A method and system for detecting air leakage points in a high-rise building

Abstract

The application relates to a high-rise building air leakage position detection method and system, wherein the high-rise building air leakage position detection method comprises the following steps: sealing treatment is performed on a measured building; according to a set value of an indoor-outdoor pressure difference, air pressure supply is performed on the measured building, a thermal imaging image of an outer surface of the measured building corresponding to the set value of the indoor-outdoor pressure difference is obtained, and a temperature index reflection image is generated; temperature values corresponding to each pixel point in the temperature index reflection image are extracted based on time sequence, and indoor-outdoor pressure difference values corresponding to the time when the image is obtained are obtained; phase values of pressure changes and phase values of temperature changes of each pixel point are respectively fitted by obtaining the temperature values and the indoor-outdoor pressure difference values; and positions of pixel points with the same phase values are air leakage positions.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of building energy saving, in particular to a high-rise building air leakage position detection method and system. BACKGROUND

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

[0003] High-rise buildings have higher energy consumption than general buildings, which will make the equipment in the building consume more energy. In order to solve this problem, most high-rise buildings will optimize the thermal insulation performance of the envelope structure. With the increase of building height, the energy consumption caused by unorganized ventilation of the building gradually increases in the total energy consumption. Affected by the air tightness of the building envelope structure, the leaked air will take away heat and increase energy consumption. At the same time, air permeation will also affect the indoor air quality and the internal moisture transfer of the building envelope structure, thereby affecting the physical properties and service life of the building materials, and the integrity and durability of the building structure. SUMMARY

[0004] In order to solve the technical problems existing in the background art, the present application provides a high-rise building air leakage position detection method and system. After closing the doors and windows, ventilation openings and the like of the building, the building interior is pressurized and air supply is handled using the "blow door method". After the indoor and outdoor temperature difference and pressure difference meet certain requirements, an unmanned aerial vehicle carries an infrared thermal imager to take pictures of the outer surface of the building. After the shooting is completed, the obtained images are modeled and compared to find suspected air leakage positions.

[0005] In order to achieve the above purpose, the present application adopts the following technical solutions:

[0006] The first aspect of the present application provides a high-rise building air leakage position detection method, comprising the following steps:

[0007] Sealing treatment of the measured building;

[0008] According to the set value of the indoor and outdoor pressure difference, pressurized air supply is provided to the measured building, a thermal image of the outer surface of the measured building corresponding to the set value of the indoor and outdoor pressure difference is obtained, and a temperature index reflection map is generated;

[0009] Based on the time sequence, the temperature value corresponding to each pixel point in the temperature index reflection map is extracted, and the indoor and outdoor pressure difference value when the image is obtained is obtained. The phase value of pressure change and the phase value of temperature change of each pixel point are fitted respectively, and the position of the pixel point with the same phase value is the air leakage position.

[0010] After the location of the air leakage part is determined, isotherals are generated in the temperature index reflectogram under the condition that the indoor-outdoor pressure difference is minimum, the isotherals are marked based on the temperature setting value, and the area enclosed by the isotherals is the area of the air leakage part.

[0011] According to the number of pixel points in the area enclosed by the isotherals, the area of the air leakage part in the image is determined.

[0012] According to the ratio between the actual area of the building outer surface and the number of pixel points of the thermal imaging image as a coefficient, the actual area of the air leakage part is determined based on the obtained coefficient.

[0013] According to the actual area of the air leakage part, the air leakage part that needs to be repaired is determined and marked in the image.

[0014] The measured building is sealed, specifically: all doors, windows, vents, holes and holes in the measured building that contact the external environment are closed; the water supply and drainage system of the measured building is water sealed.

[0015] During the period of pressurized air supply into the measured building, the indoor-outdoor temperature difference is maintained to meet the set value.

[0016] The temperature index reflectogram is generated, specifically: the position information in the thermal imaging image is obtained, and the temperature index reflectogram is generated according to the obtained position information and the thermal imaging image after conversion.

