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一、前言
作為建築內部重點耗能設備,中央空調係統的耗電一般要占整座建築電耗的 40% yishang。erzhongyangkongtiaojizushiyimanzushiyongchangsuodezuidalengrelianglaijinxingshejide,erzaishijiyingyongzhongjuedaduoshuyonghuzaishiyongshi,lengrefuheshibianhuade,yibanyuzuidashejigonglengreliangcunzaizhehendadechayi,xitonggebufen 90% 以上運行在非滿載額定狀態。傳統的中央空調水、風feng係xi統tong均jun采cai用yong調tiao節jie閥fa門men或huo風feng門men開kai度du的de方fang式shi來lai調tiao節jie水shui量liang和he風feng量liang,這zhe種zhong調tiao節jie方fang式shi的de缺que點dian不bu僅jin是shi消xiao耗hao大da量liang能neng量liang,而er且qie調tiao節jie品pin質zhi難nan以yi達da到dao理li想xiang狀zhuang態tai而er導dao致zhi空kong調tiao的de舒shu適shi度du不bu良liang。
利用變頻器通過對中央空調的末端空調風機箱、冷凍水 / 冷卻水水泵、冷卻塔風機、甚至主機驅動電機轉速等進行控製調節,從而使空調各子係統風量、水流量等負荷工況參數按負荷情況得到適時調節,不但能改善係統的調節品質,達到閥門、風門節 / 回流調節、變極調速等落後調節方式所不能相比的調節性能,改善空調的舒適性;還能節省大量電能。
二、中央空調係統的構成及工作原理
製(zhi)冷(leng)機(ji)通(tong)過(guo)壓(ya)縮(suo)機(ji)將(jiang)製(zhi)冷(leng)劑(ji)壓(ya)縮(suo)成(cheng)液(ye)態(tai)後(hou)送(song)蒸(zheng)發(fa)器(qi)中(zhong)與(yu)冷(leng)凍(dong)水(shui)進(jin)行(xing)熱(re)交(jiao)換(huan),將(jiang)冷(leng)凍(dong)水(shui)製(zhi)冷(leng),冷(leng)凍(dong)水(shui)泵(beng)將(jiang)冷(leng)凍(dong)水(shui)送(song)到(dao)各(ge)風(feng)機(ji)風(feng)口(kou)的(de)冷(leng)卻(que)盤(pan)管(guan)中(zhong),由(you)風(feng)機(ji)吹(chui)送(song)冷(leng)風(feng)達(da)到(dao)降(jiang)溫(wen)的(de)目(mu)的(de)。經(jing)蒸(zheng)發(fa)後(hou)的(de)製(zhi)冷(leng)劑(ji)在(zai)冷(leng)凝(ning)器(qi)中(zhong)釋(shi)放(fang)出(chu)熱(re)量(liang),與(yu)冷(leng)卻(que)循(xun)環(huan)水(shui)進(jin)行(xing)熱(re)交(jiao)換(huan),由(you)冷(leng)卻(que)水(shui)泵(beng)將(jiang)帶(dai)有(you)熱(re)量(liang)的(de)冷(leng)卻(que)水(shui)送(song)到(dao)散(san)熱(re)水(shui)塔(ta)上(shang)由(you)水(shui)塔(ta)風(feng)扇(shan)對(dui)其(qi)進(jin)行(xing)噴(pen)淋(lin)冷(leng)卻(que),與(yu)大(da)氣(qi)之(zhi)間(jian)進(jin)行(xing)熱(re)交(jiao)換(huan),將(jiang)熱(re)量(liang)散(san)發(fa)到(dao)大(da)氣(qi)中(zhong)去(qu),如(ru)下(xia)圖(tu)所(suo)示(shi): 
冷凍水循環係統:由(you)冷(leng)凍(dong)泵(beng)及(ji)冷(leng)凍(dong)水(shui)管(guan)道(dao)組(zu)成(cheng)。從(cong)冷(leng)凍(dong)主(zhu)機(ji)流(liu)出(chu)的(de)冷(leng)凍(dong)水(shui)由(you)冷(leng)凍(dong)泵(beng)加(jia)壓(ya)送(song)入(ru)冷(leng)凍(dong)水(shui)管(guan)道(dao),通(tong)過(guo)各(ge)房(fang)間(jian)的(de)盤(pan)管(guan),帶(dai)走(zou)房(fang)間(jian)內(nei)的(de)熱(re)量(liang),使(shi)房(fang)間(jian)內(nei)的(de)溫(wen)度(du)下(xia)降(jiang)。同(tong)時(shi),房(fang)間(jian)內(nei)的(de)熱(re)量(liang)被(bei)冷(leng)凍(dong)水(shui)吸(xi)收(shou),使(shi)冷(leng)凍(dong)水(shui)的(de)溫(wen)度(du)升(sheng)高(gao)。溫(wen)度(du)升(sheng)高(gao)了(le)的(de)循(xun)環(huan)水(shui)經(jing)冷(leng)凍(dong)主(zhu)機(ji)後(hou)又(you)成(cheng)為(wei)冷(leng)凍(dong)水(shui),如(ru)此(ci)循(xun)環(huan)不(bu)已(yi)。從(cong)冷(leng)凍(dong)主(zhu)機(ji)流(liu)出(chu),進(jin)入(ru)房(fang)間(jian)的(de)冷(leng)凍(dong)水(shui)簡(jian)稱(cheng)為(wei)“出水”,流經所有房間後回到冷凍主機的冷凍水簡稱為“回水”。無疑回水的溫度將高於出水的溫度形成溫差。
