Evaluation method for performance of reflective insulation coating for building exterior wall

Abstract

The invention discloses a method for evaluating the performance of a building exterior wall reflective insulation coating, which comprises the following steps of: a, manufacturing a standard reference building reflective insulation coating plate, and measuring corresponding spectral data; b, aiming at the standard reference building reflective insulation coating plate manufactured in the step a, calculating a characteristic index of the standard reference building reflective insulation coating plate as an evaluation standard of the reflective insulation coating performance; c, spectral data of the distribution area of the building exterior wall reflective insulation coating in the area to be detected are collected, corresponding characteristic indexes are calculated, and the calculation method of the characteristic indexes of the building exterior wall reflective insulation coating is the same as that in the step b; d, analyzing the characteristic indexes of the building exterior wall reflective insulation coating in the step c and the characteristic indexes of the standard reference building reflective insulation coating plate in the step b, and determining the performance of the building exterior wall reflective insulation coating in the to-be-detected area; the invention provides a basic technology and method for real-time and non-destructive evaluation of the performance of the building reflective insulation coating by means of a hyperspectral technical means.

Description

Technical Field

[0001] The invention relates to the technical field of performance evaluation of building reflective heat-insulating coatings, and in particular to a method for evaluating the performance of reflective heat-insulating coatings for building exterior walls. Background Art

[0002] As a new type of architectural coating, architectural reflective thermal insulation coating can reduce the building's energy consumption by enhancing the effective reflection of solar radiation energy by the building's exterior wall, reducing the absorption of solar radiation energy by the building's exterior wall, reducing heat accumulation on the exterior wall surface, and improving the stability of the hot and cold environment in the building. However, the research of domestic and foreign scholars mainly focuses on the components, structure, performance, and construction of building exterior wall thermal insulation coatings, and there are few studies on the performance loss and evaluation of architectural reflective thermal insulation coatings after construction. The evolution of coating performance in the time dimension is the key data for accurately evaluating the energy-saving effect of buildings.

[0003] At present, most of the coatings in China are evaluated before construction. However, after construction, architectural reflective thermal insulation coatings will be affected by uncontrollable factors such as solar radiation, precipitation, temperature changes, dust, etc., which will inevitably lead to a decrease in the performance of architectural reflective thermal insulation coatings on the exterior or interior walls of buildings. Therefore, timely performance evaluation of architectural reflective thermal insulation coatings has important practical significance and value. However, there are currently few evaluation methods for the performance of architectural reflective thermal insulation coatings for building exterior walls.

[0004] In order to solve the problem of evaluating the performance of building reflective thermal insulation coatings on building exterior walls after construction, the present invention proposes a method for evaluating the performance of building reflective thermal insulation coatings. The method uses spectral technology to construct an evaluation method for the performance of building reflective thermal insulation coatings with equivalent construction thickness based on the energy distribution range of solar radiation and the main functions of building reflective thermal insulation coatings, thereby providing basic technical and methodological support for the evaluation of building exterior wall coatings performance. Summary of the invention

[0005] In order to realize the evaluation of the performance of reflective thermal insulation coatings for building exterior walls by a new method, the present invention provides a method for evaluating the performance of reflective thermal insulation coatings for building exterior walls, which can realize accurate evaluation of the performance of reflective thermal insulation coatings for building exterior walls, thereby providing basic technology and method support for precise detection of building reflective thermal insulation coatings.

[0006] The detection principle of this patent is as follows: Building reflective thermal insulation coatings reflect the sun's radiation energy away from the building to maintain the stability of the temperature inside the building. The energy peak of solar radiation is mainly located in the visible light region, while the main reflection range of building reflective thermal insulation coatings is the visible light-partial near-infrared region. Based on the energy peak range of solar radiation and the main action range of building reflective thermal insulation coatings, the present invention proposes a method for evaluating the performance of building exterior wall reflective thermal insulation coatings, thereby providing basic technology and method support for the detection and evaluation of the performance of building reflective thermal insulation coatings.

