A metal roof health monitoring method and early warning system for BIPV photovoltaic power stations

Abstract

The present invention discloses a metal roof health monitoring method and early warning system for BIPV photovoltaic power station, which collects deformation data, temperature data, wind data, rainfall data and drainage gutter data of metal roof panels in real time when the metal roof is in operation; calculates the thermal expansion and contraction temperature safety threshold, lateral deformation theoretical value and gutter drainage capacity theoretical value of the metal roof panels according to the measured data; sets the lateral deformation safety threshold and gutter drainage capacity safety threshold of the metal roof; compares at least one parameter value of the measured current temperature data, lateral deformation theoretical value and gutter drainage capacity theoretical value of the metal roof with the corresponding thermal expansion and contraction temperature safety threshold, lateral deformation safety threshold and gutter drainage capacity safety threshold, and determines whether to give an early warning for the health of the metal roof. The present invention can timely judge safety hazards, remind operation and maintenance personnel to take precautions in advance, and ensure the safe operation of the BIPV photovoltaic power station in extreme weather.

Description

Technical Field

[0001] The present invention relates to the field of safety monitoring of metal enclosure structures, and in particular to a metal roof health monitoring method and early warning system for a BIPV photovoltaic power station. Background Art

[0002] BIPV (Building Integrated Photovoltaic) has both power generation and building properties, and its health assessment also needs to take into account both power generation equipment and building structures. Nowadays, some extreme weather, such as high temperatures, typhoons, and heavy rains, often occur in certain seasons, which affects the safe operation of BIPV and, in severe cases, causes significant asset losses. In view of the impact that these extreme weather conditions may have on building structures, an early warning mechanism is needed to alert operation and maintenance personnel. The alarm and warning module functions in the BIPV monitoring system currently on the market are basically aimed at power generation equipment. Therefore, it is necessary to design an early warning system for the building structure part of BIPV to make up for the shortcomings of this type of monitoring system. Summary of the invention

[0003] In order to solve the current technical problems, the present invention provides a metal roof health monitoring method and early warning system for a BIPV photovoltaic power station. Based on real-time monitored building structure-related data and combined with weather forecasts, an algorithm is used to warn in advance of possible safety hazards in the BIPV building structure to avoid major losses.

[0004] The present invention adopts the following technical solution:

[0005] On the one hand, the present invention provides a method for monitoring the health of a metal roof for a BIPV photovoltaic power station, the specific method comprising: real-time collection of deformation data, temperature data, wind data, rainfall data, and drainage gutter data of a metal roof panel during operation of the metal roof;

[0006] According to the measured temperature data, deformation of the metal roof panel, wind data, precipitation data and drainage gutter data, the thermal expansion and contraction temperature safety threshold, the theoretical value of lateral deformation and the theoretical value of gutter drainage capacity of the metal roof panel are calculated;

[0007] Set the safety threshold of the lateral deformation of the metal roof and the safety threshold of the drainage capacity of the gutter;

[0008] The current temperature data, theoretical value of lateral deformation and theoretical value of gutter drainage capacity of the measured metal roof are compared with the corresponding thermal expansion and contraction temperature safety threshold, lateral deformation safety threshold and gutter drainage capacity safety threshold to determine whether to issue an early warning for the health of the metal roof.

[0009] Preferably, the specific method of giving early warning of the lateral deformation of the metal roof panel is:

[0010] The corresponding wind speed is obtained by collecting the wind force level from the weather forecast; the wind pressure is calculated using the Bernoulli equation; the theoretical lateral deformation of the metal roof panel is obtained by using the wind pressure and the constructed theoretical calculation model of the lateral deformation of the metal roof panel; the theoretical lateral deformation is compared with the set lateral deformation safety threshold to determine whether the future wind force will cause safety hazards to the metal roof panel.

[0011] Preferably, the specific method for early warning of the thermal expansion and contraction of the metal roof panel is:

[0012] Obtain the initial parameters of temperature and board length when installing the metal roof panel;

[0013] Collect the actual measured temperature and deformation of the current metal roof panel;

[0014] Set the safety threshold range for thermal expansion and contraction of metal roof panels;

[0015] A calculation model for the temperature deformation of metal roof panels is constructed, and the maximum temperature threshold range that the metal roof panels can withstand is obtained using the initial parameters and the safety threshold range.

[0016] The measured temperature is compared with the obtained temperature threshold range to determine whether to issue a warning message on the health of the metal roof.

