[工學(xué)]建筑環(huán)境學(xué)chapter41-2thermalcomfortable-wenkub
2023-03-09 00:50:03 本頁面
【正文】 es 電極 + ionized gas電離氣體 +electric current 電流 ?Typically, such lamps use a noble gas (argon, neon, krypton and xenon) or a mixture of these gases. 惰性氣體（氬、氖、氪 、 氙 ） ?resulting in visible light or ultraviolet radiation ?Ultraviolet radiation is converted to visible light by a fluorescent coating how to evaluate the Properties of lamps 如何評價燈的性能？ 1) Luminous efficacy 光效 i n p u tp o w er E l ec t r i ca lo u t p u tf l u x L u m i n o u sef f i ca cy l u m i n o u s ? Unit: lumens /watt (lm/W) 2) Life 壽命 ? The luminous efficacy of a lamp decreases with time 燈的光效隨著使用時間降低 ? for a discharge lamp it may fall by as much as 50% before the lamp fails. 對氣體放電燈，在失效前光效會下降 50% ? The nominal life of a lamp is usually determined by the manufacturer by considering the failure rate of a particular model of lamp bined with its fall in light output. 燈的壽命一般由廠家考慮某批燈的失效率結(jié)合光效降低程度而定 ? In a large installation it is desirable that all the lamps are replaced at the same time on a specified maintenance schedule. 在安裝大量燈的情況下，在維護(hù)計劃中，燈要求同時更換掉。t flow from the image, the image is virtual. Rays seem to e from behind the mirror, but, of course, they don39。當(dāng)光強(qiáng)體被通過 z軸的平面截割時，在平面上獲得一封閉的交線。 燈具效率 ? 任何材料制成的燈罩，對于投射在其表面的光通量都要被它吸收一部分，光源本身也要吸收少量的反射光，余下的才是燈具向周圍空間投射的光通量 ? 在規(guī)定條件下測得的燈具發(fā)射光通量與燈具內(nèi)的全部光源在燈具外按規(guī)定條件測得的光通量之比 how to do Lighting design 照明設(shè)計 First , find the standard service illuminance levels 照度標(biāo)準(zhǔn) Table . P156 for different applications The aim of Lighting design is to reach the illuminance levels Then , choose the luminaires 選擇燈具 use Lumen method 流明法 to calculate the number of lamps needed. L L FUFFAEN???? DLOR )WL(HWLRIm ????房間指數(shù) Hm——mounted height of the luminaire above the working plane L L FUFFAEN????UF= utilisation factor 燈具的利用系數(shù) is the ratio of the total flux reaching the working plane pared to the total flux output of the lamps 光源實際投射到工作面上的有效光通量與全部燈的額定光通量之比 table P158 LLF=light loss factor 光損失系數(shù) is the ratio of the illuminance provided at some given time pared to the initial illuminance At the end of design, we should place these lamps in a regular grid pattern and their spacing must not exceed certain distances. type of luminaire + height at which they set. Typical values are as follows For fluorescent tubes in diffusing luminiaires Smax= For filament lamps in direct luminaires Smax= Figure spacing of luminaires P160 Worked example A factory space measuring 40m by 12m by 4m in height requires a service illuminance of 500lux on the work benches which are set 1m above the floor. The 65W tubular fluorescent lamps chosen have a luminous efficacy of 80lm/W. they are to be mounted on the ceiling in luminaires which have a DLOR of 50%. The room reflectances are for the ceiling and for the wall。 ? 配光曲線上的每一點，表示燈具在該方向上的發(fā)光強(qiáng)度。 behind the mirror. do di For a plane mirror: do = di and ho = hi ho hi do = distance from object to mirror di = distance from image to mirror ho = height of object hi = height of image Image is behind
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