with a value of 0.84; —The emissivity of the wall surface, with a value of 0.54; —Stefant-Boltzmann constant, with a value of 5.67 × 10⁻⁶ -8 W / (m 2 ·K 4 ).

[0032] The above regarding , , Substituting the formula into the overall heat transfer coefficient calculation formula, we can obtain the following: ; When the thickness of the curtain wall cavity is 0.066m, the total heat transfer coefficient of the air layer in the cavity is the lowest, corresponding to the optimal thermal insulation performance of the building.

[0033] Therefore, for office buildings in Hefei, the photovoltaic curtain wall components in this system are set parallel to the building's exterior wall to form a 0.066m thick curtain wall cavity, with adjustable ventilation openings located at the top and bottom of the curtain wall.

[0034] Furthermore, in the design method, the height of the adjustable ventilation openings of the photovoltaic curtain wall is determined as follows: The height h of the ventilation opening is calculated using the following formula: ; In the formula: —Orientation correction factor for curtain wall: South facade =1.0, East / West facade =0.7, north elevation =0.5; —Curtain wall height, m; Furthermore, in the design method, the wind speed of the cooling fan is calculated based on the temperature of the photovoltaic roof module, the temperature of the photovoltaic curtain wall module, and the indoor temperature. It is calculated using the following formula: ; In the formula: Temperature of the photovoltaic rooftop module, in Kelvin (K). Temperature of the photovoltaic curtain wall components, in Kelvin (K). The indoor temperature is expressed in Kelvin (K).

[0035] For example, when the temperature of photovoltaic rooftop modules =320K, temperature of photovoltaic curtain wall components At 315K, the indoor temperature =299K, substituting into the fan speed calculation formula, we get: v=1.5+0.2×(320-299)=5.7m / s. At this time, start the cooling fan and adjust the operating parameters according to the calculated fan speed (5.7m / s).

[0036] It should be noted that the temperature sensor is used to monitor the temperature of the photovoltaic module. Photovoltaic curtain wall temperature With indoor temperature And transmit the data to the PLC controller in real time, when ≥5K or At ≥5K, the system starts the cooling fan and simultaneously achieves active ventilation of the roof ventilation cavity and curtain wall cavity through the collaborative ventilation control module. The height of the adjustable ventilation opening is optimized according to the height and orientation of the curtain wall to expel heat from the cavity in a timely manner. This not only reduces the temperature in the roof ventilation cavity and curtain wall cavity, but also improves the photoelectric conversion efficiency of the photovoltaic modules and extends their service life.

[0037] Furthermore, a correlation model is established between the photovoltaic module's photoelectric conversion efficiency η and ventilation parameters, which is expressed by the following relationship: ; In the formula: —Solar cell module efficiency at AM1.5 (the actual distance of light passing through the atmosphere is 1.5 times the vertical thickness of the atmosphere), solar irradiance of 1000W / ㎡, and ambient temperature of 25℃ (typical efficiency is 20%). — Photovoltaic module temperature, K.

[0038] For example, the temperature of the photovoltaic rooftop module of the system of this invention was measured at noon in summer. =315K (Temperature of conventionally designed photovoltaic rooftop modules) =322K), compared to the traditional design, the photovoltaic rooftop module temperature of the present invention is reduced by 7K, and the photoelectric conversion efficiency is correspondingly increased by 0.63%; substituting into the aforementioned photovoltaic module efficiency calculation formula, the photoelectric conversion efficiency of the photovoltaic module at this time can be obtained. =18.48%.

[0039] The formulas for calculating the building's energy efficiency rate and overall energy efficiency rate are as follows: ;

[0040] ;

[0041] ;

[0042] ;

[0043] In the formula: —Comprehensive building energy consumption excluding renewable energy generation, kWh / (㎡·a); —Comprehensive building energy consumption including renewable energy generation, kWh / (㎡·a); —Baseline building energy consumption (kWh / (㎡·a)); —These are the annual equipment energy consumption, lighting energy consumption, heating energy consumption, and cooling energy consumption of the designed building, in kWh; —Annual electricity generation for Class i energy source, in kWh; —The energy conversion coefficient for type i is 2.6 for electrical energy; —Building area, square meters; —These refer to the building's energy efficiency rate and the building's overall energy efficiency rate, respectively.

