Incident Angle Of Sun On Steel Fire Door

The incident angle of light is 0 ° ~ 45. The total solar radiation heat gain of different types of glass accounts for the percentage of incident radiation heat [%) the heat transfer part of glass type shooting part is transparent glass drop light color heat absorbing glass gray glass coated with nitrile paint glass section IV heat gain of external windows. The heat gain of windows of air-conditioned houses in summer includes indoor and outdoor temperature difference heat gain and solar radiation heat gain. The solar radiation heat gain is the main part of the total heat gain.

Because the heat of the window is very small and the thermal index is very low, it is considered that there is no attenuation and delay to the outdoor temperature wave through the steel fire door, and the indoor and outdoor temperature difference heat transfer and solar radiation heat gain through the window can be immediately transmitted into the room. The indoor and outdoor temperature difference heat gain of windows. The glass used for building windows can be divided into several types according to its light transmission, absorption and reflection performance. Colored and other colored glass have strong absorption capacity for infrared rays; Heat reflecting glass has strong reflection ability to infrared ray; Gray and other colored glass can absorb a large amount of visible light in the solar spectrum and can be used to prevent glare. The ingredients of endothermic glass contain high iron oxide content, so it has high absorption to the infrared part of the solar spectrum and allows a large amount of visible light to pass through. Due to the large amount of infrared absorption, the temperature of heat absorbing glass is often higher than the outdoor temperature.

The heat reflecting glass is plated with metal film or pasted with metal film (plated on the migration plastic film or sandwiched in the transparent material film) on the glass surface, which has high reflection ability for solar radiation heat. The reflectivity of glass to solar radiant heat varies with the incident angle of light (the included angle between light and the normal of glass surface). When the light is perpendicular to the glass surface (the incident angle is 0 °), the reflectivity is the smallest; As the light gradually tilts, the reflectivity increases. The reflectivity increases slowly when the incident angle increases from 0 ° to 60 °; When the incident angle increases further, the reflectivity increases rapidly. The heat gain of windows in air-conditioned houses in summer includes the heat gain of indoor and outdoor temperature difference and solar radiation. The solar radiation heat gain is the main part of the total heat gain. Because the heat of steel fireproof door is very small and the thermal index is very low, it is considered that there is no attenuation and delay of outdoor temperature wave through the window, and the indoor and outdoor temperature difference heat transfer and solar radiation heat gain through the window can be immediately transmitted into the room. When calculating the instantaneous solar radiation heat gain of the window, it is necessary to know the incident angle 9 of the sun on the steel fire door, and the incident angle is related to the solar height angle β It is related to azimuth A and other angles. In addition, these angles should also be known when calculating the window shading, which are described as follows Various angles between the sun and the earth. Figure 7-3 shows the position of the earth during its rotation around the sun. The axis of the earth's rotation (i.e. the South Arctic link) and the plane of its orbit around the sun (i.e. revolution) always maintain a fixed jaw angle of 66.5 °, and the rotation axis always points in roughly the same direction (near Polaris). Figure 7-4 shows the geometry of the sun at noon during the period from summer solstice to winter solstice. Point 0 represents the earth's center, QQ 'represents the equator, and NS line represents the earth's axis. The latitude at any point P on the ground refers to the number of angles < poq. Because the thermal insulation function of windows is different in air-conditioned buildings and natural ventilation buildings, different thermal insulation performance indexes can be put forward for them. The thermal insulation function of windows in air-conditioned buildings is to reduce the heat gain from solar radiation and indoor and outdoor temperature difference of windows.