[0017] In the temperature index reflectogram under the condition that the indoor-outdoor pressure difference is minimum, isotherals are generated, the isotherals are marked based on the temperature setting value, and the area enclosed by the isotherals is the area of the air leakage part, specifically:

[0018] In the temperature index reflectogram, isotherals are generated based on the set temperature gradient;

[0019] In the position overlapping with the air leakage part, the isotherals are marked based on the temperature setting value, and the area enclosed by the isotherals is the area of the air leakage part.

[0020] The second aspect of the present application provides a system required to implement the above-mentioned method, comprising:

[0021] A fan for pressurized air supply into the measured building;

[0022] A drone carrying an infrared thermal imager for obtaining an infrared image of the outer surface of the measured building;

[0023] An indoor-outdoor pressure difference meter and an indoor-outdoor temperature difference meter for obtaining the indoor-outdoor pressure difference and the indoor-outdoor temperature difference of the measured building;

[0024] The processing module is configured to generate a temperature index reflection map according to the image of the infrared thermal imager and the location of the unmanned aerial vehicle, and determine the location and area of the air leakage part according to the temperature index reflection map, the corresponding indoor and outdoor pressure difference, and the indoor and outdoor temperature difference.

[0025] Compared with the prior art, the above one or more technical solutions have the following beneficial effects:

[0026] 1. Infrared images are shot on the outer surface of the building, and the leakage position is determined according to the indoor and outdoor pressure difference and the temperature difference, which avoids the need for indoor detection to shoot each detection position one by one, greatly improving the efficiency.

[0027] 2. After determining the leakage position, the size of the leakage area is determined according to the proportion between the number of pixels in the shot image and the actual area of the building, which is conducive to mastering the actual air leakage situation of the building, and compared with the indoor detection method, the outdoor detection of the leakage area is more close to the actual situation.

[0028] 3. After the size of the leakage area is mastered, the leakage position that needs to be repaired can be determined according to the leakage area and the actual demand of the building, and the position to be repaired can be marked in the original image, which is convenient for subsequent optimization evaluation.

[0029] 4. The leakage position is determined by using the unmanned aerial vehicle to shoot on the outer surface of the building, which meets the actual detection demand of high-rise buildings. BRIEF DESCRIPTION OF DRAWINGS

[0030] The drawings accompanying the specification of this application form a part thereof, serve to provide further understanding of the application, and together with the description of the exemplary embodiments of the application and the explanation thereof serve to explain the application, and do not constitute improper limitations on the application.

[0031] Figure 1 is a schematic diagram of a high-rise building air leakage part detection method provided by one or more embodiments of the application;

[0032] Figure 2 is a schematic diagram of an indoor and outdoor pressure difference meter and an indoor and outdoor temperature difference meter installation provided by one or more embodiments of the application;

[0033] Figure 3 is a schematic diagram of a pressure gradient method provided by one or more embodiments of the application;

[0034] Figure 4 is a flow chart of an image splicing modeling processing process provided by one or more embodiments of the application;

[0035] Figure 5 is a schematic diagram of an image processing flow provided by one or more embodiments of the application;

[0036] In the figure: 1 - variable frequency pressure booster blower; 2 - unmanned aerial vehicle; 3 - infrared thermal imager; 4 - building to be measured; 5 - indoor and outdoor pressure difference meter; 6 - indoor and outdoor temperature difference meter. DETAILED DESCRIPTION

[0037] The application will be further described below with reference to the accompanying drawings and examples.

[0038] It should be noted that the following detailed description is exemplary in nature and is intended to provide further description of the application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0039] It should be noted that the terms used herein are only intended to describe specific embodiments and are not intended to limit exemplary embodiments according to the present application. As used herein, the singular form is intended to include the plural form unless the context clearly indicates otherwise, and it should also be understood that when the terms "comprise" and / or "include" are used in the specification, they refer to the presence of a feature, step, operation, device, component, and / or combinations thereof.

[0040] In the field of energy saving of high-rise buildings, the optimization of the thermal insulation performance of building envelopes has been sufficient, and the additional energy consumption caused by unorganized ventilation in buildings will increase with the increase of building height; at the same time, the air tightness of the building will also bring additional energy consumption, and the air leakage caused by the air tightness problem will carry away more energy as the building height increases; at the same time, air permeation will also affect the indoor air quality and the internal moisture transfer of the building envelope, thereby affecting the physical properties and service life of building materials, the integrity and durability of the building structure.

