摘要:高效的城市污水取水技術是原生污水源熱泵系統可靠運行的前提。針對現有相關技術的不足,提出了開式集成污水取水技術。通過定義網眼阻塞系數、污物密度、截面系數等重要參數,建立了表征其取水特性的數學模型,并提出了臨界運行工況的參數條件,考察了各臨界運行參數及不同旋轉周期下網眼阻塞系數等的變化規律。
關鍵詞: 污水源熱泵系統;開式取水;數學模型;運行特性
中圖分類號:TU831.6
文獻標志碼:A
文章編號:16744764(2014)02006206
Abstract:The effective sewage intake technology is prerequisite for the untreated sewage source heat pump system to run steadily. In terms of the insufficiency of current sewage intake technologies, an open sewage intake integration technology is proposed. The mathematical model and the distinguish basis of critical state are established for the sewage intake characteristic by defining some important operating parameters, such as the blocking coefficient, the contamination density and the section coefficient. Furthermore, the change rule of each critical operation parameter is observed along with the various initial parameters. The result can provide the theoretical basis to design the open intake integration technology.
Key words:sewage source heat pump system; open intake; mathematical model; operational characteristics
能源供需矛盾日益突出,建筑能耗巨大,占社會總能耗的30%以上,其中暖通空調的能耗就占據建筑用能的65%以上,因此大力開發利用可再生能源成為建筑用能可持續發展的有效出路之一[13]。城市原生污水這一新型可再生能源,因其分布廣泛、水量巨大[45],當用作熱泵系統的低位熱源時,節能與環保優勢顯著,從而備受各國青睞,成為近年爭相研究與應用的熱點[610]。但由于其成分復雜性,若原生污水熱利用過程直接進換熱器,則污水中所含大尺度污雜物將在短時間內將其堵塞,導致系統不能安全運行[1112]。因此,能夠防堵塞的高效污水取水技術成為熱泵系統研究與應用的關鍵之一。
日本及北歐國家的污水源熱泵系統常采取機械刮剝、人工刷洗等方法來解決污水取水過程中換熱設備的防堵塞問題[57],存在工作量大、運行工況不穩定的弊端。中國近年開發了反沖洗污水取水裝置,實現了穩定、連續取水,并在多個工程中得到了成功的應用,然而該裝置仍存在著取水設備承壓高、取排水內泄露嚴重、濾面過濾負荷大等不足[1314]。因此,研究性能更加優越的污水取水技術成為亟待解決的難點,故本文基于一種新提出的開式集成污水取水技術建立了開式原生污水源熱泵系統,并將對系統取水的數學模型及運行特性作深入分析。
1開式原生污水源熱泵系統
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(編輯王秀玲)