[0017] Preferably, the constructed calculation model for the temperature deformation of the metal roof panel is as follows:

[0018] [S min ,S max ]=α×([t min , t max ]- t0)×k×L+S c ;

[0019] Among them: [S min ,S max ] is the set safety threshold range of thermal expansion and contraction of metal roof panels;

[0020] S c is the deformation amount of the current metal roof panel;

[0021] α is the linear expansion coefficient, a constant;

[0022] k is the adjustment coefficient, a constant;

[0023] t0 and L are the initial temperature and length of the panel when it is installed;

[0024] [t min , t max ] is the temperature threshold range to be obtained.

[0025] Preferably, the specific method of early warning the drainage capacity of the gutter of the metal roof is:

[0026] Based on the measured cross-sectional height and width of the drainage ditch, the actual water level of the drainage ditch is collected in real time;

[0027] Combined with the unit rainfall intensity in the weather forecast, calculate the rainfall received by the drainage ditch;

[0028] Based on the relevant theories of hydraulics, the drainage volume can be calculated through the height of the drainage ditch;

[0029] According to the safe operation condition that the drainage volume of the metal roof is greater than or equal to the rainfall, the minimum height of the drainage gutter is calculated to obtain the safety threshold of the drainage capacity of the gutter;

[0030] Calculate the difference between the drainage gutter height and the actual water level currently measured;

[0031] The difference height is compared with the safety threshold to determine whether to issue a warning message on the health of the metal roof.

[0032] On the other hand, the present invention also provides a metal roof health warning system for a BIPV photovoltaic power station, the system comprising:

[0033] Data acquisition module, which collects metal roof panel deformation data, temperature data, wind data, rainfall data and drainage gutter data in real time when the metal roof is in operation;

[0034] The data processing module calculates the thermal expansion and contraction temperature safety threshold of the metal roof panel, the theoretical value of the lateral deformation, and the theoretical value of the drainage capacity of the gutter according to the measured temperature data, the deformation of the metal roof panel, the wind data, the precipitation data, and the drainage gutter data;

[0035] The safety threshold module has thermal expansion and contraction temperature safety thresholds, lateral deformation safety thresholds, and gutter drainage capacity safety thresholds;

[0036] The early warning information release module compares the current temperature data, theoretical value of lateral deformation and theoretical value of gutter drainage capacity of the measured metal roof with the thermal expansion and contraction temperature safety threshold, lateral deformation safety threshold and gutter drainage capacity safety threshold in the safety threshold module. If at least one parameter in the measured data exceeds the corresponding set safety threshold, the metal roof health early warning information is released to the outside.

[0037] Preferably, the data acquisition module includes a water level sensor, a temperature sensor, a ranging sensor and a data collector; the water level sensor is installed in the gutter on the roof of the BIPV photovoltaic power station to measure the water level, the temperature sensor is installed on the metal roof panel to measure the temperature of the roof panel, and the ranging sensor is installed in the wind load area on the metal roof to measure the deformation of the roof panel; the data collector communicates with the water level sensor, temperature sensor and ranging sensor through an RS485 bus to obtain the measured data; the data collector is connected to the data processing module through a wireless transmission module.

[0038] The technical solution of the present invention has the following advantages:

[0039] A. The monitoring method and early warning system provided by the present invention can timely identify possible safety hazards based on the weather conditions at the location of the BIPV photovoltaic power station and the status data of building components, and remind operation and maintenance personnel to take preventive measures in advance, so as to ensure the safe operation of the BIPV photovoltaic power station in extreme weather or avoid major losses as much as possible.

[0040] B. The metal roof health warning system provided by the present invention uses the Internet of Things and sensor technology to obtain real-time data on the metal roof of the BIPV photovoltaic power station, combines it with weather forecasts, and then uses some theoretical formulas in architecture and fluid mechanics to analyze the safety problems that may arise in the BIPV photovoltaic power station under certain weather or environmental conditions, and sends warning information to operation and maintenance personnel.