[0007] The technical solutions adopted to achieve the above objectives are:

[0008] A method for evaluating the performance of reflective heat-insulating coatings for building exterior walls comprises the following steps:

[0009] a. Make a standard reference building reflective heat insulation coating board and measure the corresponding spectral data; the surface of the standard reference building reflective heat insulation coating board should be flat and smooth, with a thickness range of 0.01mm-2.5mm and a coating thickness interval of 0.05mm;

[0010] b. For the standard reference building reflective thermal insulation coating board produced in step a, calculate the characteristic index of the standard reference building reflective thermal insulation coating board as the evaluation standard for the performance of the reflective thermal insulation coating; the characteristic index of the standard reference building reflective thermal insulation coating board is marked as SVN sr_i , the spectral data in the range of 400nm-1150nm are selected for the calculation of characteristic indexes, and the spectral range of 400nm-1150nm is divided into two intervals [400, 780] and [781, 1150], and the characteristic indexes are calculated respectively. The calculation formula is as follows:

[0011]

[0012] In the formula, SVN sr_i_vis is the characteristic index of the standard coating plate with thickness i in the visible light region, R j_i is the reflectivity of a standard coating plate with a thickness of i in the visible light range [400-780] at a wavelength of jnm.

[0013]

[0014] In the formula, SVN sr_i_nir is the characteristic index of the standard coating plate with thickness i in the near infrared range, R j_i is the reflectivity of a standard coating plate with a thickness of i in the near-infrared range [781-1150] at a wavelength of jnm.

[0015] SVN sr_i =SVN sr_i_vis*0.65+SVN sr_i_nir *0.35

[0016] In the formula, SVN sr_i is the characteristic index of the standard coating plate with thickness i, SVN sr_i_vis is the characteristic index of the visible light region with thickness i, SVN sr_i_nir is the characteristic index of the near-infrared interval with thickness i;

[0017] c. Collect the spectral data of the distribution area of ​​the reflective thermal insulation coating on the exterior wall of the building in the test area, and calculate the characteristic index of the reflective thermal insulation coating on the exterior wall of the building in the test area, recorded as SVN tbt ; The calculation method of the characteristic index of the reflective thermal insulation coating on the exterior wall of the building in the test area is the same as step b;

[0018] d. Analyze the characteristic index of the reflective thermal insulation coating of the building exterior wall in the test area in step c and the characteristic index of the standard reference building reflective thermal insulation coating board in step b to determine the performance of the reflective thermal insulation coating of the building exterior wall in the test area;

[0019] d1. Set the characteristic index SVN of the reflective thermal insulation coating on the exterior wall of the building in the test area tbt SVN of standard reference plates with different thicknesses sr_i By comparison, determine the standard coating plate that is closest to the characteristic index of the reflective thermal insulation coating on the exterior wall of the building in the test area. Its thickness is recorded as SCBT. The comparison order is from large to small to determine SVN tbt After the interval is reached, the equivalent thickness ET is calculated. The larger the equivalent thickness, the better the performance of the building reflective thermal insulation coating. The calculation formula for the equivalent thickness ET is:

[0020]

[0021] Where ET is the equivalent thickness of the area to be tested, SCBT is the thickness of the standard coating plate that is closest to the characteristic index of the area to be tested, TI is the thickness interval of the standard coating plate, and SVN is sr_i SVN is the characteristic index of the standard coating plate with thickness i tbt It is the characteristic index of the measurement interval.

[0022] d2. According to the equivalent thickness ET in d1, determine the equivalent standard coating plate of the test area, and use the index data of the equivalent standard white plate as the index data of the test area.

[0023] Furthermore, the spectrum of the standard reference building reflective thermal insulation paint board in step a is collected using a ground object spectrometer with a spectral output resolution of 1 nm; when collecting the spectrum, the spectra of 15 different positions of the standard reference building reflective thermal insulation paint board should be collected, and the collection positions should be evenly distributed on the standard paint board. The average of the 15 spectra is taken as the final spectrum of the standard reference building reflective thermal insulation paint board, and the spectral data of the standard reference building reflective thermal insulation paint board is backed up and saved.

[0024] Furthermore, the collection points of the building exterior wall spectral data in step c should be evenly distributed in the area to be measured, each collection point measures a spectrum, the average of all collection points is taken as the final spectrum of the area to be measured, and the corresponding characteristic index parameters are calculated.

