An evaluation method for the radiative heat effect of the underlying surface

Abstract

The present invention discloses an evaluation method for the radiant heat effect of the underlying surface, comprising the following steps: S1: Obtain the hourly surface temperature of the underlying surface, the air temperature above the underlying surface, and the net radiation intensity of different underlying surfaces through on-site testing or theoretical calculation methods; S2: Calculate the radiant heat effect intensity μ of the underlying surface based on the hourly radiant heat effect intensity of the underlying surface during the day and at night; S3: Evaluate the radiant heat effect status of different underlying surfaces by calculating the radiant heat effect intensity μ of different underlying surfaces during the day and at night; S4: Analyze the feasibility of this evaluation index by analyzing the correlation between the hourly radiant heat effect intensity of the underlying surface, the hourly global horizontal radiation, and the hourly globe temperature. The present invention can quantitatively evaluate the radiant heat effect intensity of different underlying surfaces; at the same time, it also provides a method for evaluating the significance of the radiant heat effect of the underlying surface.

Description

Technical Field

[0001] The present invention relates to the technical field of urban thermal environment, and particularly relates to an evaluation method for the radiative heat effect of the underlying surface. Background Art

[0002] The rapid development of urbanization has led to the replacement of the original natural underlying surfaces such as grasslands and soils with artificial underlying surfaces such as cement, asphalt, and paving bricks, which are impervious. This has changed the radiation field of the urban underlying surface and the heat transfer process of the underlying surface, exacerbating urban thermal environment problems and further affecting the physical health and work and life of urban residents.

[0003] The underlying surface is divided into two categories: natural and artificial. Artificial underlying surfaces are widely used in urban construction due to their high strength and easy maintenance. After the underlying surface receives solar short-wave radiation and atmospheric counter-radiation, it will absorb a part of the solar short-wave radiation and atmospheric counter-radiation, and reflect the other part of the solar short-wave radiation and atmospheric counter-radiation into the atmosphere. At the same time, the radiative heat absorbed by the underlying surface causes the surface temperature of the underlying surface to rise, resulting in radiative heat transfer between the underlying surface and the surrounding environment in the form of long-wave radiation, causing more heat to accumulate on the underlying surface. Artificial underlying surfaces bring a large amount of radiative heat, increasing the outdoor thermal environment temperature and further affecting human health and building energy consumption. In current research on the radiation field and thermal environment of the underlying surface, most of them calculate the net radiation of the underlying surface to evaluate the strength of the radiation field of the underlying surface. The surface temperature and air temperature are manifestations of the strength of the radiation field of the underlying surface. Current research analyzes the thermal environment conditions of different underlying surfaces by separating these two factors, and does not analyze the degree of radiative heat effect of different underlying surfaces by combining the two.

[0004] Radiative heat accounts for the main part in the thermal effect process of the underlying surface, and the impact of radiative heat on the environment cannot be ignored. Different underlying surfaces have different radiative heat effects and different degrees of influence on air temperature, and different underlying surfaces have different degrees of influence on the thermal environment. Therefore, selecting a suitable evaluation method for the radiative heat of the underlying surface is of great significance for the research of the thermal environment of the underlying surface. Summary of the Invention

[0005] In order to overcome the above technical problems, the purpose of the present invention is to provide an evaluation method for the radiative heat effect of the underlying surface, which can quantitatively evaluate the intensity of the radiative heat effect of the underlying surface; at the same time, it also provides a method for evaluating the significance of the radiative heat effect of the underlying surface.

[0006] In order to achieve the above purpose, the technical solution adopted by the present invention is:

[0007] An evaluation method for the radiative heat effect of the underlying surface, comprising the following steps;

[0008] S1: Obtain the surface temperature T of the underlying surface, the air temperature T above the underlying surface a and the net radiation intensity E of the underlying surface through on-site testing or theoretical calculation methods;

[0009] S2: Calculate the evaluation indices of the radiative heat action of the underlying surface during the day μ d and at night μ n respectively, and then calculate the radiative heat action intensity μ of the underlying surface;

[0010] S3: Evaluate the radiative heat action status of the underlying surface by calculating the radiative heat action intensity μ of the underlying surface;

[0011] S4: Analyze the feasibility of the evaluation indices of the radiative heat effect of the underlying surface by analyzing the correlations among the radiative heat action intensity of the underlying surface, the total horizontal radiation, and the globe temperature.

