Classification of environmental conditions—Environmental conditions appearing in nature—Solar radiation and temperature
Some standard content:
ICS19.020
National Standard of the People's Republic of China
GB/T4797.4—2019/IEC60721-2-4:2002 replaces GB/T1797.42006
Classification of environmental conditions
Natural environmental conditions
Solar radiation and temperature
Classification of environmental conditions-Environmental conditionsappearing in nature-Solar radiation and temperature(IEC 60721-2-4:2002.Classification of cnvironmcntal conditionsPart 2-4:Environmental conditions appearing in nature-Solarradiation andtemperature.IDTy2019-12-10Release
State Administration for Market Regulation
National Administration of Standardization
2020-07-01Implementation
GB/T 4797.4—2019/IEC 60721-2-4:2002 Before
Solar radiation process
Total radiation level
6 Minimum estimate of nighttime atmospheric radiation
Appendix A (informative appendix) World distribution of daily total irradiance Appendix NA (informative appendix)
Appendix NB (informative appendix)
References:
Monthly average total Ⅱ irradiation and annual average total Ⅱ irradiation in major regions of the country Solar radiation intensity in my country
Figure "Popular radiation in a clear sky
Figure 2 Electromagnetic spectrum of radiation from the sun and the earth's surface. Figure A.16 Monthly average relative total irradiation...
Figure A, 212 Monthly average pole-to-pole total radiation
Annual average relative total radiation
Table 1 Typical peak values of total radiation
Table A.1. Average daily total radiation outside the Earth.
Table VA.1 Monthly average daily total radiation and annual average daily total radiation for major cities in China Table N3.1 Levels of solar radiation intensity in my country 10
GB/T4797 includes the following parts:
GB/T4797.4—2019/1EC60721-2-4:2002-GB/T4797.1 Classification of environmental conditions Natural environmental conditions Temperature and humidity—GB/T 4797.2
Classification of environmental conditions, natural environmental conditions air pressure; GB/T 4797.3
GB/T 4797.4
GB/T 4797.5
Electrical and electronic products natural environmental conditions, biology: environmental conditions classification natural environmental conditions solar radiation and temperature: environmental conditions classification
natural environmental conditions precipitation and wind;
5 Environmental conditions classification natural environmental conditions dust, sand, salt spray; GB/T 4797.6
GB/T 4797.7
Electrical and electronic products environmental conditions classification natural environmental conditions earthquake vibration and shock, this part is (Part 1 of GB/T1797. This part was drafted according to the rules given in GB/T1.12009. This part replaces GB/T4797.4-2006 "Electrical and electronic products natural environmental conditions solar radiation and temperature". Compared with GB/T4797.4-2006, this part has the following major changes: the name of the standard has been changed to "Environmental conditions classification natural environmental conditions solar radiation and temperature"; the informative appendix NA "National major areas of the monthly average total radiation and annual average total radiation" has been added; the original informative appendix NA has been changed to informative appendix NB. This part uses the translation method equivalent to IEC60721-2-4: 2002 "Environmental conditions classification part 2-4: natural environmental conditions solar radiation and temperature". This part mainly makes the following editorial changes: In order to unify with the existing standard series in my country, this part The name of the classification of environmental conditions was changed to "Natural environmental conditions: Solar radiation and temperature";
Informative Appendix NA\Monthly average daily total radiation in major areas of the country and annual average daily total radiation" was added; Factory informative Appendix ΛB\Solar radiation intensity in my country" was added. This part was proposed and submitted by the National Technical Committee for Standardization of Environmental Conditions and Environmental Testing for Electrical and Electronic Products (SAC/TC8). The drafting units of this part include China Electric Power Research Institute Co., Ltd., Sichuan Renxue, Fujian New Energy Hai1 Wind Power Research and Development Center Co., Ltd.,
The main drafters of this part include Gong Jun, Tao Youji, Li Guangxian, Ye Lin, and Huang Xiangshi. The previous versions of the standard replaced by this part are: -GB/T 4797.4—1989, GB/T 4797.4—2006.1 Scope
GB/T 4797.4—2019/IEC 60721-2-4:2002 Classification of environmental conditions Natural environmental conditions
Solar radiation and temperature
This part of CB/T4797 summarizes the solar radiation areas into several types, mainly providing some background material for selecting the appropriate solar radiation severity for product applications: Except for areas with an altitude of more than 5000m. This part covers various terrains. When selecting the severity of solar radiation for a product, the values given in IEC 60721-1 should be used. 2 Purpose
Specifies the severity of solar radiation to which the product is subjected during storage, transportation and use: 3 Overview
Solar radiation affects electrical products primarily by heating the material and the environment and by causing photochemical degradation of the material: The ultraviolet portion of solar radiation causes photochemical degradation of most polymer materials, affects the elasticity and plasticity of some rubbers and plastics, and optical glass may become cloudy.