[0041] C. The present invention combines the maximum and minimum thermal expansion and contraction of the metal roof panel with the temperature of the metal roof panel during initial installation to calculate the temperature threshold range that produces a safe value for thermal expansion and contraction, compares the measured temperature with the obtained temperature threshold range, and makes a judgment on the health of the metal roof, thereby realizing the judgment of the health of roof panels of different materials or thicknesses with high efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the specific embodiments of the present invention, the drawings required for use in the specific embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0043] Figure 1 It is a block diagram of the method for monitoring the health of a metal roof of a BIPV photovoltaic power station provided by the present invention;

[0044] Figure 2 This is a composition diagram of the metal roof health warning system of the BIPV photovoltaic power station provided by the present invention;

[0045] Figure 3 It is a flowchart of a specific method for early warning of the lateral deformation of the metal roof panel;

[0046] Figure 4 It is a flowchart of a specific method for early warning of thermal expansion and contraction of metal roof panels;

[0047] Figure 5 It is a flow chart of a specific method for early warning of the drainage capacity of the gutter of a metal roof. DETAILED DESCRIPTION

[0048] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0049] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0050] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0051] like Figure 1 As shown, the present invention provides a method for monitoring the health of a metal roof for a BIPV photovoltaic power station, which is as follows:

[0052]

S01

[0053]

S02

[0054]

S03

[0055] [S04] Compare the current temperature data, theoretical value of lateral deformation and theoretical value of gutter drainage capacity of the measured metal roof with at least one parameter value of the corresponding thermal expansion and contraction temperature safety threshold, lateral deformation safety threshold and gutter drainage capacity safety threshold to determine whether to issue an early warning for the health of the metal roof.

[0056] The specific method of early warning of the lateral deformation of the metal roof panel is:

[0057] The corresponding wind speed is obtained by collecting the wind force level from the weather forecast; the wind pressure is calculated using the Bernoulli equation; the theoretical lateral deformation of the metal roof panel is obtained by using the wind pressure and the constructed theoretical calculation model of the lateral deformation of the metal roof panel; the theoretical lateral deformation is compared with the set lateral deformation safety threshold to determine whether the future wind force will cause safety hazards to the metal roof panel.

[0058] like Figure 3 The detailed calculation process is as follows:

[0059] [S11] Set the safety value S of the lateral deformation of the metal roof panel: when the deformation is greater than or equal to S, the BIPV is in a dangerous operating state; when the deformation is less than S, the BIPV is in a safe operating state.

[0060] [S12] Obtain the weather forecast, obtain the future wind force level L, and obtain the wind speed v based on the wind force level.

[0061]

S13

[0062]

S14

[0063] d=k×ωo+b, where k and b are constants. According to the experimental values, they are taken as 9.8×10 -3 and -3.32, substituting into the wind pressure ωo, we can obtain the lateral deformation d of the roof panel.

[0064]

S14

[0065] like Figure 4 As shown in the figure, the specific method of early warning of the thermal expansion and contraction of metal roof panels is:

[0066]

S21

[0067]

S22

[0068]

S23

[0069] When the thermal expansion and contraction amount is within this range, the BIPV is in a safe operating state; when the thermal expansion and contraction amount exceeds this range, the BIPV is in a dangerous operating state.

[0070]

S24

[0071] The constructed calculation model of temperature deformation of metal roof panels is as follows:

[0072] [S min ,S max ]=α×([t min , t max ]- t0)×k×L+S c ①

[0073] Where: S c is the deformation amount of the current metal roof panel;

[0074] α is the linear expansion coefficient, a constant;

[0075] k is the adjustment coefficient, a constant;

[0076] t0 and L are the initial temperature and length of the panel when it is installed;

[0077] [t min , t max ] are the upper and lower limits of the obtained temperature threshold range.

[0078] The linear expansion coefficient α is 12x10 -6 / ℃ (according to Table 9.1.2 of the Code for Loads of Building Structures (GB-50009-2012), 730D corrugated steel roofing sheet), substitute the initial temperature t0, panel length L, and adjustment coefficient k when the panel is installed into the right side of the equal sign, and calculate the safety value range of thermal expansion and contraction of the panel S min , S max Substituting into the left side of the equal sign, we can calculate the upper and lower limits of the temperature threshold range of the object panel t min , t max .

[0079]

S25

[0080] like Figure 5 As shown, the specific method of early warning of the drainage capacity of the metal roof gutter is:

[0081]

S31

[0082]

S32

[0083]

S33

[0084] Assuming h is the height of the gutter water level, the effective water flow area is: A=W×h. According to the provisions of hydraulics, the hydraulic radius is the ratio of the water-passing cross-sectional area to the wetted perimeter, and the expression is: R=A / X, that is, R=A / (2×h+W).

