——從“導熱油”到“導熱鹽”槽式熔鹽發電技術創新發展探索
作為最成熟的太(tai)陽(yang)能聚(ju)光發電技(ji)術之(zhi)一(yi)——線(xian)聚(ju)焦拋物面槽式光熱發電技(ji)術,目前在國內開(kai)展(zhan)沙漠戈(ge)壁風電、光伏大(da)基(ji)地進展(zhan)中,作為容量型光熱熔鹽(yan)儲(chu)能調峰電站(zhan)應(ying)用(yong)技(ji)術,需要被更多專家們和投(tou)資商(shang)們認(ren)可(ke)和信賴,需要更多創新思維和先(xian)進技(ji)術的融合應(ying)用(yong)。
一(yi)個成熟穩定的(de)(de)(de)(de)聚光(guang)集(ji)熱(re)(re)技(ji)(ji)術(shu)(shu)(shu),從(cong)最初的(de)(de)(de)(de)集(ji)熱(re)(re)開口(kou)2500mm,發(fa)(fa)展到開口(kou)5000mm,再到成熟應用最多的(de)(de)(de)(de)5770mm集(ji)熱(re)(re)器(qi),以(yi)及(ji)創(chuang)新(xin)(xin)路(lu)上(shang)的(de)(de)(de)(de)6770mm,再到更大集(ji)熱(re)(re)開口(kou)7500mm,跨越到新(xin)(xin)時(shi)代世界(jie)目(mu)前最大規模迪拜項目(mu)的(de)(de)(de)(de)開口(kou)8200mm,到中國(guo)(guo)企(qi)(qi)業自主研發(fa)(fa)創(chuang)新(xin)(xin)的(de)(de)(de)(de)更大開口(kou)8600mm集(ji)熱(re)(re)器(qi),彰(zhang)顯(xian)大國(guo)(guo)重(zhong)(zhong)器(qi)創(chuang)新(xin)(xin)精(jing)神。在國(guo)(guo)家“雙(shuang)控(kong)”任(ren)務“雙(shuang)碳(tan)”目(mu)標(biao)的(de)(de)(de)(de)多重(zhong)(zhong)政策利好(hao)下(xia),結(jie)合沙(sha)漠地(di)(di)區(qu)光(guang)熱(re)(re)、光(guang)伏(fu)、風電(dian)(dian)大基地(di)(di),需(xu)要如何(he)才能讓(rang)更廣大投(tou)資商,特別是以(yi)國(guo)(guo)家隊(dui)央企(qi)(qi)發(fa)(fa)電(dian)(dian)集(ji)團帶領的(de)(de)(de)(de)諸多發(fa)(fa)電(dian)(dian)企(qi)(qi)業成熟槽式(shi)技(ji)(ji)術(shu)(shu)(shu)的(de)(de)(de)(de)多重(zhong)(zhong)應用。透過首批示范項目(mu)諸多產業鏈上(shang)下(xia)游的(de)(de)(de)(de)企(qi)(qi)業健全,給槽式(shi)技(ji)(ji)術(shu)(shu)(shu)的(de)(de)(de)(de)創(chuang)新(xin)(xin)發(fa)(fa)展帶來了前所未有機(ji)遇。如何(he)還能夠重(zhong)(zhong)新(xin)(xin)出(chu)發(fa)(fa),腳(jiao)踏實地(di)(di),創(chuang)造(zao)嶄新(xin)(xin)的(de)(de)(de)(de)機(ji)遇,打造(zao)成熟技(ji)(ji)術(shu)(shu)(shu)的(de)(de)(de)(de)新(xin)(xin)時(shi)代應用典(dian)范,顛覆認知,需(xu)要在總結(jie)歷史的(de)(de)(de)(de)基礎上(shang),探索出(chu)可行之路(lu)。