[0044] Calculations based on the above relationships show that the temperature fluctuations of both photovoltaic rooftop modules and photovoltaic curtain wall modules are controlled within ±5K, which is 50% lower than existing technologies. The overall energy saving rate of this system is ≥60%, which is 33.3%-41.4% higher than traditional independent ventilation designs for photovoltaic rooftops and curtain walls. Compared to traditional ventilation systems, the ventilation system cost of this system is reduced by 10%-15%.

[0045] In summary, compared with the traditional photovoltaic roof design with non-adjustable ventilation cavity thickness, this invention can effectively reduce the amount of support material used, lower system construction costs, and shorten the project investment payback period by dynamically matching the ventilation cavity thickness with photovoltaic array parameters. Compared with the traditional photovoltaic curtain wall design with homogeneous ventilation opening height, this invention can significantly increase the flow velocity at the center of the curtain wall cavity through the design of ventilation openings with differentiated orientations, enhance the heat dissipation effect inside the curtain wall cavity, and ultimately improve the photoelectric conversion efficiency of the photovoltaic curtain wall components.

[0046] In addition, this method also includes an intelligent control module based on deep reinforcement learning (DRL), the specific steps of which are as follows: Sensors are deployed in this integrated ventilation and heat exchange system, and an environmental parameter control model is constructed based on the deep reinforcement learning (DRL) algorithm. This model uses a sensor data matrix consisting of temperature, light intensity, and building energy consumption data as the state space, shading coefficient and vent opening parameters as the action space, and energy savings, indoor air quality compliance rate, and photovoltaic module power generation efficiency as quantifiable reward functions. The environmental parameter control model collects real-time sensor data, inputs it into the model for analysis, learns online, and continuously updates parameters to obtain control parameters for shading coefficient and vent opening. At the same time, the model automatically identifies the impact of building orientation and floor height on ventilation demand and dynamically adjusts the above control parameters.

[0047] Furthermore, by applying deep reinforcement learning (DRL) algorithms to construct a multi-objective intelligent ventilation control strategy aimed at energy saving, indoor air quality optimization, and improved photovoltaic module power generation efficiency, the shading coefficient and ventilation opening parameters can be further optimized. For example, this method can achieve refined control to address the differentiated needs of prioritizing heat dissipation for south-facing curtain walls and focusing on insulation for north-facing curtain walls.

[0048] In addition, this method also includes a predictive control step based on digital twins and LSTM neural networks: Real-time data on the temperature of photovoltaic rooftop modules, photovoltaic curtain wall modules, indoor and outdoor temperature and humidity, and light intensity are collected. Based on virtual simulation technology, a 1:1 mapping of the physical entity of this integrated ventilation and heat exchange system to a three-dimensional digital twin model is constructed in virtual space. Data on the power generation efficiency change of this model under the current operating conditions is collected and used as training samples to train an LSTM neural network. The trained LSTM neural network predicts the power generation efficiency change trend under the current photovoltaic module operating temperature. When the amplitude of this trend exceeds a preset threshold, initial control parameters for the vent opening and fan speed are initialized and output. Based on the above initial control parameters, heat dissipation simulation is performed on the operating temperature of the photovoltaic rooftop modules and photovoltaic curtain wall modules to obtain temperature characteristics within a preset time period. If at least one temperature data point in the temperature characteristics within the preset time period is lower than the warning threshold and the system meets the requirements for stable operation, the current vent opening and fan speed parameters will be output, and the ventilation system will be optimized according to these parameters. If no temperature data is below the warning threshold within the preset time period, the ventilation opening and fan speed parameters will be re-optimized based on the temperature deviation value.