[0085] According to the national standard "Outdoor Drainage Design Code" GB 50014-2021, the flow velocity of the drainage pipe under constant flow conditions should be calculated as follows:

[0086] ②

[0087] Where R is hydraulic radius (m); I is hydraulic gradient, which is 0.001; n is roughness coefficient, which is 0.012. Then the flow velocity can be calculated. .

[0088] The calculation formula for gutter drainage is: .

[0089]

S34

[0090] For BIPV to operate safely, the drainage volume must be greater than or equal to the rainfall volume, that is, Q ≥ P. Substituting the above parameters and calculation formula ②, it is: .

[0091] Through this formula, the minimum value of h can be finally obtained, which means that under certain rainfall conditions, the gutter must leave at least a height of h to drain water in time, that is, h is the safety threshold.

[0092] [S35] Calculate the height difference between the drainage gutter height and the actual water level currently measured.

[0093] Get the current drainage gutter water level h0, and calculate the difference between the drainage gutter height H and the current water level h0.

[0094] [S36] Compare the height difference with the safety threshold to determine whether to issue a warning message on the health of the metal roof.

[0095] If the obtained difference height is less than or equal to h, it is judged that the BIPV drainage capacity is insufficient and is in a dangerous operating state, and it is displayed on a web page or a text message is pushed to the BIPV photovoltaic power station operation and maintenance personnel; otherwise, the BIPV is in a safe operating state.

[0096] In addition, if Figure 2As shown, the present invention also provides a metal roof health warning system for BIPV photovoltaic power stations, including: a data acquisition module, a data processing module, a safety threshold module and a warning information release module. The data acquisition module collects the deformation data, temperature data, wind data, rainfall data and drainage gutter data of the metal roof in real time when the metal roof is in operation, and includes a water level sensor, a temperature sensor, a distance sensor and a data collector; the water level sensor is installed in the gutter on the roof of the BIPV photovoltaic power station to measure the water level, the temperature sensor is installed on the metal roof panel to measure the temperature of the roof panel, and the distance sensor is installed in the wind load area on the metal roof to measure the deformation of the roof panel. The data collector communicates with the water level sensor, temperature sensor and distance sensor through the RS485 bus to obtain the measured data; the data collector is connected to the data processing module through a wireless transmission module. The data processing module calculates the thermal expansion and contraction temperature safety threshold, lateral deformation theoretical value and gutter drainage capacity theoretical value of the metal roof panel according to the measured temperature data, deformation of the metal roof panel, wind data, precipitation data and drainage gutter data; the safety threshold module is provided with thermal expansion and contraction temperature safety threshold, lateral deformation safety threshold and gutter drainage capacity safety threshold; the early warning information release module compares the current temperature data, lateral deformation theoretical value and gutter drainage capacity theoretical value of the measured metal roof with the thermal expansion and contraction temperature safety threshold, lateral deformation safety threshold and gutter drainage capacity safety threshold in the safety threshold module; if at least one parameter in the measured data exceeds the corresponding set safety threshold, the metal roof health early warning information is released to the outside.

[0097] The above system uses the Internet of Things and sensor technology to obtain real-time data on the metal roof of the BIPV photovoltaic power station, combines it with weather forecasts, and then uses some theoretical formulas in architecture and fluid mechanics to analyze the safety problems that may arise in the BIPV photovoltaic power station under certain weather or environmental conditions, and sends early warning information to operation and maintenance personnel.

[0098] Anything not described in the present invention is applicable to the prior art.

[0099] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. However, the obvious changes or modifications derived therefrom are still within the scope of protection of the present invention.

Claims

1. A method for monitoring the health of a metal roof in a BIPV photovoltaic power station, characterized in that: Real-time collection of metal roof panel deformation data, temperature data, wind data, rainfall data and drainage gutter data during metal roof operation; According to the measured temperature data, deformation of the metal roof panel, wind data, precipitation data and drainage gutter data, the thermal expansion and contraction temperature safety threshold, the theoretical value of lateral deformation and the theoretical value of gutter drainage capacity of the metal roof panel are calculated; Set the safety threshold of the lateral deformation of the metal roof and the safety threshold of the drainage capacity of the gutter; Compare the current temperature data, the theoretical value of the lateral deformation and the theoretical value of the gutter drainage capacity of the measured metal roof with the corresponding thermal expansion and contraction temperature safety threshold, the lateral deformation safety threshold and the gutter drainage capacity safety threshold to determine whether to issue an early warning for the health of the metal roof; The specific method of early warning of the thermal expansion and contraction of metal roof panels is: Obtain the initial parameters of temperature and board length when installing the metal roof panel; Collect the actual measured temperature and deformation of the current metal roof panel; Set the safety threshold range for thermal expansion and contraction of metal roof panels; A calculation model for the temperature deformation of metal roof panels is constructed, and the maximum temperature threshold range that the metal roof panels can withstand is obtained using the initial parameters and the safety threshold range. The measured temperature is compared with the obtained temperature threshold range to determine whether to issue a warning message on the health of the metal roof.