[0012] In the said step S1, the on-site testing method and the instruments used for testing are as follows:

[0013] The total solar radiation and the short-wave radiation reflected by the underlying surface are tested using a KEO radiometer. When the KEO radiometer tests the total solar radiation, it is placed in an open and unobstructed position so that it can receive the solar short-wave radiation. The method for the KEO radiometer to test the reflected radiation is to place the solar radiometer horizontally facing the ground and measure the reflected radiation intensity of the underlying surface at a certain distance from the ground. The test period is 1 h. The long-wave radiation intensity emitted by the underlying surface is tested using a QTS-4 long-wave radiometer. The position of the instrument for measuring the long-wave radiation intensity is the same as that for measuring the reflected radiation intensity, and it is used to measure the radiation intensity in the long-wave band range. The test period is 1 h. The surface temperature of the underlying surface is measured using a four-channel thermocouple. The surface temperature of each type of underlying surface is measured using two channels, and then the average value of the two channels is calculated. The test period is 1 h. For the measurement of the air temperature above different underlying surfaces, the temperature block is placed at a position 1.1 m above the underlying surface and then wrapped with tinfoil to prevent the influence of solar radiation on the temperature block. The measurement period is 1 h.

[0014] In the said step S1, the method for theoretically calculating the net radiation of the underlying surface is as follows:

[0015] E = K ↑ + L ↑ - L ↓ (1)

[0016] In the formula: E is the net radiation intensity of the underlying surface, W / ㎡; K↑ is the amount of short-wave radiation reflected by the underlying surface per unit time and per unit area, W / ㎡; L↓ is the amount of atmospheric counter-radiation received by the underlying surface per unit time and per unit area, W / ㎡; L↑ is the amount of long-wave radiation emitted upward by the underlying surface per unit time and per unit area, W / ㎡;

[0017] The calculation method of the short-wave radiation intensity reflected by the underlying surface is as follows:

[0018] K ↑ = α·S0 (2)

[0019] Where: α is the short-wave reflectivity of the underlying surface; S0 is the total solar radiation intensity received by the underlying surface, W / ㎡;

[0020] The calculation method of the amount of atmospheric counter-radiation received by the underlying surface is as follows:

[0021]

[0022] Where: C b is the radiation constant of a black body, which is 5.67 W / (㎡·k 4 ); is the angular coefficient of the surface receiving radiation to the sky. For the roof plane, it can be taken as 1, and for the vertical wall surface, it can be taken as 0.5; T s is the equivalent sky temperature, K;

[0023] Regarding the calculation method of the equivalent sky temperature, some scholars have simplified it to:

[0024] T s ≈ T a + 273.15 - 6 (4)

[0025] Where: T a is the air temperature above the underlying surface, °C;

[0026] The long-wave radiation intensity upward from the underlying surface consists of two parts: the long-wave radiation intensity emitted by the underlying surface and the atmospheric counter-radiation reflected by the underlying surface; therefore, the long-wave radiation intensity upward from the underlying surface is:

[0027] L ↑ = εσ b (T + 273.15) 4 + (1 - ε)·L ↓ (5)

[0028] Where: is the Stefan-Boltzmann constant, also known as the black body radiation constant, T is the temperature of the underlying surface, °C.