[0041] The following examples give a method and system for detecting air leakage points in high-rise buildings, which is a method theoretically applicable to all building air tightness detection to ensure the construction of ultra-low energy consumption buildings and ensure the air tightness requirements of buildings. At the same time, the detection method is also applicable to providing corresponding suggestions for energy-saving reconstruction of existing buildings.

[0042] The differential pressure method or "blower door method" is to use a blower to pressurize the air supply in the whole building, and to form an internal and external pressure difference in the whole building. This pressure difference will make air flow between the inside and outside through the air tightness defect site. When there is a temperature difference between the inside and outside, if the indoor temperature is higher than the indoor temperature, the temperature of the air tightness defect site will be higher than the temperature of the surrounding area; if the indoor temperature is lower than the outdoor temperature, the temperature of the air tightness defect site will be lower than the temperature of the surrounding area.

[0043] For a certain air penetration site, the air penetration amount will increase with the increase of the pressure difference on both sides, and its influence range will also gradually increase with the increase of the pressure difference. The range of the air tightness defect site showing the temperature different from the surrounding area will also change, so the pressure gradient method can be used, and the building surface temperature distribution can be quickly obtained by using an infrared thermal imager. By analyzing the changes of the building surface temperature distribution, the typical air penetration site of the building can be determined.

[0044] Example one:

[0045] As shown in Figures 1-2 , a high-rise building air leakage site detection method includes the following steps:

[0046] Install indoor and outdoor temperature difference meters 6 and indoor and outdoor pressure difference meters 5 in the measured building 4.

[0047] As shown in Figure 4 , seal the entire building, i.e. close all doors, windows and air conditioning system vents that contact the outside environment, and seal all suspected air leakage sites. Fill the water supply and drainage system of the measured building with water for water sealing, and use artificial methods to seal the pipes that cannot be water sealed. Use glass glue to stick polystyrene boards to seal the reserved holes of the measured building, and use waterproof film for sealing.

[0048] Turn on the variable frequency pressurized air blower 1 and observe the indoor and outdoor pressure difference meter 5. Adjust the speed of the variable frequency pressurized air blower 1, for example, to stabilize the indoor and outdoor pressure difference at about 30 Pa. Observe the indoor and outdoor temperature difference meter 6, and when the indoor and outdoor temperature difference reaches 5℃ or above, control the unmanned aerial vehicle 2 to carry the infrared thermal imager 3 to take the first photo of the outer surface of the measured building 4.

[0049] Import the Rjepg picture taken into the LocaSpaceViewer software to extract the POS information (latitude and longitude information, indicating the location information of the shooting location) therein. Import the Tiff format photo taken and the POS information into the Pix4Dmapper software, input the camera lens parameters for processing, and generate the first temperature index reflection map.

[0050] Adjust the variable frequency pressurized air blower 1 and observe the indoor and outdoor pressure difference meter 5. Adjust the speed of the variable frequency pressurized air blower 1, for example, to stabilize the indoor and outdoor pressure difference at about 50 Pa. Observe the indoor and outdoor temperature difference meter 6, and when the indoor and outdoor temperature difference reaches 5℃ or above, control the unmanned aerial vehicle 2 to carry the infrared thermal imager 3 to take the second photo of the outer surface of the measured building 4.

[0051] The Rjepg pictures taken are imported into the LocaSpaceViewer software to extract the POS information, and the taken Tiff format photos and the POS information are imported into the Pix4Dmapper software, the camera lens parameters are inputted for processing, and the second temperature index reflectance map is generated.

[0052] The variable frequency pressurized air blower 1 is adjusted, and the indoor and outdoor pressure difference meter 5 is observed, the speed of the variable frequency pressurized air blower 1 is adjusted, for example, the indoor and outdoor pressure difference is stabilized at about 70 Pa. The indoor and outdoor temperature difference meter 6 is observed, when the indoor and outdoor temperature difference reaches 5℃ or above, the unmanned aerial vehicle 2 carrying the infrared thermal imager 3 is controlled to take the outer surface of the measured building 4 for the third time.

