狭点结合热泵探讨工业能源整合及再利用.doc

狹點結合熱泵探討工業能源再利用 Industrial energy recovery and reuse using an improved heat pump and pinch technology 研究生：段紀義 Tuan, Chi-I 指導教授：陳庭堅,葉一隆 Chen, Ting-Chien Yeh, Yi-Lung 狹點技術 Pinch Technology 為一種增強能源使用效率方法。可整合工廠製程冷、熱流體並建構系統熱交換網路，評估最適能源使用目標值以提升能源使用效率；但最後工廠仍有廢熱排放而有熱損失。熱泵 Heat Pump 為一個高效率的熱能回收設備，可回收相對低溫處熱能經加壓升溫後再提供給相對較高溫需求處使用以達到節能的目的。傳統熱泵使用冷媒輸送熱能為密閉系統，近幾年開發具熱泵是一種開放系統；而MVR的熱損失及電力使用較少。 本研究將狹點與熱泵結合運用於工業製程，使其產生互補功能以進一步提高能源使用效率。計劃分析二個節能案例，第一個案例研究蒸發濃縮系統節能改善，第二個案例探討鍋爐洩放水同時回收熱能及排放水的可行性。二個分析案例更進一步評估以狹點技術結合不同熱泵的組合案例，以探討各種節能方法對提高能源使用效率及廢熱回收的貢獻度。並使用淨現值法 Net Present Value, NPV 及回收期間法 Payback Period, PP 進行投資效益評估。由研究結果得到：第一個蒸發濃縮案例，狹點技術結合傳統熱泵 案例1-4 的熱能需求與排放可降低15.7與18.9 %，在相同熱能需求下，狹點技術結合具MVR技術改良熱泵 案例1-5 的熱能排放可降低22.6%。第二個鍋爐洩放水案例，狹點技術結合具MVR技術改良熱泵 案例2-3 除熱能回收提高至92.7 %，並可回收81 %排放水。兩個分析案例在節能方面均成效卓著，並且設備投資均可在三年內全數回收。 關鍵字：節能，狹點技術，熱泵，【Abstract】 Pinch technology is one of several effective methods that enhance energy use. It is able to integrate a factory’s hot and cold streams and establish a heat exchange network. The network can assess the optimal energy use to increase efficiency. However, a factory’s upgraded energy use efficiency may require that exhaust heat be discharged, causing heat loss. A heat pump can absorb that heat energy at relatively low temperature. When in thermal balance, the system can save energy. A conventional heat pump using a pressurized refrigerant to transport heat is a closed system. In recent years, an improved heat pump using mechanical vapor re-compression MVR technology has been developed as an open system, with less heat loss and electric demand. In this study, pinch technology was combined with a heat pump in a food factory process to further improve energy use efficiency. Two energy-conserving studies were performed. The first study focused on the vaporized concentration system to improve energy conservation. The second examined the feasibility of simultaneously recovering and reusing heat and water in boiler blow-down water. The two studies were further ana