[0029] In the above S2, the calculation of the hourly radiation heat action intensity of the underlying surface during the day and night is as follows:

[0030] The radiation heat action index of the underlying surface during the day μ d and at night μ n is calculated as follows:

[0031] μd =(T - T a ) * (K ↑ + L ↑ - L ↓ )(7:00 - 18:00) (6)

[0032] μ n =(T - T a ) * (L ↑ - L ↓ )(18:00 - 7:00)

[0033] The intensity μ of the radiant heat action of the underlying surface is as follows:

[0034]

[0035] In the formula, μ d is the intensity of the radiant heat action of the underlying surface during the day, °C·W / m², μ n is the intensity of the radiant heat action of the underlying surface at night, °C·W / m², μ is the intensity of the radiant heat action of the underlying surface, °C·W / m², μ is the intensity of the radiant heat action of the underlying surface, °C·W / m²; T is the surface temperature of the underlying surface, °C; Ta is the air temperature above the underlying surface, °C; K↑ is the amount of short-wave radiation reflected by the underlying surface per unit time and unit area, W / m²; L↓ is the amount of atmospheric counter-radiation received by the underlying surface per unit time and unit area, W / m²; L↑ is the amount of long-wave radiation emitted upward by the underlying surface per unit time and unit area, W / m²;

[0036] From equation (6), the intensity of the radiant heat action of the underlying surface during the day and at night can be obtained respectively;

[0037] From equation (7), the intensity of the radiant heat action of the underlying surface for the whole day can be obtained.

[0038] In step S3, calculate the intensity of the radiant heat action of the underlying surface and evaluate the difference in the radiant heat action status of the underlying surface.

[0039] In step S4, by calculating the hourly globe temperature above the underlying surface, the hourly horizontal total radiation intensity and the hourly radiant heat action intensity of the underlying surface, analyze the correlation between the horizontal total radiation intensity and the globe temperature received by the underlying surface, so as to verify the feasibility of this evaluation index. The globe temperature is measured or calculated on-site using a globe thermometer. The calculation method of the globe temperature is as follows:

[0040]

[0041] In the formula, T g is the globe temperature of the air above the underlying surface, °C; T a is the air temperature above the underlying surface, °C; S0 is the solar radiation intensity received by the underlying surface, W / m²; U is the wind speed above the underlying surface, m / s.

[0042] Advantages of the present invention:

[0043] The present invention provides an evaluation method for the radiative heat effect of urban underlying surfaces. First, through on-site testing or theoretical calculation, the surface temperature and air temperature of the underlying surface and the net radiation status of the underlying surface are determined; the evaluation index μ of the radiative heat effect of the underlying surface is calculated. The larger the value of this index, the stronger the radiative heat effect of the underlying surface. Taking asphalt and paving bricks as examples, the evaluation index of the radiative heat effect is calculated, and the radiative heat effects of the two underlying surfaces are evaluated. The correlations between the radiative heat indexes of asphalt and paving brick underlying surfaces and the total horizontal radiation and black globe temperature are analyzed, and their effectiveness is verified.

[0044] The present invention quantitatively analyzes the thermal effect of the radiative field of urban underlying surfaces and proposes an evaluation index for the intensity of the radiative heat effect of the underlying surface. The data used for calculation is simple to obtain and convenient to calculate, which helps to guide the optimal design of the thermal environment of the underlying surface.

[0045] The calculation of the present invention is simple and effective. The evaluation method is not affected by the type of the underlying surface. Only by knowing the net radiation intensity of the underlying surface and the difference between the surface temperature and air temperature of the underlying surface can the intensity of the radiative heat effect of different underlying surfaces be calculated. In addition, by using the evaluation index of the radiative heat effect to evaluate the significant degree of the radiative heat effect of the underlying surface, the differences in the radiative heat effects of different underlying surfaces can be analyzed. Description of the Drawings

[0046] Figure 1a It is a graph showing the changing trend of the net radiation intensity of different underlying surfaces in summer.

[0047] Figure 1b It is a graph showing the changing trend of the net radiation intensity of different underlying surfaces in winter.

[0048] Figure 2a It is a graph showing the changing trends of the surface temperature and air temperature of different underlying surfaces in summer.

[0049] Figure 2b It is a graph showing the changing trends of the surface temperature and air temperature of different underlying surfaces in winter.

[0050] Figure 3a It is a fitting graph showing the relationship between the total solar radiation intensity and the radiation evaluation index of the paving brick underlying surface in summer.

[0051] Figure 3b It is a fitting graph showing the relationship between the total solar radiation intensity and the radiation evaluation index of the asphalt underlying surface in summer.