作為太(tai)陽(yang)能光(guang)-熱-電的(de)多次(ci)轉換發(fa)電方式利用,按照(zhao)火(huo)電發(fa)展技術模式推進聚(ju)光(guang)太(tai)陽(yang)能,從中溫(wen)(wen)(wen)中壓——高(gao)溫(wen)(wen)(wen)高(gao)壓——超臨(lin)界——超超臨(lin)界的(de)更(geng)高(gao)發(fa)電機組效(xiao)(xiao)率(lv)思維,更(geng)需(xu)要站在不同(tong)視(shi)角下(xia)(xia),看問(wen)題,需(xu)要研究太(tai)陽(yang)能的(de)本質問(wen)題,也(ye)有(you)相對熟悉太(tai)陽(yang)能的(de)專家觀點,太(tai)陽(yang)能一(yi)定是在合適的(de)溫(wen)(wen)(wen)度(du)下(xia)(xia)優先利用,針(zhen)對真空(kong)管(guan)熱水(shui)器一(yi)定是在低溫(wen)(wen)(wen)區(qu)的(de)范圍(wei)內效(xiao)(xiao)率(lv)更(geng)高(gao),聚(ju)光(guang)倍數的(de)不同(tong),使用溫(wen)(wen)(wen)度(du)范圍(wei)不同(tong),最終會有(you)他適合的(de)溫(wen)(wen)(wen)度(du)區(qu)間,或(huo)者叫更(geng)高(gao)效(xiao)(xiao)率(lv)下(xia)(xia)的(de)溫(wen)(wen)(wen)區(qu)利用才是發(fa)揮(hui)最大的(de)價值。
圖1槽式光(guang)熱(re)電站(zhan)儲(chu)發電島(圖片來源(yuan)于網路)
目前(qian)一般火電(dian)(dian)機組(zu)的(de)(de)(de)發(fa)(fa)電(dian)(dian)小(xiao)時數(shu)(shu)是7500多(duo)(duo)小(xiao)時的(de)(de)(de)利(li)用(yong)(yong)設(she)計,和光熱電(dian)(dian)站(zhan)2000小(xiao)時(按照國(guo)內環境下不(bu)考慮增加(jia)太(tai)陽能(neng)倍(bei)數(shu)(shu)評(ping)估(gu),目前(qian)來(lai)看(kan)大基(ji)地項(xiang)目后面增加(jia)太(tai)陽倍(bei)數(shu)(shu)越大項(xiang)目經(jing)(jing)濟(ji)性有(you)可能(neng)越差,除非(fei)國(guo)家(jia)再給更(geng)高(gao)(gao)(gao)儲能(neng)電(dian)(dian)價(jia)補貼,或者參與電(dian)(dian)力現貨交易晚(wan)高(gao)(gao)(gao)峰的(de)(de)(de)高(gao)(gao)(gao)價(jia)發(fa)(fa)電(dian)(dian)小(xiao)時數(shu)(shu)再延長,目前(qian)看(kan)基(ji)本上(shang)不(bu)太(tai)可能(neng)的(de)(de)(de)樣子,一般晚(wan)高(gao)(gao)(gao)峰3-4小(xiao)時就很好了(le),如(ru)果大基(ji)地的(de)(de)(de)區域看(kan)起來(lai)更(geng)低(di)而不(bu)是更(geng)高(gao)(gao)(gao))左右的(de)(de)(de)利(li)用(yong)(yong)設(she)計,來(lai)追求汽(qi)輪發(fa)(fa)電(dian)(dian)機組(zu)一樣的(de)(de)(de)更(geng)高(gao)(gao)(gao)效率(lv)提升(sheng)思維(wei),顯(xian)然需要(yao)數(shu)(shu)學(xue)經(jing)(jing)濟(ji)專家(jia)們來(lai)分析評(ping)估(gu)經(jing)(jing)濟(ji)性的(de)(de)(de)取舍和高(gao)(gao)(gao)低(di)。槽式技術需要(yao)在自己適合的(de)(de)(de)溫(wen)(wen)(wen)度區間發(fa)(fa)揮自身的(de)(de)(de)優(you)勢,從(cong)中溫(wen)(wen)(wen)中壓的(de)(de)(de)全系統裝備成本更(geng)低(di)考慮,從(cong)更(geng)低(di)溫(wen)(wen)(wen)度利(li)用(yong)(yong)、系統模(mo)塊靈(ling)活性,從(cong)更(geng)高(gao)(gao)(gao)利(li)用(yong)(yong)小(xiao)時數(shu)(shu)上(shang)面下更(geng)多(duo)(duo)功夫,而不(bu)是一味(wei)追求汽(qi)輪機的(de)(de)(de)發(fa)(fa)電(dian)(dian)效率(lv),放棄(qi)自身的(de)(de)(de)綜合優(you)勢。