[0025] Furthermore, the index data of the equivalent standard whiteboard in step d2 includes solar reflectance and hemispherical emissivity.

[0026] The present invention has the following beneficial effects:

[0027] (1) The present invention provides a method for evaluating the performance of reflective thermal insulation coatings for building exterior walls. Relying on hyperspectral technology as the main means, the performance of reflective thermal insulation coatings for buildings is evaluated, and the detection accuracy of the performance of reflective thermal insulation coatings for building exterior walls is improved. The present invention not only has higher detection accuracy, better robustness and universality, but can effectively couple the available information of the spectrum, providing a basic technical method for the detection of the performance of reflective thermal insulation coatings for buildings, but also provides a basic technology and method for the real-time and non-destructive evaluation of the performance of reflective thermal insulation coatings for buildings, thereby helping to reduce energy consumption in urban buildings and save resources.

[0028] (2) The evaluation method provided by the present invention has strong flexibility and universality, and a corresponding evaluation scheme can be formulated according to the type of building reflective insulation strip coating, and has strong applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a flow chart of the method of the present invention;

[0030] Figure 2 It is the spectrum range diagram of solar radiation and the irradiance diagram of the earth's surface;

[0031] Figure 3 It is the distribution diagram of solar radiation energy;

[0032] Figure 4 The original spectral reflectance curve of the architectural reflective heat-insulating coating with different construction thicknesses in the present invention;

[0033] Figure 5 The characteristic index curve comparison diagram of the method of the present invention for verifying different points measured immediately after construction, one month after construction, and two months after construction;

[0034] Figure 6 The figures are comparison diagrams of equivalent thickness curves at different points 1 month and 2 months after construction for verifying the method of the present invention. DETAILED DESCRIPTION

[0035] The present invention is further described below in conjunction with the accompanying drawings.

[0036] like Figure 1 As shown, a method for evaluating the performance of reflective heat-insulating coatings for building exterior walls comprises the following steps:

[0037] a. Make a standard reference building reflective heat-insulating paint board and measure the corresponding spectral data; the surface of the standard reference building reflective heat-insulating paint board should be flat and smooth, with a thickness range of 0.01mm-2.5mm and a paint thickness interval of 0.05mm.

[0038] b. For the standard reference building reflective thermal insulation coating board produced in step a, calculate the characteristic index of the standard reference building reflective thermal insulation coating board as the evaluation standard for the performance of the reflective thermal insulation coating; the characteristic index of the standard reference building reflective thermal insulation coating board is marked as SVN sr_i ,like Figure 2 It is the spectrum range diagram of solar radiation and the irradiance diagram of the earth's surface. Figure 3 For the solar radiation energy distribution diagram, the spectral data in the range of 400nm-1150nm is selected in this patent for the calculation of characteristic indexes, wherein the spectral range of 400nm-1150nm is divided into two ranges [400, 780] and [781, 1150], and the characteristic indexes are calculated respectively, and the calculation formula is as follows:

[0039]

[0040] In the formula, SVN sr_i_vis is the characteristic index of the standard coating plate with thickness i in the visible light region, R j_i is the reflectivity of a standard coating plate with a thickness of i in the visible light range [400-780] at a wavelength of jnm.

[0041]

[0042] In the formula, SVN sr_i_nir is the characteristic index of the standard coating plate with thickness i in the near infrared range, R j_i is the reflectivity of a standard coating plate with a thickness of i in the near-infrared range [781-1150] at a wavelength of jnm.

[0043] SVN sr_i =SVN sr_i_vis *0.65+SVN sr_i_nir*0.35

[0044] In the formula, SVN sr_i is the characteristic index of the standard coating plate with thickness i, SVN sr_i_vis is the characteristic index of the visible light region with thickness i, SVN sr_i_nir is the characteristic index of the near-infrared interval with thickness i.

[0045] c. Collect the spectral data of the distribution area of ​​the reflective thermal insulation coating on the exterior wall of the building in the test area, and calculate the characteristic index of the reflective thermal insulation coating on the exterior wall of the building, recorded as SVN tbt ; The calculation method of the characteristic index of the building exterior wall reflective thermal insulation coating is the same as step b.