[0052] Figure 4a It is a fitting graph showing the relationship between the total solar radiation intensity and the radiation evaluation index of the paving brick underlying surface in winter.

[0053] Figure 4b It is a fitting diagram of the relationship between the total solar radiation intensity and the radiation evaluation index of the asphalt underlying surface in winter.

[0054] Figure 5a It is a fitting diagram of the relationship between the globe temperature of the underlying surface in summer and the radiation evaluation index of the paving brick underlying surface.

[0055] Figure 5b It is a fitting diagram of the relationship between the globe temperature of the underlying surface in summer and the radiation evaluation index of the asphalt underlying surface.

[0056] Figure 6a It is a fitting diagram of the relationship between the globe temperature of the underlying surface in winter and the radiation evaluation index of the paving brick underlying surface.

[0057] Figure 6b It is a fitting diagram of the relationship between the globe temperature of the underlying surface in winter and the radiation evaluation index of the asphalt underlying surface.

[0058] Figure 7 It is a schematic diagram of the test instrument. Specific implementation manners

[0059] The present invention will be further described in detail below in conjunction with embodiments.

[0060] In this example, four types of underlying surfaces are selected to evaluate the radiative heat effect of the underlying surface type. The four types of underlying surfaces are relatively typical underlying surface types in the city. Among them, the concrete underlying surface, the asphalt underlying surface, and the paving brick underlying surface are artificial underlying surfaces with poor water permeability, and the grassland is a natural underlying surface with strong water permeability. Among the three artificial underlying surfaces, the reflectivity of the asphalt underlying surface is quite different from that of the other two underlying surfaces. Secondly, the paving bricks are laid in blocks, and the thickness of its underlying surface is different from that of the other underlying surfaces. The four underlying surfaces in the case are on-site in the Yanta Campus of Xi'an University of Architecture and Technology.

[0061] S1. Select the underlying surface for on-site testing:

[0062] In this example, four typical types of underlying surfaces are selected in the Yanta Campus of Xi'an University of Architecture and Technology for on-site testing. The test contents include the solar radiation received by the underlying surface, the short-wave solar radiation reflected by the underlying surface, the intensity of the atmospheric counter-radiation received by the underlying surface, the intensity of the long-wave radiation upward from the underlying surface, the surface temperature, the air temperature, etc. The test times are carried out in summer and winter respectively, from July 16, 2021 to July 22, 2021 and from March 6, 2022 to March 10, 2022. According to formula (1), the hourly net radiation intensity E of different underlying surfaces can be calculated. The hourly net radiation intensity of the underlying surface and the conditions of the surface temperature and air temperature of the underlying surface are as Figure 1a Figure 1b and Figure 2a Figure 2b .

[0063] The on-site test methods and the instruments used for the test are as follows:

[0064] The total solar radiation and the short-wave radiation reflected by the underlying surface are measured using a KEO radiometer. When measuring the total solar radiation with the KEO radiometer, it is placed in an open and unobstructed position so that it can receive the solar short-wave radiation. The method for measuring the reflected radiation with the KEO radiometer is to place the solar radiometer horizontally facing the ground at a certain distance from the ground to measure the intensity of the short-wave radiation reflected by the underlying surface, and the test period is 1 h. The intensity of the long-wave radiation emitted by the underlying surface is measured using a QTS-4 long-wave radiometer. The position of the instrument for measuring the long-wave radiation intensity is the same as that for measuring the reflected radiation intensity, and it can measure the radiation intensity in the long-wave band range, and the test period is 1 h. The surface temperature of the underlying surface is measured using a four-channel thermocouple. The surface temperature of each type of underlying surface is measured using two channels, and then the average value of the two channels is calculated, and the test period is 1 h. For measuring the air temperature above different underlying surfaces, the temperature block is placed at a position 1.1 m above the underlying surface, and then it is wrapped with tin foil to prevent the influence of solar radiation on the temperature block, and the measurement period is 1 h.