[0053] The Rjepg pictures taken are imported into the LocaSpaceViewer software to extract the POS information, and the taken Tiff format photos and the POS information are imported into the Pix4Dmapper software, the camera lens parameters are inputted for processing, and the third temperature index reflectance map is generated.

[0054] The variable frequency pressurized air blower 1 is adjusted, and the indoor and outdoor pressure difference meter 5 is observed, the speed of the variable frequency pressurized air blower 1 is adjusted, for example, the indoor and outdoor pressure difference is stabilized at about 50 Pa. The indoor and outdoor temperature difference meter 6 is observed, when the indoor and outdoor temperature difference reaches 5℃ or above, the unmanned aerial vehicle 2 carrying the infrared thermal imager 3 is controlled to take the outer surface of the measured building 4 for the fourth time.

[0055] The Rjepg pictures taken are imported into the LocaSpaceViewer software to extract the POS information, and the taken Tiff format photos and the POS information are imported into the Pix4Dmapper software, the camera lens parameters are inputted for processing, and the fourth temperature index reflectance map is generated.

[0056] The variable frequency pressurized air blower 1 is adjusted, and the indoor and outdoor pressure difference meter 5 is observed, the speed of the variable frequency pressurized air blower 1 is adjusted, for example, the indoor and outdoor pressure difference is stabilized at about 30 Pa. The indoor and outdoor temperature difference meter 6 is observed, when the indoor and outdoor temperature difference reaches 5℃ or above, the unmanned aerial vehicle 2 carrying the infrared thermal imager 3 is controlled to take the outer surface of the measured building 4 for the fifth time.

[0057] The Rjepg pictures taken are imported into the LocaSpaceViewer software to extract the POS information, and the taken Tiff format photos and the POS information are imported into the Pix4Dmapper software, the camera lens parameters are inputted for processing, and the fifth temperature index reflectance map is generated.

[0058] As shown in Figure 3 The temperature of each pixel point in the five temperature index reflectance maps and the pressure value of the indoor and outdoor pressure difference meter 5 at the time of shooting are extracted according to the time sequence.

[0059] As shown in Figure 5 The pressure values are fitted using Fourier series to obtain the phase value of the pressure change, as shown in the following formula:

[0060] f(x)=a0+a1*cos(x*ω)+a2*sin(x*ω)

[0061] In this embodiment, the pressure values of 5 times are fitted to obtain the phase value of 1.571.

[0062] The temperature corresponding to each pixel point in the 5 groups of photos is fitted using Fourier series to obtain the phase value of the temperature change of each pixel point.

[0063] The phase value of the temperature change corresponding to each pixel point in the figure is compared with the phase value of the pressure change 1.571, and the position of the pixel point with the same phase value is determined as the typical air leakage position.

[0064] In the temperature index reflection map with a minimum pressure difference, such as 30 Pa, isotheral lines are generated, the temperature gradient of the isotheral line is 5%*indoor temperature, and the typical air leakage position is marked in the figure.

[0065] Find the isotheral line with the highest temperature*90% in the figure at the position overlapping the typical air leakage position, and mark the area enclosed by the isotheral line as the area of the typical air leakage position.

[0066] Determine the size of the typical air leakage position in the picture by the number of pixel points covered by the marked area of the typical air leakage position, such as 5184 pixel points corresponding to 1 square inch.

[0067] The ratio of the area of the picture obtained by the number of pixel points in the whole picture to the actual area of the building outer surface is taken as a coefficient to obtain the actual size of the typical air leakage position.

[0068] According to the actual demand, determine the typical air leakage position to be repaired and mark it. If the air leakage position with an area greater than 5 cm 2 is required to be repaired, set the air leakage position with an area greater than 5 cm 2 to be marked.