Solar radiation can cause paint, textiles, paper, etc. to fade. In some cases, color may be important, such as the color coding of components. Heating of materials is the most important effect of solar radiation exposure. The severity of solar radiation is related to the radiation power intensity or irradiance of the surface, expressed in W/m
The temperature reached by an object subjected to solar radiation depends primarily on the ambient air temperature, the solar radiation energy, and the angle of incidence of the solar radiation. Other factors, such as wind and the thermal conductivity of the mounting, may also be important. The absorption coefficient a of the outer surface of the blade to the solar spectrum is also quite important.
Virtual air temperature (under steady-state conditions, it has the same temperature as the surface of the object, and can be defined by combining the actual air temperature and the amount of solar radiation E:
The approximate estimate can be obtained by the following equation: t,=t+a.·?
The coefficient h is the thermal conductivity of the surface, in W/(m:℃), including the surrounding thermal radiation, as well as the heat conduction and convection caused by the mountain breeze. The absorption coefficient ", depends on the color, reflectivity and conductivity of the surface. The values for a clear sky are as follows:
a.-0.7:h.-20W/(m2·\C);E-900W/m. The overheating temperature caused by solar radiation is approximately)". It can be seen that a 10% error in the estimation of solar radiation intensity will not affect the temperature by more than 5°C. Therefore, there is no need to accurately classify the severity of solar radiation, and the influence of other small factors is ignored here. The thermal effect is mainly caused by short-term high-intensity solar radiation. For example, the solar radiation in a cloudless car is given in Table 1. In order to determine the low temperature of products exposed at night, it is also necessary to determine the lowest possible atmospheric radiation on a clear night. Figure 丨 gives some values:
GB/T4797.4—2019/IEC60721-2-4:2002300
4 Physical process of solar radiation
——20
Extremely humid air
Extremely dry air
Atmospheric temperature 2m above the ground level/
Figure 1 Atmospheric radiation in a clear night sky
The electromagnetic radiation from the sun to the earth covers a relatively wide spectrum from ultraviolet to near infrared: the energy reaching the earth's surface is concentrated in 0.3um~4um. There is a maximum value at 0.5um in visible light. The typical spectrum is shown in Figure 2. Note:
【（-g）
0.51.02.0
GB/T 4797.4—2019/1EC 60721-2-4:2002 Infrared
Human (external solar radiation. The black body with a temperature of 6000K is represented (1.60kW/m); extra-atmospheric solar radiation (1.37kW/m):
Direct solar radiation from the ground perpendicular to the direction of the vehicle (for example, 0,9kw/m2): The maximum solar radiation from the earth (for example 0.1CkW/m\): Water vapor and: Carbon dioxide absorption band:
Oxygen and ozone absorption;
The radiation of a black body with a temperature of 300K (0.47kW/1m): The thermal radiation of the earth (for example 0.07kW/m\). 50:100
Wavelength/um
Figure 2 The electromagnetic spectrum of radiation from the sun and the earth's surface At the average distance from the sun to the earth, the amount of solar radiation received per unit area of the sunlight outside the vertical atmosphere is called the solar constant. The value is about 1.37kw/m
Almost 99% of the solar radiation energy comes from wavelengths below 4μm, and most of the solar radiation below 0.3μm is absorbed by the atmosphere and does not reach the ground. In the process of passing through the atmosphere, due to the presence of particles and gases, further absorption and scattering will occur. The scattering of the indirect solar radiation in the atmosphere will cause scattering in the sky. Therefore, the energy received at a certain place on the earth is the sum of the direct solar radiation and the scattered radiation, which is defined as the total radiation. From the perspective of thermal effects, it is this sum that is of concern, so the levels given in this section are related to the total radiation. 5 Total radiation level