[0065] S2. Calculate the hourly radiative heat action intensity of different underlying surfaces during the day and at night according to formula (6), and then the radiative heat action intensity of different underlying surfaces can be calculated according to formula (7). The results are shown in Table 1:

[0066] Table 1 Radiative heat action intensity of different underlying surfaces

[0067]

[0068]

[0069] S3. Compare the radiative heat actions of different underlying surfaces in summer and winter to evaluate the differences in the radiative heat actions of different underlying surfaces:

[0070] As can be seen from Table 1, the intensity of radiative heat action on different underlying surfaces varies in different seasons. The intensity of radiative heat action on the underlying surface in summer is greater than that in winter, mainly because the solar radiation intensity in summer is greater than that in winter. The differences in radiative heat action on different underlying surfaces in different seasons are relatively large, and the degrees of influence on the surrounding environment are different. Among the four selected underlying surfaces, the order of the intensity of radiative heat action of the four underlying surfaces in summer from large to small is: paving brick underlying surface, concrete underlying surface, asphalt underlying surface, grassland underlying surface; the order of the intensity of radiative heat action of the four underlying surfaces in winter from large to small is: paving brick underlying surface, asphalt underlying surface, concrete underlying surface, grassland underlying surface. Whether in winter or summer, the radiative heat action of paving bricks is the strongest, and that of the grassland underlying surface is the smallest, with the concrete and asphalt underlying surfaces being the second. The intensity of radiative heat action of the grassland underlying surface is the smallest and is negative, mainly because the surface temperature of the underlying surface is lower than the air temperature above the underlying surface.

[0071] S4. Select two underlying surfaces (paving brick and asphalt underlying surfaces), and by calculating the hourly horizontal total radiation intensity received by the underlying surface and the hourly globe temperature above the underlying surface, analyze the relationship between the hourly horizontal total radiation intensity, the hourly globe temperature and the hourly radiative heat action of the underlying surface, and analyze the feasibility of this index;

[0072] Under the action of the solar horizontal total radiation, the underlying surface will absorb the solar short-wave radiation, causing the surface temperature of the underlying surface to rise. The surface will heat the air temperature in the form of sensible heat or latent heat. At the same time, the air temperature will rise under the action of solar radiation. The rise in air temperature mainly depends on the magnitude of the solar radiation intensity and the radiative heat action of different underlying surfaces on the air. Therefore, the horizontal total radiation intensity can reflect the degree of change in air temperature.

[0073] Temperature is a manifestation of the radiative heat action of the underlying surface. The globe thermometer exchanges radiative heat with the surrounding enclosure structure and convective heat with the surrounding air. When the heat in these two parts reaches equilibrium, the data measured by the thermometer is the globe temperature. The globe temperature can reflect the degree of radiative heat action of different underlying surfaces in terms of temperature.

[0074] Therefore, here the solar total radiation intensity received by the underlying surface and the globe temperature above the underlying surface are used to verify the feasibility of this evaluation index, and the correlation coefficient R 2 > 0.7, indicating that this evaluation index can reflect the intensity of radiative heat action of different underlying surfaces. The linear fitting relationships between the radiative heat action of different underlying surfaces in different seasons and the horizontal total radiation intensity and the globe temperature are as Figure 3a 、 Figure 3b 、 Figure 4a 、 Figure 4b 、 Figure 5a 、 Figure 5b, Figure 6a , Figure 6b , Figure 7 as shown in.

[0075] It can be seen from the figure that the correlations between the horizontal total radiation intensity of the summer paving bricks and asphalt underlying surfaces and the evaluation index are 0.79 and 0.78 respectively; the correlations between the globe temperatures of the air above the paving bricks and asphalt underlying surfaces and the evaluation index are 0.92 and 0.85 respectively. In winter, the correlations between the horizontal total radiation intensity of the paving bricks and asphalt underlying surfaces and the evaluation index are 0.73 and 0.75 respectively; the correlations between the globe temperatures of the air above the paving bricks and asphalt underlying surfaces and the evaluation index are 0.83 and 0.88 respectively. For different underlying surfaces in different seasons, there is a certain non-linear relationship between the radiant heat action intensity of the underlying surface and the horizontal total radiation intensity and globe temperature of the underlying surface, and the correlation R of the radiation evaluation index and the horizontal total radiation intensity 2 is above 0.7; the correlation R of the radiation evaluation index and the globe temperature 2 is above 0.8. Therefore, the radiant heat action index of the underlying surface has a certain feasibility. It can be seen from the figure that the non-linear relationships between the horizontal total radiation intensity of the paving bricks and asphalt underlying surfaces, the globe temperature and the radiant heat action evaluation index show the same changing trend. As the horizontal total radiation intensity and globe temperature of the underlying surface increase, the evaluation index of the radiant heat action of the underlying surface also increases, and the radiant heat action of the underlying surface increases.