欲與儲能(neng)(neng)(neng)融一(yi)(yi)(yi)體(ti),集傳(chuan)(chuan)儲熱(re)(re)于一(yi)(yi)(yi)身。創新利(li)用熔(rong)鹽(yan)(yan)(yan)(yan)儲熱(re)(re)的本質,挖掘熔(rong)鹽(yan)(yan)(yan)(yan)集熱(re)(re)、導熱(re)(re)、傳(chuan)(chuan)熱(re)(re)、儲熱(re)(re)一(yi)(yi)(yi)體(ti)化,并追求熔(rong)鹽(yan)(yan)(yan)(yan)溫(wen)(wen)差的更大(da)溫(wen)(wen)區利(li)用,采(cai)用更低(di)(di)熔(rong)鹽(yan)(yan)(yan)(yan)新材料(liao)徹底解決系統的多次換熱(re)(re)難(nan)題(ti)。技術(shu)創新支(zhi)撐(cheng)行業和產業的快(kuai)速發展(zhan),放(fang)棄目(mu)(mu)(mu)前(qian)(qian)二元(yuan)熔(rong)鹽(yan)(yan)(yan)(yan)產品(pin)的較高(gao)熔(rong)點難(nan)題(ti),加(jia)(jia)速降(jiang)低(di)(di)熔(rong)鹽(yan)(yan)(yan)(yan)的低(di)(di)熔(rong)點溫(wen)(wen)度,從220℃降(jiang)低(di)(di)到(dao)140℃以下,增加(jia)(jia)80℃的溫(wen)(wen)差就(jiu)接近了(le)槽式(shi)技術(shu)目(mu)(mu)(mu)前(qian)(qian)熔(rong)鹽(yan)(yan)(yan)(yan)儲熱(re)(re)溫(wen)(wen)差的90℃,再加(jia)(jia)上啟動(dong)防凝加(jia)(jia)熱(re)(re)的溫(wen)(wen)度空間(jian),就(jiu)讓溫(wen)(wen)差加(jia)(jia)上了(le)至少一(yi)(yi)(yi)倍(bei),存取同樣的熱(re)(re)量,成本降(jiang)低(di)(di)顯(xian)著。更利(li)于熔(rong)鹽(yan)(yan)(yan)(yan)集熱(re)(re)導熱(re)(re)傳(chuan)(chuan)熱(re)(re)的匹配,減少高(gao)溫(wen)(wen)鹽(yan)(yan)(yan)(yan)導熱(re)(re)對(dui)于全集熱(re)(re)系統的裝(zhuang)備整體(ti)性能(neng)(neng)(neng)提(ti)高(gao)帶來(lai)的大(da)幅(fu)成本增加(jia)(jia)難(nan)題(ti),放(fang)棄二元(yuan)鹽(yan)(yan)(yan)(yan)的集熱(re)(re)導熱(re)(re)傳(chuan)(chuan)熱(re)(re),更是線聚焦槽式(shi)技術(shu)目(mu)(mu)(mu)前(qian)(qian)唯一(yi)(yi)(yi)可(ke)再次發展(zhan)的基石(shi),也是讓更多光熱(re)(re)發電小(xiao)時數大(da)幅(fu)提(ti)升(sheng),更高(gao)效(xiao)率利(li)用太陽能(neng)(neng)(neng)技術(shu)的最佳方式(shi)。
圖(tu)2槽式熔鹽發(fa)電示意圖(tu)(圖(tu)片來(lai)自于網絡)