5.1 Maximum level
The maximum level of total radiation on a clear day occurs at noon. In a cloudless sky, the maximum value of the energy received by a surface perpendicular to the direct solar radiation depends on the total amount of particles, ozone and water vapor in the atmosphere. The values vary greatly in different latitudes and climate types. At noon, the water vapor content is about 1cm, the ozone content is 2mm, and the aerosol is 3-0.05. H, where 3 is the Angstrom turbidity coefficient, 3
GB/T 4797.4—2019/IEC 60721-2-4:2002, the energy received by a surface perpendicular to the direct solar radiation can reach 1120w/m For flat areas far from industrial areas and urban areas, when the solar radiation angle exceeds 60°, 1120W/m2 is representative to a certain extent: Note: The water vapor content in the vertical volume of the atmosphere is measured by the corresponding precipitation height cII. Similarly, the oxygen content is measured by the corresponding ozone height at standard temperature and pressure. The scattering and absorption of aerosol particles are expressed by the β Ångström turbidity coefficient, that is, the extinction distance of single-wavelength radiation with a wavelength of 1m in the atmosphere.
Direct solar radiation decreases with increasing air turbidity. In industrial and humid hot and desert areas, the particle density in the air is higher and the turbidity is relatively high. The air turbidity in urban areas is also relatively high. It is lower in mountainous areas. Table 1 gives the recommended maximum values of total radiation received by the surface of the vertical direct solar radiation at noon without clouds. During the hours of noon, this value only changes by a few percentage points, so it can represent the situation of a few hours in a certain period of time. Table 1 Typical peak values of total radiation
Subhumid heat and desert
Large cities
5.2 Monthly and annual averages of total solar radiation Flatland
Unit: watt per square meter
The thermal effect of solar radiation on the surface usually depends on the short-term radiation near noon. However, the photochemical reaction is related to the integral of the irradiation intensity over time, that is, the irradiation amount. For the purpose of comparison, the irradiation amount is the most commonly used data. In December, due to the long duration of light, the monthly average total irradiation near the South Pole can reach 10.8 kWh/m, and the area outside the South Pole is about 8.4 kWh/m
The maximum annual average daily total irradiation reaches 6.6 kWh/m, which mainly occurs in desert areas. 5.3 Synchronous values of maximum temperature and solar radiation The minimum value of the air turbidity coefficient is measured in cold air. Therefore, the values listed in Table 1 will not appear when the temperature reaches the highest. It can be assumed that at the highest overflow given by IEC60721-2-1, the total radiation will not exceed 80% of that given in Table 1. The distribution of the total daily radiation in the world and my country
IFor the distribution of total radiation, see Appendix A, Appendix NA, Appendix NB6Minimum value of atmospheric radiation at night
On a cloudless night, the atmospheric radiation is very low. The surface temperature of objects exposed at night is lower than the temperature of the surrounding atmosphere. The theoretical thermodynamic temperature T when the object reaches equilibrium with the atmospheric radiation is given by the Boltzman law: (A)
Wu Zhong:
Stefan-Boltzman constant. 5.67X10-8 W/(m*K');a
AAtmospheric radiation, in watts per square meter (W/n) (see Figure 1). In practice, the temperature will be higher due to heat conduction, convection and condensation of water vapor. On a clear night, the temperature of an exposed horizontal surface insulated from the ground can reach 11°C, while the air temperature is 0°C. The relative humidity is close to 100%.
