作為太陽能光熱發電的核心技術,高溫熔融鹽儲能以它獨特的性能優勢,成為光熱發電儲能的首選。熔融鹽簡稱為熔鹽,是鹽的熔融態液體,通常說的熔鹽是指無機鹽的熔融狀態。熔鹽傳熱、蓄熱系統一般以硝酸鹽為介質,系統冷鹽部分一般為200-300℃,熱鹽部分一般為500-600℃。冷鹽通過熔鹽泵從冷鹽儲罐被送至鏡場集熱區。熔鹽吸熱后溫度升高到500℃以上,再通過管道送至熱鹽罐。熱鹽罐的熔鹽再被輸送至蒸汽發生器,產生高溫過熱蒸汽,推動汽輪機發電。
基(ji)于(yu)電(dian)(dian)伴熱系統在光熱電(dian)(dian)站(zhan)中的重要作用,目前,鎧(kai)裝礦物絕緣加熱電(dian)(dian)纜(lan)(又(you)稱鎧(kai)裝電(dian)(dian)伴熱帶)是(shi)光熱電(dian)(dian)站(zhan)電(dian)(dian)伴熱系統的首選發熱元件。
冷(leng)鹽(yan)(yan)(yan)管(guan)道(dao)一般要(yao)求維(wei)持溫(wen)度300℃左右(you),設(she)(she)計溫(wen)度不超過(guo)400℃。要(yao)求電(dian)(dian)伴熱系統能夠(gou)在電(dian)(dian)站初(chu)次(ci)啟動或停機再啟時(shi)提前(qian)為管(guan)道(dao)預熱、通入熔鹽(yan)(yan)(yan)后能夠(gou)維(wei)持冷(leng)鹽(yan)(yan)(yan)管(guan)道(dao)的正常工(gong)(gong)藝溫(wen)度(-般為300℃),選(xuan)擇鎧(kai)裝礦物(wu)絕(jue)緣加(jia)熱電(dian)(dian)纜(lan)時(shi)外保護管(guan)可選(xuan)用316L或Incoloy825合(he)金無縫管(guan)。適(shi)的加(jia)熱電(dian)(dian)纜(lan),施(shi)工(gong)(gong)時(shi)注意鋪設(she)(she)均勻、緊貼管(guan)道(dao)即可。冷(leng)鹽(yan)(yan)(yan)管(guan)道(dao)溫(wen)度相對(dui)較低,且加(jia)熱電(dian)(dian)纜(lan)不與熔鹽(yan)(yan)(yan)直接(jie)接(jie)觸(chu),選(xuan)擇合(he)適(shi)的加(jia)熱電(dian)(dian)纜(lan),施(shi)工(gong)(gong)時(shi)注意鋪設(she)(she)均勻、緊貼管(guan)道(dao)即可。