目前(qian)槽(cao)(cao)式熔(rong)(rong)鹽儲(chu)(chu)(chu)熱(re)(re)的(de)(de)溫(wen)(wen)差利(li)(li)用(yong)(yong)(yong)(yong)(yong)不足100℃是制約(yue)槽(cao)(cao)式熔(rong)(rong)鹽材料(liao)利(li)(li)用(yong)(yong)(yong)(yong)(yong)更大量的(de)(de)困境,通過低(di)熔(rong)(rong)點、低(di)成本、低(di)氯離子熔(rong)(rong)鹽新(xin)型儲(chu)(chu)(chu)能(neng)材料(liao)的(de)(de)綜(zong)合利(li)(li)用(yong)(yong)(yong)(yong)(yong),增(zeng)大溫(wen)(wen)差220℃以(yi)上減少(shao)熔(rong)(rong)鹽使(shi)用(yong)(yong)(yong)(yong)(yong)量。槽(cao)(cao)式熔(rong)(rong)鹽電(dian)站系統設(she)(she)計中(zhong)減少(shao)導熱(re)(re)油板塊,多(duo)次換(huan)熱(re)(re)系統改為(wei)一次鹽水換(huan)熱(re)(re)系統,采(cai)用(yong)(yong)(yong)(yong)(yong)高溫(wen)(wen)罐、低(di)溫(wen)(wen)罐、增(zeng)設(she)(she)恒溫(wen)(wen)罐的(de)(de)方式來平衡集(ji)熱(re)(re)場(chang)與儲(chu)(chu)(chu)熱(re)(re)島、常規島之前(qian)的(de)(de)匹配(pei)設(she)(she)計利(li)(li)用(yong)(yong)(yong)(yong)(yong),實現(xian)槽(cao)(cao)式光熱(re)(re)發(fa)電(dian)技(ji)術(shu)本質的(de)(de)飛躍。加(jia)(jia)上在能(neng)源大基地項目中(zhong),增(zeng)加(jia)(jia)利(li)(li)用(yong)(yong)(yong)(yong)(yong)棄風(feng)棄光電(dian)加(jia)(jia)熱(re)(re)熔(rong)(rong)鹽儲(chu)(chu)(chu)能(neng)技(ji)術(shu)的(de)(de)融合利(li)(li)用(yong)(yong)(yong)(yong)(yong),打通集(ji)光熱(re)(re)、光伏、風(feng)電(dian)為(wei)一體化綜(zong)合熔(rong)(rong)鹽儲(chu)(chu)(chu)能(neng)發(fa)電(dian)技(ji)術(shu)的(de)(de)降本增(zeng)效,多(duo)能(neng)互補綜(zong)合利(li)(li)用(yong)(yong)(yong)(yong)(yong)優(you)勢,為(wei)成熟槽(cao)(cao)式技(ji)術(shu)的(de)(de)生存發(fa)展創造更多(duo)空間。
成(cheng)熟的(de)槽(cao)式熔(rong)鹽儲能(neng)發(fa)(fa)電(dian)技(ji)(ji)術(shu)充分發(fa)(fa)揮自身(shen)技(ji)(ji)術(shu)特點,在(zai)加快構(gou)建(jian)清潔低碳、安(an)全高(gao)(gao)效的(de)能(neng)源體系(xi)中,充分發(fa)(fa)揮光熱(re)熔(rong)鹽儲能(neng)技(ji)(ji)術(shu)在(zai)構(gou)建(jian)新(xin)型電(dian)力系(xi)統中的(de)平臺和(he)樞紐(niu)作用,支持沙漠戈壁地區能(neng)源大基(ji)地項(xiang)目發(fa)(fa)揮積極(ji)接入和(he)消(xiao)納(na)新(xin)能(neng)源。爭取調(diao)峰(feng)調(diao)頻電(dian)源補償機制,深入挖(wa)掘需求(qiu)響(xiang)應潛力,提高(gao)(gao)負荷側對新(xin)能(neng)源的(de)調(diao)節(jie)能(neng)力。
注:本文由王工(13810518839)供稿,歡迎行業朋友聯系交流。