[0049] It should be noted that temperature affects the power generation efficiency and lifespan of photovoltaic modules. By constructing a digital twin model of the photovoltaic ventilation system and combining real-time data mapping and virtual simulation, the opening degree of the ventilation opening and the fan speed parameters can be further optimized to maintain the high-efficiency power generation performance of the photovoltaic modules.

[0050] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity, and those skilled in the art should consider the specification as a whole. The technical solutions in the various embodiments can be appropriately combined without conflict, and, after being understood by those skilled in the art, can form other implementable methods.

[0051] The above embodiments are merely specific implementations of the present invention, used to illustrate the technical solutions of the present invention, and not to limit it. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that within the technical scope disclosed in the present invention, those skilled in the art can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features; such modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An integrated ventilation and heat exchange system for photovoltaic rooftops and photovoltaic curtain walls, characterized in that, include: PLC controller, cooling fan, adjustable steel bracket installed on the roof, photovoltaic curtain wall module installed on the wall, photovoltaic roof module, and temperature sensor; One end of the adjustable steel bracket is connected to the photovoltaic roof module, and the adjustable steel bracket supports the formation of a ventilation cavity between the photovoltaic roof module and the roof. The temperature sensors are respectively installed on the back of the photovoltaic roof module, the back of the photovoltaic curtain wall module, and the indoor environment, and are used to collect the temperature of the back of the photovoltaic roof module, the temperature of the back of the photovoltaic curtain wall module, and the indoor temperature; When the temperature difference between the back of the photovoltaic roof module and the indoor temperature, or the temperature difference between the back of the photovoltaic curtain wall module and the indoor temperature, is greater than a preset threshold, the PLC controller starts the cooling fan.

2. The integrated ventilation and heat exchange system for photovoltaic roofs and photovoltaic curtain walls according to claim 1, characterized in that, The photovoltaic roof module is connected to the adjustable steel bracket by inclined beams and crossbeams, so that the space between the photovoltaic roof module and the roof forms the ventilation cavity.

3. The integrated ventilation and heat exchange system for photovoltaic roofs and photovoltaic curtain walls according to claim 1, characterized in that, The space between the photovoltaic curtain wall component and the wall forms a curtain wall cavity, and adjustable ventilation openings are provided above and below the photovoltaic curtain wall component. The height of the adjustable ventilation openings can be dynamically adjusted according to the orientation and height of the curtain wall.

4. The integrated ventilation and heat exchange system for photovoltaic roofs and photovoltaic curtain walls according to claim 1, characterized in that, The cooling fan is located in a non-office area and is surrounded by sound-absorbing cotton to reduce the noise generated when the fan is running.

5. A design method for an integrated ventilation and heat exchange system of photovoltaic roof and photovoltaic curtain wall, characterized in that, An integrated ventilation and heat exchange system for photovoltaic roofs and photovoltaic curtain walls as described in any one of claims 1-4, comprising the following steps: Obtain the length and tilt angle of the photovoltaic array, and quantify the thickness of the roof ventilation cavity based on the length and tilt angle of the photovoltaic array. The equivalent heat transfer coefficient of the air layer is obtained, and the outdoor comprehensive temperature and indoor temperature are obtained. The convective thermal conductivity and radiative thermal conductivity of the air gap in the cavity are calculated based on the outdoor comprehensive temperature and indoor temperature. The total heat transfer coefficient of the air interlayer in the cavity is calculated based on the equivalent heat transfer coefficient of the air layer, the convective heat transfer coefficient of the air interlayer in the cavity, and the radiative heat transfer coefficient of the air interlayer in the cavity, and the width of the cavity channel is determined based on the total heat transfer coefficient. The height of the adjustable ventilation opening is determined based on the orientation and height of the curtain wall, and the wind speed of the cooling fan is calculated based on the temperature of the photovoltaic roof module, the temperature of the photovoltaic curtain wall module, and the indoor temperature. The integrated ventilation and heat exchange system is then controlled in a coordinated manner according to the cavity channel width and the wind speed of the cooling fan.