[0069] The above method uses a drone to take pictures on the outer surface of a building to determine the leakage position, determines the size of the leakage area according to the pixels in the photographed image, and marks the leakage position to be repaired according to the situation of the leakage area, avoiding the need to take pictures one by one for each detection position in indoor detection, greatly improving the efficiency, and the outdoor shooting method can improve the efficiency.

[0070] Example two:

[0071] A system for implementing the above method, comprising:

[0072] A fan for pressurized air supply into the measured building;

[0073] A UAV carrying an infrared thermal imager for acquiring infrared images of the outer surface of the measured building;

[0074] An indoor-outdoor pressure difference meter and an indoor-outdoor temperature difference meter for acquiring the indoor-outdoor pressure difference and the indoor-outdoor temperature difference of the measured building;

[0075] A processing module configured to generate a temperature index reflection map according to the images of the infrared thermal imager and the location of the UAV, and determine the location and area of the air leakage part according to the temperature index reflection map and the corresponding indoor-outdoor pressure difference and indoor-outdoor temperature difference.

[0076] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Various modifications and changes can be made by those skilled in the art without departing from the spirit and principles of the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for detecting air leakage points in high-rise buildings, characterized in that, Includes the following steps: The building under test needs to be sealed. Based on the set value of the indoor-outdoor pressure difference, pressurized air is supplied to the building under test, and a thermal image of the building's exterior surface corresponding to the set value of the indoor-outdoor pressure difference is acquired, and a temperature index reflectance map is generated. Specifically, the location information in the thermal image is acquired, and a temperature index reflectance map is generated based on the obtained location information and the converted thermal image. During the pressurized air supply to the building under test, the indoor-outdoor temperature difference is maintained at the set value. The UAV is equipped with an infrared thermal imager to acquire infrared images of the building's exterior surface. Based on the time sequence, the temperature values ​​corresponding to each pixel in the temperature index reflectance map are extracted, along with the indoor-outdoor pressure difference value at the time of image acquisition. The phase values ​​of pressure changes and temperature changes at each pixel are then fitted to obtain the phase values. Pixels with the same phase value are identified as air leak locations. After determining the location of the air leak location, isotherms are generated in the temperature index reflectance map at the minimum indoor-outdoor pressure difference. The isotherms are marked based on the temperature setpoint, and the closed area of ​​the isotherms is the area of ​​the air leak location. The area of ​​the air leak location in the image is determined based on the number of pixels within the closed area of ​​the isotherms.

2. The method for detecting air leakage points in high-rise buildings as described in claim 1, characterized in that, The actual area of ​​the air leak is determined based on the ratio between the actual area of ​​the building's exterior surface and the number of pixels in the thermal image.

3. The method for detecting air leakage points in high-rise buildings as described in claim 2, characterized in that, Determine the air leak locations that need repair based on their actual area and mark them on the image.

4. The method for detecting air leakage points in high-rise buildings as described in claim 1, characterized in that, The sealing treatment of the building under test includes: sealing all doors, windows, vents, holes and openings in the building that come into contact with the external environment; and water sealing the water supply and drainage system of the building under test.

5. The method for detecting air leakage points in high-rise buildings as described in claim 1, characterized in that, Isotherms are generated on the temperature index reflection map at the minimum indoor-outdoor pressure difference. These isotherms are marked based on the temperature setpoint. The closed area of ​​the isotherms represents the location of the air leak. Specifically: In the temperature index reflectance diagram, isotherms are generated based on a set temperature gradient; In the area overlapping with the air leak location, isotherms are marked based on the temperature setpoint, and the area where the isotherms close together is the area of ​​the air leak location.

6. A system for implementing the method according to any one of claims 1-5, characterized in that, include: Fans are used to pressurize and supply air into the building being tested; Indoor and outdoor differential pressure gauges and indoor and outdoor differential temperature gauges are used to obtain the indoor and outdoor pressure difference and indoor and outdoor temperature difference of the building being measured. The processing module is configured to generate a temperature index reflectance map based on the image from the infrared thermal imager and the location of the UAV. Based on the temperature index reflection diagram and the corresponding indoor-outdoor pressure difference and indoor-outdoor temperature difference, determine the location and area of ​​the air leak.

Images