Figure 1 shows the atmospheric radiation of night air as a function of the atmospheric temperature at 2m above the ground. On a clear night, the relative humidity is usually very high:
Appendix A
(Informative Appendix)
GB/T 4797.4—2019/1EC 60721-2-4:2002 World distribution of daily total radiation exposure
Figure A.1 Figure A.2 and Figure A.8 show relative total radiation exposure (June, December and annual average values) measured by satellite (see Note 1). Relative total radiation exposure is defined as the ratio of the total radiation exposure measured on the Earth's surface to the total radiation exposure outside the Earth (i.e. the solar radiation exposure outside the atmosphere in a plane perpendicular to the solar axis). In order to obtain the daily average total radiation exposure on the Earth's surface, the white fraction marked on the figure is multiplied by the daily average total radiation exposure outside the Earth. The value is given as a number for geographical latitude, see Table A.1. Note 1: Reference document for data source:
(.Maior et al.: World map of relative total solar radiation. World Meteorological Organization. Technical Note No. 172 Annex, WM0-No. 5570 , Geneva (1987). NOTE 2: The value of the daily irradiance in kWh/m2 is determined by averaging the monthly and annual irradiance values in MJ/m2. For example, the monthly irradiance value for June is divided by 30. For December by 31. For the annual irradiance value, it is divided by 365. Example:
This example shows how to determine the average daily total solar radiation in June at the southern tip of the California Peninsula. From the point in Figure A.1 (at about 23 degrees north latitude) around the 60% isotropic line, the percentage passing through this point is estimated to be 62%. According to Table A.1, the estimated value for the June total solar radiation at 23 degrees north latitude is 11.16 kWh/m2. Multiplying this value by the above ratio, the average daily total solar radiation is about 6.9 kh/m2. The average daily total solar radiation outside the Earth
is in "watt-hours per square meter
GB/T 4797.4—2019/IEC 60721-2-4:2002 Latitude
Table A.1 (continued)
Unit is kilowatt-hour per square meter
GB/T 4797.4—2019/IEC 60721-2-4:20029
GB/T 4797.4—2019/IEC 60721-2-4:2002 Figure
GB/T 4797.4—2019/1EC 60721-2-4:2002E2002 The energy received by a surface perpendicular to the direct solar radiation can reach 1120 W/m2. For flat land far away from industrial areas and urban areas, when the solar radiation angle exceeds 60°, 1120 W/m2 is representative to a certain extent: Note: The water vapor content in the vertical volume of the atmosphere is measured by the corresponding precipitation height cII. Similarly, the oxygen content is measured by the corresponding height of ozone at standard temperature and pressure. The scattering and absorption of aerosol particles are expressed by the β Angstrom turbidity coefficient, that is, the extinction distance of single-wavelength radiation with a wavelength of 1 m in the atmosphere.
Direct solar radiation decreases with the increase of air turbidity. In industrial and humid hot and desert areas, the particle density in the air is higher and the turbidity is relatively high. The air turbidity in urban areas is also relatively high. It is lower in mountainous areas. Table 1 gives the recommended maximum values of total radiation received by a surface perpendicular to direct solar radiation at noon without clouds. In a few hours at noon, this value only changes by a few percentage points, so it can represent the situation in a few hours in a certain period of time. Table 1 Typical peak values of total radiation
Subhumid heat and desert wwW.bzxz.Net
Large cities
5.2 Monthly and annual averages of total solar radiation Flatland
Unit: watt per square meter
The thermal effect of solar radiation on the surface usually depends on the short-term radiation near noon. However, the photochemical reaction is related to the integral of the irradiation intensity over time, that is, the irradiation amount. For the purpose of comparison, the irradiation amount is the most commonly used data. In December, due to the long duration of light, the monthly average total irradiation near the South Pole can reach 10.8 kWh/m, and the area outside the South Pole is about 8.4 kWh/m
The maximum annual average daily total irradiation reaches 6.6 kWh/m, which mainly occurs in desert areas. 5.3 Synchronous values of maximum temperature and solar radiation The minimum value of the air turbidity coefficient is measured in cold air. Therefore, the values listed in Table 1 will not appear when the temperature reaches the highest. It can be assumed that at the highest overflow given by IEC60721-2-1, the total radiation will not exceed 80% of that given in Table 1. The distribution of the total daily radiation in the world and my country
IFor the distribution of total radiation, see Appendix A, Appendix NA, Appendix NB6Minimum value of atmospheric radiation at night
On a cloudless night, the atmospheric radiation is very low. The surface temperature of objects exposed at night is lower than the temperature of the surrounding atmosphere. The theoretical thermodynamic temperature T when the object reaches equilibrium with the atmospheric radiation is given by the Boltzman law: (A)
Wu Zhong:
Stefan-Boltzman constant. 5.67X10-8 W/(m*K');a
AAtmospheric radiation, in watts per square meter (W/n) (see Figure 1). In practice, the temperature will be higher due to heat conduction, convection and condensation of water vapor. On a clear night, the temperature of an exposed horizontal surface insulated from the ground can reach 11°C, while the air temperature is 0°C. The relative humidity is close to 100%.