2. The method for monitoring the health of a metal roof in a BIPV photovoltaic power station according to claim 1, characterized in that: The specific method of early warning of the lateral deformation of the metal roof panel is: The corresponding wind speed is obtained by collecting the wind force level from the weather forecast; the wind pressure is calculated using the Bernoulli equation; the theoretical lateral deformation of the metal roof panel is obtained by using the wind pressure and the constructed theoretical calculation model of the lateral deformation of the metal roof panel; the theoretical lateral deformation is compared with the set lateral deformation safety threshold to determine whether the future wind force will cause safety hazards to the metal roof panel.

3. The method for monitoring the health of a metal roof for a BIPV photovoltaic power station according to claim 2, characterized in that: The constructed calculation model of temperature deformation of metal roof panels is as follows: [S min ,S max ]=α×([t min , t max ]- t0)×k×L+S c ; Among them: [S min ,S max ] is the set safety threshold range of thermal expansion and contraction of metal roof panels; S c is the deformation amount of the current metal roof panel; α is the linear expansion coefficient, a constant; k is the adjustment coefficient, a constant; t0 and L are the initial temperature and length of the panel when it is installed; [t min , t max ] is the temperature threshold range to be obtained.

4. The method for monitoring the health of a metal roof for a BIPV photovoltaic power station according to claim 1, characterized in that: The specific method of early warning of the drainage capacity of the metal roof gutter is: Based on the measured cross-sectional height and width of the drainage ditch, the actual water level of the drainage ditch is collected in real time; Combined with the unit rainfall intensity in the weather forecast, calculate the rainfall received by the drainage ditch; Based on the relevant theories of hydraulics, the drainage volume can be calculated through the height of the drainage ditch; According to the safe operation condition that the drainage volume of the metal roof is greater than or equal to the rainfall, the minimum height of the drainage gutter is calculated to obtain the safety threshold of the drainage capacity of the gutter; Calculate the difference between the drainage gutter height and the actual water level currently measured; The difference height is compared with the safety threshold to determine whether to issue a warning message on the health of the metal roof.

5. A metal roof health warning system for a BIPV photovoltaic power station, characterized in that: The method according to any one of claims 1 to 4 is adopted, wherein the system comprises: Data acquisition module, which collects metal roof panel deformation data, temperature data, wind data, rainfall data and drainage gutter data in real time when the metal roof is in operation; The data processing module calculates the thermal expansion and contraction temperature safety threshold of the metal roof panel, the theoretical value of the lateral deformation, and the theoretical value of the drainage capacity of the gutter according to the measured temperature data, the deformation of the metal roof panel, the wind data, the precipitation data, and the drainage gutter data; The safety threshold module has thermal expansion and contraction temperature safety thresholds, lateral deformation safety thresholds, and gutter drainage capacity safety thresholds; The early warning information release module compares the current temperature data, theoretical value of lateral deformation and theoretical value of gutter drainage capacity of the measured metal roof with the thermal expansion and contraction temperature safety threshold, lateral deformation safety threshold and gutter drainage capacity safety threshold in the safety threshold module. If at least one parameter in the measured data exceeds the corresponding set safety threshold, the metal roof health early warning information is released to the outside.

6. The metal roof health warning system for BIPV photovoltaic power station according to claim 5 is characterized in that: The data acquisition module includes a water level sensor, a temperature sensor, a distance sensor and a data collector; the water level sensor is installed in the gutter on the roof of the BIPV photovoltaic power station to measure the water level, the temperature sensor is installed on the metal roof panel to measure the temperature of the roof panel, and the distance sensor is installed in the wind load area on the metal roof to measure the deformation of the roof panel; the data collector communicates with the water level sensor, temperature sensor and distance sensor through an RS485 bus to obtain the measured data; the data collector is connected to the data processing module through a wireless transmission module.

Images