太陽能熱水工程控制系統——水位水溫傳感器(qi)(三)

　　太陽能熱水工程控制系統——水位水溫傳感器(二)

　　連接前面部(bu)分

　　四、定溫控制、防凍控制和溫差控制

　　太陽能熱水器工程(cheng)的(de)(de)(de)(de)(de)集熱(re)(re)器(qi)(qi)比較(jiao)多，管道也比較(jiao)長，像(xiang)家用的(de)(de)(de)(de)(de)那(nei)樣(yang)自然循(xun)環無法達到集熱(re)(re)的(de)(de)(de)(de)(de)目的(de)(de)(de)(de)(de)，往往要靠水(shui)(shui)泵(beng)的(de)(de)(de)(de)(de)推動(dong)(dong)，將水(shui)(shui)箱(xiang)低(di)溫的(de)(de)(de)(de)(de)水(shui)(shui)泵(beng)進集熱(re)(re)器(qi)(qi)，將集熱(re)(re)器(qi)(qi)的(de)(de)(de)(de)(de)熱(re)(re)水(shui)(shui)推入儲熱(re)(re)水(shui)(shui)箱(xiang)，形成一個集熱(re)(re)循(xun)環的(de)(de)(de)(de)(de)狀態。我們稱這種水(shui)(shui)泵(beng)為集熱(re)(re)循(xun)環水(shui)(shui)泵(beng)。水(shui)(shui)泵(beng)的(de)(de)(de)(de)(de)動(dong)(dong)作是(shi)間歇性(xing)的(de)(de)(de)(de)(de)，只有(you)在(zai)一定(ding)的(de)(de)(de)(de)(de)溫度下，才能啟動(dong)(dong)水(shui)(shui)泵(beng)循(xun)環，控制水(shui)(shui)泵(beng)循(xun)環的(de)(de)(de)(de)(de)方式有(you)兩種：定(ding)溫控制和差溫控制。

　　1.定溫控制

　　定(ding)(ding)溫(wen)(wen)(wen)(wen)控(kong)(kong)(kong)(kong)(kong)制(zhi)的(de)(de)方(fang)法就是在(zai)太(tai)陽能集(ji)(ji)(ji)熱(re)(re)(re)(re)器(qi)(qi)(qi)的(de)(de)溫(wen)(wen)(wen)(wen)度(du)(du)(du)(du)點上(shang)，一(yi)(yi)般在(zai)靠(kao)近(jin)儲熱(re)(re)(re)(re)水箱的(de)(de)集(ji)(ji)(ji)熱(re)(re)(re)(re)器(qi)(qi)(qi)最(zui)(zui)高(gao)點上(shang)(參考水的(de)(de)分層原理)，安裝溫(wen)(wen)(wen)(wen)度(du)(du)(du)(du)探(tan)測頭(tou)，設定(ding)(ding)一(yi)(yi)個溫(wen)(wen)(wen)(wen)度(du)(du)(du)(du)，比(bi)如(ru)(ru)50℃，當太(tai)陽能集(ji)(ji)(ji)熱(re)(re)(re)(re)器(qi)(qi)(qi)中的(de)(de)水溫(wen)(wen)(wen)(wen)達到(dao)設定(ding)(ding)溫(wen)(wen)(wen)(wen)度(du)(du)(du)(du)時(shi)，比(bi)如(ru)(ru)50℃，控(kong)(kong)(kong)(kong)(kong)制(zhi)器(qi)(qi)(qi)通知循環水泵(beng)將集(ji)(ji)(ji)熱(re)(re)(re)(re)器(qi)(qi)(qi)中的(de)(de)熱(re)(re)(re)(re)水泵(beng)入(ru)儲熱(re)(re)(re)(re)水箱中，直到(dao)溫(wen)(wen)(wen)(wen)度(du)(du)(du)(du)探(tan)頭(tou)的(de)(de)溫(wen)(wen)(wen)(wen)度(du)(du)(du)(du)低(di)于溫(wen)(wen)(wen)(wen)控(kong)(kong)(kong)(kong)(kong)器(qi)(qi)(qi)的(de)(de)停(ting)止(zhi)溫(wen)(wen)(wen)(wen)度(du)(du)(du)(du)時(shi)，水泵(beng)停(ting)止(zhi)工作。溫(wen)(wen)(wen)(wen)控(kong)(kong)(kong)(kong)(kong)器(qi)(qi)(qi)的(de)(de)停(ting)止(zhi)溫(wen)(wen)(wen)(wen)度(du)(du)(du)(du)一(yi)(yi)般采用(yong)回差控(kong)(kong)(kong)(kong)(kong)制(zhi)辦(ban)法，一(yi)(yi)般比(bi)設定(ding)(ding)溫(wen)(wen)(wen)(wen)度(du)(du)(du)(du)低(di)3℃左右，這樣才不會使得水泵(beng)頻繁(fan)停(ting)啟動，造成水泵(beng)燒(shao)毀等事故。根據控(kong)(kong)(kong)(kong)(kong)制(zhi)器(qi)(qi)(qi)的(de)(de)不同，回差也不一(yi)(yi)樣，一(yi)(yi)般在(zai)2～5℃的(de)(de)較多(duo)，還有的(de)(de)控(kong)(kong)(kong)(kong)(kong)制(zhi)器(qi)(qi)(qi)還能調節(jie)回差值。定(ding)(ding)溫(wen)(wen)(wen)(wen)控(kong)(kong)(kong)(kong)(kong)制(zhi)最(zui)(zui)簡單、最(zui)(zui)可靠(kao)的(de)(de)辦(ban)法就是采用(yong)機械式溫(wen)(wen)(wen)(wen)度(du)(du)(du)(du)控(kong)(kong)(kong)(kong)(kong)制(zhi)開(kai)關，如(ru)(ru)圖(tu)5-13，將溫(wen)(wen)(wen)(wen)控(kong)(kong)(kong)(kong)(kong)輸出點接在(zai)常閉(bi)開(kai)關線路上(shang)，就可以可靠(kao)地(di)控(kong)(kong)(kong)(kong)(kong)制(zhi)集(ji)(ji)(ji)熱(re)(re)(re)(re)器(qi)(qi)(qi)的(de)(de)循環了，具體(ti)實(shi)施如(ru)(ru)圖(tu)5—14所示(shi)。