Figure 1 shows the atmospheric radiation of night air as a function of the atmospheric temperature at 2m above the ground. On a clear night, the relative humidity is usually very high:
Appendix A
(Informative Appendix)
GB/T 4797.4—2019/1EC 60721-2-4:2002 World distribution of daily total radiation exposure
Figure A.1 Figure A.2 and Figure A.8 show relative total radiation exposure (June, December and annual average values) measured by satellite (see Note 1). Relative total radiation exposure is defined as the ratio of the total radiation exposure measured on the Earth's surface to the total radiation exposure outside the Earth (i.e. the solar radiation exposure outside the atmosphere in a plane perpendicular to the solar axis). In order to obtain the daily average total radiation exposure on the Earth's surface, the white fraction marked on the figure is multiplied by the daily average total radiation exposure outside the Earth. The value is given as a number for geographical latitude, see Table A.1. Note 1: Reference document for data source:
(.Maior et al.: World map of relative total solar radiation. World Meteorological Organization. Technical Note No. 172 Annex, WM0-No. 5570 , Geneva (1987). NOTE 2: The value of the daily irradiance in kWh/m2 is determined by averaging the monthly and annual irradiance values in MJ/m2. For example, the monthly irradiance value for June is divided by 30. For December by 31. For the annual irradiance value, it is divided by 365. Example:
This example shows how to determine the average daily total solar radiation in June at the southern tip of the California Peninsula. From the point in Figure A.1 (at about 23 degrees north latitude) around the 60% isotropic line, the percentage passing through this point is estimated to be 62%. According to Table A.1, the estimated value for the June total solar radiation at 23 degrees north latitude is 11.16 kWh/m2. Multiplying this value by the above ratio, the average daily total solar radiation is about 6.9 kh/m2. The average daily total solar radiation outside the Earth
is in "watt-hours per square meter
GB/T 4797.4—2019/IEC 60721-2-4:2002 Latitude
Table A.1 (continued)
Unit is kilowatt-hour per square meter
GB/T 4797.4—2019/IEC 60721-2-4:20029
GB/T 4797.4—2019/IEC 60721-2-4:2002 Figure
GB/T 4797.4—2019/1EC 60721-2-4:2002E2002 The energy received by a surface perpendicular to the direct solar radiation can reach 1120 W/m2. For flat land far away from industrial areas and urban areas, when the solar radiation angle exceeds 60°, 1120 W/m2 is representative to a certain extent: Note: The water vapor content in the vertical volume of the atmosphere is measured by the corresponding precipitation height cII. Similarly, the oxygen content is measured by the corresponding height of ozone at standard temperature and pressure. The scattering and absorption of aerosol particles are expressed by the β Angstrom turbidity coefficient, that is, the extinction distance of single-wavelength radiation with a wavelength of 1 m in the atmosphere.