冷卻水循環係統 :由冷卻泵、冷卻水管道及冷卻塔組成。冷凍主機在進行熱交換、shishuiwenlengquedetongshi,bijiangshifangdaliangdereliang。gaireliangbeilengqueshuixishou,shilengqueshuiwendushenggao。lengquebengjiangshenglewendelengqueshuiyarulengqueta,shizhizailengquetazhongyudaqijinxingrejiaohuan,ranhouzaijiangjiangwenledelengqueshui,songhuidaolengdongjizu。rucibuduanxunhuan,daizoulelengdongzhujishifangdereliang。liujinlengdongzhujidelengqueshuijianchengwei“進水”,從冷凍主機流回冷卻塔的冷卻水簡稱為“回水”。同樣,回水的溫度將高於進水的溫度形成溫差。
三、中央空調變頻器節能改造
由於設計時,中央空調係統必須按天氣最熱、負荷最大時設計,並且留10-20%shejiyuliang,ranershijishangjuedabufenshijiankongtiaoshibuhuiyunxingzaimanfuhezhuangtaixia,cunzaijiaodadefuyu,suoyijienengdeqianlijiujiaoda,qizhong,lengdongzhujikeyigenjufuzaibianhuasuizhijiazaihuojianzai,lengdongshuibenghelengqueshuibengquebunengsuifuzaibianhuazuochuxiangyingtiaojie,cunzaihendadelangfei。 水泵係統的流量與壓差以前是靠閥門和旁通調節來完成,因此,不可避免地存在較大截流損失和大流量、高壓力、diwenchadexianxiang,bujindalianglangfeidianneng,erqiehaizaochengzhongyangkongtiaozuimoduandabudaohelixiaoguodeqingkuang。weijiejuezhexiewentixushishuibengsuizhefuzaidebianhuatiaojieshuiliuliangbingguanbipangtong。zaiyinshuibengcaiyongdeshiY―△起動方式,電機的起動電流平均為其額定電流的3~4倍,在如此大的電流衝擊下,接觸器、電機的使用壽命大大下降,同時,起動時的機械衝擊和停泵時的水錘現象,容易對機械零件、軸承、閥門、管道等造成破壞,從而增加維修工作量和備品、備件費用。
1.冷凍係統的改造
lengdongxitongjinxinghengwenkongzhi。yihuishuiwenduxinhaozuoweimubiaoxinhao,shiyachademubiaozhikeyizaiyidingfanweineigenjuhuishuiwendujinxingshidangtiaozheng。jiushishuo,dangfangjianwendujiaodishi,shiyachademubiaozhishidangxiajiangyixie,jianxiaolengdongbengdepingjunzhuansu,tigaojienengxiaoguo。zheyangyilai,jikaolvdaolehuanjingwendudeyinsu,yougaishanlejienengxiaoguo。jutifangfashi:zaibaozhenglengdongjizulengdongshuiliuliangsuoxuqiantixia,quedingyigelengdongbengbianpinqigongzuodezuixiaogongzuopinlv,kejiangqishedingweixiaxianpinlv。shuibengdianjipinlvtiaojieshitongguoanzhuangzaixitongguandaoshangwenduchuanganqicehuishuiwendu。wenkongqijiangqiyushedingzhijinxingbijiao。danglengdonghuishuiwendudayushedingzhishi,bianpinqishuchushangxianpinlv,shuibengdianjigaosuyunzhuan;當冷凍回水溫度小於設定溫度時電機以設定的頻率工作。
2.冷卻係統的改造
冷卻係統變頻改造采用兩個溫度傳感器檢測冷卻水的進水溫度和回水溫度, 當進水和回水溫差大時, 冷卻水泵及冷卻風機加速運行, 使進水和回水溫差保持在5℃左右; 當進水和回水溫差偏小時, 降低冷卻水泵和冷卻風機的速度, 以達到節能的目的。
四、 結束語 中央空調是現代物業大廈,賓館商場不可缺少的設施,它能給人們帶來四季如春,溫馨舒適的每一天,用交流變頻調速器對中央空調係統的風機、水泵進行調速改造,不但操作方便、容易、維wei護hu量liang小xiao,而er且qie有you顯xian著zhu的de節jie電dian效xiao果guo,采cai用yong溫wen度du濕shi度du傳chuan感gan器qi,再zai配pei上shang調tiao節jie器qi,與yu變bian頻pin器qi構gou成cheng閉bi環huan控kong製zhi係xi統tong,就jiu可ke以yi排pai除chu人ren工gong調tiao節jie因yin素su的de不bu足zu,實shi現xian高gao度du自zi動dong化hua調tiao節jie,提ti高gao空kong調tiao的de質zhi量liang和he效xiao果guo。
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