　　目前在(zai)太陽能工程(cheng)中，定溫循環已(yi)經很(hen)少(shao)(shao)用了，但個別(bie)的(de)情況(kuang)下還是有它自己的(de)優點的(de)，比(bi)(bi)如在(zai)溫度比(bi)(bi)較低的(de)地方，采用定溫循環可(ke)以減少(shao)(shao)管(guan)道的(de)熱損失。

　　當然(ran)，數字式溫(wen)控(kong)(kong)(kong)器(qi)(qi)、太陽能(neng)(neng)控(kong)(kong)(kong)制(zhi)(zhi)儀也能(neng)(neng)進行(xing)定溫(wen)循環控(kong)(kong)(kong)制(zhi)(zhi)，但(dan)必(bi)須注意的(de)是(shi)，它的(de)溫(wen)度控(kong)(kong)(kong)制(zhi)(zhi)方式是(shi)相(xiang)反的(de)，可以利用溫(wen)度控(kong)(kong)(kong)制(zhi)(zhi)器(qi)(qi)的(de)常閉開關來(lai)完(wan)成該任(ren)務。太陽能(neng)(neng)控(kong)(kong)(kong)制(zhi)(zhi)器(qi)(qi)要(yao)借助小型中間繼電器(qi)(qi)來(lai)實現反向的(de)控(kong)(kong)(kong)制(zhi)(zhi)功能(neng)(neng)，由于當前(qian)應用的(de)很少，這里不做詳細的(de)介紹了。

　　2.防凍控制的考慮

　　此原(yuan)理(li)也可(ke)以(yi)應用到(dao)防凍循環控(kong)(kong)制(zhi)上(shang)，將循環水(shui)(shui)泵(beng)連(lian)接在溫控(kong)(kong)開關(guan)的常開開關(guan)線(xian)路(lu)上(shang)，溫度調整(zheng)在5℃，當集熱器內水(shui)(shui)溫降到(dao)5℃以(yi)下時，集熱水(shui)(shui)泵(beng)啟動，將保溫水(shui)(shui)箱的熱水(shui)(shui)泵(beng)入集熱器，達(da)到(dao)防凍的目的。同理(li)，在電熱帶的應用上(shang)也可(ke)以(yi)采用此方法。機械式溫控(kong)(kong)器，可(ke)靠性好，價格低廉(lian)，是太陽能熱水(shui)(shui)工程控(kong)(kong)制(zhi)的重要元件。參(can)考控(kong)(kong)制(zhi)圖(tu)如圖(tu)5—15。

　　考慮到節約成本，集(ji)熱循環(huan)和防凍循環(huan)可(ke)以共用一個水(shui)泵，但在接入時(shi)要注意兩點：

　　(1)要區(qu)分火線(xian)和零(ling)(ling)線(xian)，火線(xian)接火線(xian)，零(ling)(ling)線(xian)接零(ling)(ling)線(xian)(零(ling)(ling)線(xian)可以共(gong)用);

　　(2)對(dui)控制柜采用三相(xiang)電源(yuan)接入的(de)，要考慮(lv)火線的(de)相(xiang)序，U相(xiang)接U相(xiang)，V相(xiang)接V相(xiang)，不能接錯，否(fou)則將損壞(huai)循環(huan)電機等。