[0046] d. Analyze the characteristic index of the building exterior wall reflective insulation coating in step c and the characteristic index of the standard reference building reflective insulation coating board in step b to determine the performance of the building exterior wall reflective insulation coating in the test area;

[0047] d1. Set the characteristic index SVN of the reflective thermal insulation coating on the exterior wall of the building in the test area tbt SVN of standard reference plates with different thicknesses sr_i Compare and determine the standard coating plate that is closest to the characteristic index of the test area. Its thickness is recorded as SCBT. The comparison order is from large to small to determine SVN. tbt After the interval is reached, the equivalent thickness ET is calculated. The larger the equivalent thickness, the better the performance of the building reflective thermal insulation coating. The calculation formula for the equivalent thickness ET is:

[0048]

[0049] Where ET is the equivalent thickness of the area to be tested, SCBT is the thickness of the standard coating plate that is closest to the characteristic index of the area to be tested, TI is the thickness interval of the standard coating plate, and SVN is sr_i SVN is the characteristic index of the standard coating plate with thickness i tbt It is the characteristic index of the measurement interval.

[0050] d2. According to the equivalent thickness ET in d1, determine the equivalent standard coating board in the test area, and use the index data of the equivalent standard white board as the index data of the test area. In this way, the performance of the reflective heat insulation coating on the building exterior wall can be effectively evaluated by using the index data of the equivalent standard white board as a reference.

[0051] Preferably, the spectrum of the standard reference building reflective thermal insulation paint board in step a is collected using a ground object spectrometer with a spectral output resolution of 1 nm; when collecting the spectrum, the spectra of 15 different positions of the standard reference building reflective thermal insulation paint board should be collected, and the collection positions should be evenly distributed on the standard paint board. The average of the 15 spectra is taken as the final spectrum of the standard reference building reflective thermal insulation paint board, and the spectral data of the standard reference building reflective thermal insulation paint board is backed up and saved.

[0052] Preferably, the collection points of the building exterior wall spectral data in step c should be evenly distributed in the area to be measured, each collection point measures a spectrum, the average of all collection points is taken as the final spectrum of the area to be measured, and the corresponding characteristic index parameters are calculated.

[0053] Preferably, the index data of the equivalent standard whiteboard in step d2 includes solar reflectance and hemispherical emissivity.

[0054] like Figure 4 As shown, it is the original spectral reflectance of architectural reflective thermal insulation coatings with different construction thicknesses. Generally, it is greater than 450nm band. In the same band, the smaller the thickness, the lower the spectral reflectance.

[0055] like Figure 5 As shown, the ordinate is the characteristic index value, and the higher the characteristic index value, the better the performance of the building reflective thermal insulation coating. The abscissa is the sample point number, which only indicates the sample point number. The characteristic index curves measured directly after construction, one month after construction, and two months after construction in the figure show that the performance of the coating reflective thermal insulation coating decreases with time, which is consistent with the actual situation of the coating performance. This shows that the performance evaluation method of the building exterior wall reflective thermal insulation coating provided by the present invention has strong practicality.

[0056] like Figure 6 As shown, the ordinate is the equivalent thickness. The larger the equivalent thickness, the better the performance of the building reflective thermal insulation coating. The abscissa is the sample point number, which only indicates the sample point number. The equivalent thickness curves after 1 month of construction and 2 months of construction in the figure show that the performance of the reflective thermal insulation coating decreases with time, which is consistent with the actual performance of the coating. This shows that the performance evaluation method of the building exterior wall reflective thermal insulation coating provided by the present invention has strong practicality.