Direct solar radiation decreases with the increase of air turbidity. In industrial and humid hot and desert areas, the particle density in the air is higher and the turbidity is relatively high. The air turbidity in urban areas is also relatively high. It is lower in mountainous areas. Table 1 gives the recommended maximum values of total radiation received by a surface perpendicular to direct solar radiation at noon without clouds. In a few hours at noon, this value only changes by a few percentage points, so it can represent the situation in a few hours in a certain period of time. Table 1 Typical peak values of total radiation
Subhumid heat and desert
Large cities
5.2 Monthly and annual averages of total solar radiation Flatland
Unit: watt per square meter
The thermal effect of solar radiation on the surface usually depends on the short-term radiation near noon. However, the photochemical reaction is related to the integral of the irradiation intensity over time, that is, the irradiation amount. For the purpose of comparison, the irradiation amount is the most commonly used data. In December, due to the long duration of light, the monthly average total irradiation near the South Pole can reach 10.8 kWh/m, and the area outside the South Pole is about 8.4 kWh/m
The maximum annual average daily total irradiation reaches 6.6 kWh/m, which mainly occurs in desert areas. 5.3 Synchronous values of maximum temperature and solar radiation The minimum value of the air turbidity coefficient is measured in cold air. Therefore, the values listed in Table 1 will not appear when the temperature reaches the highest. It can be assumed that at the highest overflow given by IEC60721-2-1, the total radiation will not exceed 80% of that given in Table 1. The distribution of the total daily radiation in the world and my country
IFor the distribution of total radiation, see Appendix A, Appendix NA, Appendix NB6Minimum value of atmospheric radiation at night
On a cloudless night, the atmospheric radiation is very low. The surface temperature of objects exposed at night is lower than the temperature of the surrounding atmosphere. The theoretical thermodynamic temperature T when the object reaches equilibrium with the atmospheric radiation is given by the Boltzman law: (A)
Wu Zhong:
Stefan-Boltzman constant. 5.67X10-8 W/(m*K');a
AAtmospheric radiation, in watts per square meter (W/n) (see Figure 1). In practice, the temperature will be higher due to heat conduction, convection and condensation of water vapor. On a clear night, the temperature of an exposed horizontal surface insulated from the ground can reach 11°C, while the air temperature is 0°C. The relative humidity is close to 100%.
Figure 1 shows the atmospheric radiation of night air as a function of the atmospheric temperature at 2m above the ground. On a clear night, the relative humidity is usually very high:
Appendix A
(Informative Appendix)
GB/T 4797.4—2019/1EC 60721-2-4:2002 World distribution of daily total radiation exposure
Figure A.1 Figure A.2 and Figure A.8 show relative total radiation exposure (June, December and annual average values) measured by satellite (see Note 1). Relative total radiation exposure is defined as the ratio of the total radiation exposure measured on the Earth's surface to the total radiation exposure outside the Earth (i.e. the solar radiation exposure outside the atmosphere in a plane perpendicular to the solar axis). In order to obtain the daily average total radiation exposure on the Earth's surface, the white fraction marked on the figure is multiplied by the daily average total radiation exposure outside the Earth. The value is given as a number for geographical latitude, see Table A.1. Note 1: Reference document for data source:
(.Maior et al.: World map of relative total solar radiation. World Meteorological Organization. Technical Note No. 172 Annex, WM0-No. 5570 , Geneva (1987). NOTE 2: The value of the daily irradiance in kWh/m2 is determined by averaging the monthly and annual irradiance values in MJ/m2. For example, the monthly irradiance value for June is divided by 30. For December by 31. For the annual irradiance value, it is divided by 365. Example:
This example shows how to determine the average daily total solar radiation in June at the southern tip of the California Peninsula. From the point in Figure A.1 (at about 23 degrees north latitude) around the 60% isotropic line, the percentage passing through this point is estimated to be 62%. According to Table A.1, the estimated value for the June total solar radiation at 23 degrees north latitude is 11.16 kWh/m2. Multiplying this value by the above ratio, the average daily total solar radiation is about 6.9 kh/m2. The average daily total solar radiation outside the Earth