　　(3)對電工不太(tai)熟悉(xi)的(de)(de)讀者，建(jian)議設立(li)獨立(li)的(de)(de)防凍循環水泵，這樣不容易混淆，修理(li)時也方便，此法要加入單相閥將水道做一(yi)定的(de)(de)隔(ge)離(li)。

　　3.溫差循環

　　溫(wen)(wen)(wen)(wen)差(cha)(cha)控(kong)(kong)(kong)制(zhi)的(de)(de)(de)(de)(de)方法就是(shi)在(zai)(zai)(zai)太陽(yang)能(neng)(neng)(neng)集(ji)熱器(qi)(qi)的(de)(de)(de)(de)(de)溫(wen)(wen)(wen)(wen)度最高(gao)(gao)點(dian)上(shang)，盡量靠近儲熱水(shui)箱，安裝高(gao)(gao)溫(wen)(wen)(wen)(wen)的(de)(de)(de)(de)(de)溫(wen)(wen)(wen)(wen)度探頭(tou)，在(zai)(zai)(zai)循(xun)環保溫(wen)(wen)(wen)(wen)水(shui)箱的(de)(de)(de)(de)(de)溫(wen)(wen)(wen)(wen)度低(di)(di)(di)點(dian)上(shang)安裝低(di)(di)(di)溫(wen)(wen)(wen)(wen)探頭(tou)，這樣(yang)(yang)，當(dang)太陽(yang)能(neng)(neng)(neng)集(ji)熱器(qi)(qi)工(gong)作時(shi)，就會產(chan)生一個(ge)(ge)高(gao)(gao)溫(wen)(wen)(wen)(wen)和低(di)(di)(di)溫(wen)(wen)(wen)(wen)的(de)(de)(de)(de)(de)溫(wen)(wen)(wen)(wen)度差(cha)(cha)，我們可(ke)以設(she)定(ding)一個(ge)(ge)溫(wen)(wen)(wen)(wen)度差(cha)(cha)值，比如50c，當(dang)高(gao)(gao)溫(wen)(wen)(wen)(wen)點(dian)和低(di)(di)(di)溫(wen)(wen)(wen)(wen)點(dian)溫(wen)(wen)(wen)(wen)度差(cha)(cha)達到設(she)定(ding)值時(shi)，比如50c，則控(kong)(kong)(kong)制(zhi)器(qi)(qi)通知循(xun)環水(shui)泵將集(ji)熱器(qi)(qi)中的(de)(de)(de)(de)(de)熱水(shui)泵入(ru)儲熱水(shui)箱中，直到高(gao)(gao)低(di)(di)(di)溫(wen)(wen)(wen)(wen)探頭(tou)的(de)(de)(de)(de)(de)溫(wen)(wen)(wen)(wen)度差(cha)(cha)低(di)(di)(di)于設(she)定(ding)的(de)(de)(de)(de)(de)溫(wen)(wen)(wen)(wen)度時(shi)，水(shui)泵停(ting)(ting)止工(gong)作。溫(wen)(wen)(wen)(wen)控(kong)(kong)(kong)器(qi)(qi)的(de)(de)(de)(de)(de)溫(wen)(wen)(wen)(wen)差(cha)(cha)停(ting)(ting)止溫(wen)(wen)(wen)(wen)度也采用(yong)回差(cha)(cha)控(kong)(kong)(kong)制(zhi)辦(ban)法，一般比設(she)定(ding)溫(wen)(wen)(wen)(wen)度低(di)(di)(di)2～3℃左右，這樣(yang)(yang)才(cai)不會造成水(shui)泵因頻繁啟動而燒毀等事故。一般的(de)(de)(de)(de)(de)溫(wen)(wen)(wen)(wen)差(cha)(cha)控(kong)(kong)(kong)制(zhi)器(qi)(qi)由于采用(yong)微機芯(xin)片控(kong)(kong)(kong)制(zhi)，當(dang)然(ran)也就不在(zai)(zai)(zai)乎加上(shang)回差(cha)(cha)調功能(neng)(neng)(neng)了，所以溫(wen)(wen)(wen)(wen)差(cha)(cha)控(kong)(kong)(kong)制(zhi)器(qi)(qi)一般都有調控(kong)(kong)(kong)回差(cha)(cha)功能(neng)(neng)(neng)。

　　未完待續……

　　浩通節能設備有限公司專業為工廠、學校，酒店等場所提供太陽能熱水器│太陽能+空氣能熱泵│空氣能熱水器│空氣能熱泵│空氣源熱水器│空氣源熱泵│熱泵熱水工程方案咨詢設(she)計報價安(an)裝服務。

　　全國服務熱線：400-642-8850

浩通熱水工程官網文章地址：//cfaitao.com.cn/news/tyn/tynkzxtdwkzfdkzwckz.html

----------------------------分隔線----------------------------

上一篇：太陽能熱水工程控制系統——水位水溫傳感器(二) 下一篇：太陽能熱水工程常見故障和排除方法