[0076] In summary, the method for evaluating the radiant heat action of the underlying surface proposed by the present invention is simple and effective in calculation. The evaluation method is not affected by the type of the underlying surface. Only by knowing the net radiation intensity of the underlying surface and the difference between the surface temperature and air temperature of the underlying surface can the radiant heat action intensity of different underlying surfaces be calculated. In addition, using the radiant heat action evaluation index to evaluate the significant degree of the radiant heat effect of the underlying surface can analyze the differences in the radiant heat action of different underlying surfaces. At the same time, the case used in the present invention shows that the differences in the radiant heat action of different underlying surfaces on the environment are different, and the influencing degrees on the air temperature are inconsistent. For different underlying surfaces, it is particularly important to propose a suitable evaluation method for the radiant heat action of the underlying surface.

[0077] The above embodiments are only used to illustrate the technical concept and characteristics of the present invention, and the purpose is to enable those who are familiar with this technology to understand the content of the present invention and implement it accordingly, and cannot limit the protection scope of the present invention. All equivalent changes and modifications made to the scope of the claims of the present invention shall fall within the scope covered by the claims of the present invention.

Claims

1. An evaluation method for the action of radiant heat on the underlying surface, characterized in that, Including the following steps; S1: Obtain the surface temperature T of the underlying surface, the air temperature T above the underlying surface a and the net radiation intensity E of the underlying surface through on-site testing or theoretical calculation methods; S2: Calculate the intensity of the underlying surface radiative heat effect during the day, μ d , and at night, μ n . Then calculate the intensity of the underlying surface radiative heat effect, μ; S3: Evaluate the radiative heat effect of the underlying surface by calculating the radiative heat effect intensity μ of the underlying surface; S4: Analyze the feasibility of the evaluation index of the radiative heat effect of the underlying surface by analyzing the correlation between the radiative heat effect intensity of the underlying surface and the global horizontal radiation and the black globe temperature; In the above S2, the hourly radiative heat effect intensity of the underlying surface during the day and at night is calculated as follows: Underlying surface, daytime (7:00 - 18:00) μ d , nighttime (18:00 - 7:00) μ n The hourly radiative heat action intensity is calculated as follows: μ d = (T - T a ) * (K ↑ + L ↑ - L ↓ ) (6) μ n = (T - T a ) * (L ↑ - L ↓ ) The radiative heat effect intensity μ of the underlying surface is: where μ d is the radiation heat action intensity of the underlying surface during the day, in °C·W / m², and μ n is the radiation heat action intensity of the underlying surface at night, in °C·W / m². μ is the radiation heat action intensity of the underlying surface, in °C·W / m²; T is the surface temperature of the underlying surface, in °C; Ta is the air temperature above the underlying surface, in °C; K↑ is the amount of short-wave radiation reflected by the underlying surface per unit time and per unit area, in W / ㎡; L↓ is the amount of atmospheric counter-radiation received by the underlying surface per unit time and per unit area, in W / ㎡; L↑ is the amount of long-wave radiation emitted upward by the underlying surface per unit time and per unit area, in W / ㎡; The hourly radiative heat effect intensity of the underlying surface can be obtained from Equation (6); The radiative heat effect intensity of the underlying surface can be obtained from Equation (7).