[0057] This embodiment does not impose any formal restrictions on the shape, material, structure, etc. of the patent of the present invention. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the patent of the present invention shall fall within the protection scope of the technical solution of the patent of the present invention.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some of the technical features therein by equivalents, but these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for evaluating the performance of reflective thermal insulation coatings for building exterior walls, characterized in that: include: a. Make standard reference building reflective heat insulation coating panels and measure the corresponding spectral data; The surface of the standard reference building reflective heat insulation coating board should be flat and smooth, with a thickness range of 0.01mm-2.5mm and a coating thickness interval of 0.05mm; b. For the standard reference building reflective thermal insulation coating board produced in step a, calculate the characteristic index of the standard reference building reflective thermal insulation coating board as the evaluation standard for the performance of the reflective thermal insulation coating; the characteristic index of the standard reference building reflective thermal insulation coating board is marked as SVN sr_i , the spectral data in the range of 400nm-1150nm are selected for the calculation of characteristic indexes, and the spectral range of 400nm-1150nm is divided into two intervals [400,780] and [781,1150], and the characteristic indexes are calculated respectively. The calculation formula is as follows: In the formula, SVN sr_i_vis is the characteristic index of the standard coating plate with thickness i in the visible light region, R j_i is the reflectivity of a standard coating plate with a thickness of i in the visible light range [400-780] at a wavelength of jnm. In the formula, SVN sr_i_nir is the characteristic index of the standard coating plate with thickness i in the near infrared range, R j_i is the reflectivity of the standard coating plate with thickness i in the near infrared range [781-1150] at a wavelength of jnm; SVN sr_i =SVN sr_i_vis *0.65+SVN sr_i_nir *0.35 In the formula, SVN sr_i is the characteristic index of the standard coating plate with thickness i, SVN sr_i_vis is the characteristic index of the visible light region with thickness i, SVN sr_i_nir is the characteristic index of the near-infrared interval with thickness i; c. Collect the spectral data of the distribution area of ​​the reflective thermal insulation coating on the exterior wall of the building in the test area, and calculate the characteristic index of the reflective thermal insulation coating on the exterior wall of the building in the test area, recorded as SVN tbt ; The calculation method of the characteristic index of the reflective thermal insulation coating on the exterior wall of the building in the test area is the same as step b; d. Analyze the characteristic index of the reflective thermal insulation coating of the building exterior wall in the test area in step c and the characteristic index of the standard reference building reflective thermal insulation coating board in step b to determine the performance of the reflective thermal insulation coating of the building exterior wall in the test area; d1. Set the characteristic index SVN of the reflective thermal insulation coating on the exterior wall of the building in the test area tbt SVN of standard reference plates with different thicknesses sr_i By comparison, determine the standard coating plate that is closest to the characteristic index of the reflective thermal insulation coating on the exterior wall of the building in the test area. Its thickness is recorded as SCBT. The comparison order is from large to small to determine SVN tbt After the interval is reached, the equivalent thickness ET is calculated. The larger the equivalent thickness, the better the performance of the building reflective thermal insulation coating. The calculation formula for the equivalent thickness ET is: Where ET is the equivalent thickness of the area to be tested, SCBT is the thickness of the standard coating plate that is closest to the characteristic index of the area to be tested, TI is the thickness interval of the standard coating plate, and SVN is sr_i SVN is the characteristic index of the standard coating plate with thickness i tbt It is the characteristic index of the measurement interval; d2. According to the equivalent thickness ET in d1, determine the equivalent standard coating plate of the test area, and use the index data of the equivalent standard white plate as the index data of the test area.

2. The method for evaluating the performance of a reflective heat-insulating coating for a building exterior wall according to claim 1, characterized in that: In the step a, the spectrum of the standard reference building reflective thermal insulation paint board is collected using a ground object spectrometer with a spectral output resolution of 1 nm; when collecting the spectrum, the spectra of 15 different positions of the standard reference building reflective thermal insulation paint board should be collected, and the collection positions should be evenly distributed on the standard paint board. The average of the 15 spectra is taken as the final spectrum of the standard reference building reflective thermal insulation paint board, and the spectral data of the standard reference building reflective thermal insulation paint board is backed up and saved.

3. A method for evaluating the performance of a reflective heat-insulating coating for a building exterior wall according to claim 2, characterized in that: The collection points of the building exterior wall spectral data in step c should be evenly distributed in the area to be measured, each collection point measures a spectrum, the average of all collection points is taken as the final spectrum of the area to be measured, and the corresponding characteristic index parameters are calculated.

4. A method for evaluating the performance of a reflective heat-insulating coating for a building exterior wall according to claim 3, characterized in that: The index data of the equivalent standard whiteboard in step d2 include solar reflectance and hemispherical emissivity.

Images