is in "watt-hours per square meter
GB/T 4797.4—2019/IEC 60721-2-4:2002 Latitude
Table A.1 (continued)
Unit is kilowatt-hour per square meter
GB/T 4797.4—2019/IEC 60721-2-4:20029
GB/T 4797.4—2019/IEC 60721-2-4:2002 Figure
GB/T 4797.4—2019/1EC 60721-2-4:2002E2. Figure A.8 shows the relative total irradiance (June, December and annual average values) measured by satellite (see Note 1). Relative total irradiance is defined as the ratio of the total irradiance measured on the Earth's surface to the total irradiance outside the Earth (i.e. the solar irradiance outside the atmosphere in a plane perpendicular to the solar axis). To obtain the daily average of the total irradiance on the Earth's surface, the white fraction indicated on the figure is multiplied by the daily average of the total irradiance outside the Earth. The value is given as a number for geographical latitude, see Table A.1. Note 1: Reference document to data source:
(.Maior et al.: World map of relative total solar radiation. World Meteorological Organization. Technical Note No. 172, Annex, WM0-No. 5570, Geneva (1987). Note 2: Determination of k The irradiance value in Wh/m2 is obtained by averaging the monthly and annual irradiance values in MJ/m2. For example, the monthly irradiance value for June is divided by 30. For December, it is divided by 31. And the annual irradiance value is divided by 365. For example:
This example shows how to determine the average daily total solar radiation in June at the southern tip of the California Peninsula. From the point in Figure A.1 (at about 23 degrees north latitude) around the 60% isotropic line, the percentage value passing through this point is estimated to be 62%. According to Table A.1, the estimated value for the June total solar radiation at 23 degrees north latitude is 11.16 kWh/m. Multiplying this value by the above ratio, the average daily total solar radiation is about 6.9 kh/m. The average daily total solar radiation outside the earth
is in "watt-hours per square meter
GB/T 4797.4—2019/IEC 60721-2-4:2002 Latitude
Table A.1 (continued)
Unit is kilowatt-hour per square meter
GB/T 4797.4—2019/IEC 60721-2-4:20029
GB/T 4797.4—2019/IEC 60721-2-4:2002 Figure
GB/T 4797.4—2019/1EC 60721-2-4:2002E2. Figure A.8 shows the relative total irradiance (June, December and annual average values) measured by satellite (see Note 1). Relative total irradiance is defined as the ratio of the total irradiance measured on the Earth's surface to the total irradiance outside the Earth (i.e. the solar irradiance outside the atmosphere in a plane perpendicular to the solar axis). To obtain the daily average of the total irradiance on the Earth's surface, the white fraction indicated on the figure is multiplied by the daily average of the total irradiance outside the Earth. The value is given as a number for geographical latitude, see Table A.1. Note 1: Reference document to data source:
(.Maior et al.: World map of relative total solar radiation. World Meteorological Organization. Technical Note No. 172, Annex, WM0-No. 5570, Geneva (1987). Note 2: Determination of k The irradiance value in Wh/m2 is obtained by averaging the monthly and annual irradiance values in MJ/m2. For example, the monthly irradiance value for June is divided by 30. For December, it is divided by 31. And the annual irradiance value is divided by 365. For example:
This example shows how to determine the average daily total solar radiation in June at the southern tip of the California Peninsula. From the point in Figure A.1 (at about 23 degrees north latitude) around the 60% isotropic line, the percentage value passing through this point is estimated to be 62%. According to Table A.1, the estimated value for the June total solar radiation at 23 degrees north latitude is 11.16 kWh/m. Multiplying this value by the above ratio, the average daily total solar radiation is about 6.9 kh/m. The average daily total solar radiation outside the earth
is in "watt-hours per square meter
GB/T 4797.4—2019/IEC 60721-2-4:2002 Latitude
Table A.1 (continued)
The unit is kilowatt-hour per square meter
GB/T 4797.4—2019/IEC 60721-2-4:20029
GB/T 4797.4—2019/IEC 60721-2-4:2002Figure
GB/T 4797.4—2019/1EC 60721-2-4:2002E
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