2. The evaluation method for the radiant heat effect of the underlying surface according to claim 1, wherein In the above step S1, the on-site test method and the instruments used for the test are as follows: The global solar radiation and the short-wave radiation reflected by the underlying surface are measured using a KEO radiometer. When measuring the global solar radiation with the KEO radiometer, it is placed in an open and unobstructed position so that it can receive the solar short-wave radiation. The method for the KEO radiometer to measure the reflected radiation is to place the solar radiometer horizontally facing the ground and measure the reflected radiation intensity of the underlying surface at a certain distance from the ground. The test period is 1 h. The measurement of the long-wave radiation intensity emitted by the underlying surface uses a QTS-4 long-wave radiometer. The position of the instrument for measuring the long-wave radiation intensity is the same as that for measuring the reflected radiation intensity, which is used to measure the radiation intensity in the long-wave band range. The test period is 1 h. The measurement of the surface temperature of the underlying surface uses a four-channel thermocouple. The surface temperature of each type of underlying surface is measured using two channels, and then the average value of the two channels is calculated. The test period is 1 h. For the measurement of the air temperature above different underlying surfaces, the temperature block is placed at a position 1.1 m above the underlying surface and then wrapped with tinfoil to prevent the influence of solar radiation on the temperature block. The measurement period is 1 h.

3. The evaluation method for the radiant heat effect of the underlying surface according to claim 1, wherein, In the above step S1, the method for theoretically calculating the net radiation of the underlying surface is as follows: E = K ↑ + L ↑ - L ↓ (1) In the formula: E is the net radiation intensity of the underlying surface, in W / ㎡; K↑ is the amount of short-wave radiation reflected by the underlying surface per unit time and per unit area, in W / ㎡; L↓ is the amount of atmospheric counter-radiation received by the underlying surface per unit time and per unit area, in W / ㎡; L↑ is the amount of long-wave radiation emitted upward by the underlying surface per unit time and per unit area, in W / ㎡; The calculation method of the short-wave radiation intensity reflected by the underlying surface is as follows: K ↑ = α·S0(2) In the formula: α is the short-wave reflectivity of the underlying surface; S0 is the global solar radiation intensity received by the underlying surface, in W / ㎡; The calculation method of the amount of atmospheric counter-radiation received by the underlying surface is as follows: Where: C b is the radiation constant of a black body, which is 5.67 W / (m 2 ·K 4 ); is the angular coefficient of the surface receiving radiation with respect to the sky, which can be taken as 1 for the roof plane and 0.5 for the vertical wall surface; T s is the equivalent sky temperature, K; The calculation method for the equivalent sky temperature is: T s ≈T a +273.15 - 6(4) where: T a is the air temperature above the underlying surface, °C; The long-wave radiation intensity emitted upward by the underlying surface consists of two parts: the long-wave radiation intensity emitted by the underlying surface and the atmospheric counter-radiation reflected by the underlying surface; therefore, the long-wave radiation intensity emitted upward by the underlying surface is: L ↑ = εσ b (T + 273.15) 4 + (1 - ε)·L ↓ (5) Wherein: is the Stefan-Boltzmann constant, also known as the blackbody radiation constant, T is the temperature of the underlying surface, in °C.

4. The evaluation method for the radiant heat effect of the underlying surface according to claim 1, wherein, In the above S3, calculate the radiative heat effect intensity of different underlying surfaces and evaluate the differences in the radiative heat effect of different underlying surfaces.

5. The evaluation method for the radiant heat effect of the underlying surface according to claim 1, wherein In S4, by calculating the hourly black globe temperature above the underlying surface, the hourly horizontal global radiation intensity, and the hourly radiative heat action intensity of the underlying surface, the correlation between the horizontal global radiation intensity received by the underlying surface and the black globe temperature is analyzed, so as to verify the feasibility of this evaluation index. The black globe temperature is obtained by on-site measurement or calculation using a black globe thermometer. The calculation method of the black globe temperature is as follows: where, T g is the black globe temperature of the air above the underlying surface, °C; T a is the air temperature above the underlying surface, in °C; S0 is the solar radiation intensity received by the underlying surface, in W / m²; U is the wind speed above the underlying surface, in m / s.

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