6. The design method of an integrated ventilation and heat exchange system for a photovoltaic roof and a photovoltaic curtain wall according to claim 5, characterized in that, The thickness of the roof ventilation cavity is calculated based on the length and tilt angle of the photovoltaic array, specifically as follows: The photovoltaic array is connected to the horizontal beams via inclined beams and fixed to an adjustable steel bracket. This adjustable steel bracket is installed above the roof structure, creating a roof ventilation cavity of thickness H between the photovoltaic roof components and the roof. The thickness H of the roof ventilation cavity is quantified using the following formula: ； In the formula: L – Length of the photovoltaic array, in meters (m); —Array tilt angle, in degrees.

7. The design method of an integrated ventilation and heat exchange system for a photovoltaic roof and a photovoltaic curtain wall according to claim 5, characterized in that, The convective thermal conductivity and radiative thermal conductivity of the air gap in the cavity are calculated based on the outdoor combined temperature and the indoor temperature, specifically including: Convection thermal conductivity of the air space in the cavity It is calculated from the following relationship: ； In the formula: — Convection thermal conductivity of the air interlayer in the cavity, in W / (m·K); —Indoor-outdoor temperature difference, in K; —Cavity channel width, in meters; Summer outdoor average temperature, in Kelvin (K). Indoor temperature, in Kelvin (K). Radiative thermal conductivity of the air interlayer in the cavity It is calculated from the following relationship: ； In the formula: —Radiative thermal conductivity of the air interlayer in the cavity, in W / (m·K); —Surface emissivity of photovoltaic modules, with a value of 0.84; —The emissivity of the wall surface, with a value of 0.54; The Stefan-Boltzmann constant has a value of 5.67 × 10⁻⁶. -8 W / (m 2 ·K 4 ).

8. The design method of an integrated ventilation and heat exchange system for a photovoltaic roof and a photovoltaic curtain wall according to claim 5, characterized in that, The overall heat transfer coefficient of the air space in the cavity is calculated based on the equivalent heat transfer coefficient of the air layer, the convective thermal conductivity of the air space in the cavity, and the radiative thermal conductivity of the air space in the cavity. Specifically: Under steady-state conditions, the overall heat transfer coefficient of the air interlayer in the cavity It is derived from the following calculation formula: ； In the formula: —The overall heat transfer coefficient of the air gap in the cavity, in W / (m²). 2 ·K); —Equivalent heat transfer coefficient of the air layer in the cavity, in W / (m·K); —The convective equivalent heat transfer coefficient of the air layer in the cavity, in W / (m·K); —Radiative equivalent heat transfer coefficient of the air interlayer in the cavity, in units of W / (m·K); The cavity channel width is determined based on the calculated total heat transfer coefficient of the air interlayer in the cavity.

9. The design method of an integrated ventilation and heat exchange system for a photovoltaic roof and a photovoltaic curtain wall according to claim 5, characterized in that, The height of the adjustable ventilation openings on the photovoltaic curtain wall is determined as follows: The height h of the ventilation opening is obtained by the following formula: ； In the formula: —Orientation correction factor for curtain wall: South facade =1.0, East / West facade =0.7, north elevation =0.5; — Curtain wall height, m.

10. The design method of an integrated ventilation and heat exchange system for a photovoltaic roof and a photovoltaic curtain wall according to claim 5, characterized in that, The airflow speed of the cooling fan is calculated based on the temperatures of the photovoltaic rooftop modules, photovoltaic curtain wall modules, and the indoor temperature. It is calculated using the following formula: ； In the formula: Temperature of the photovoltaic rooftop module, in Kelvin (K). Temperature of the photovoltaic curtain wall components, in Kelvin (K). The indoor temperature is expressed in Kelvin (K).

Images