以數學規劃法做用水網路最適化設計之研究

Abstract

本研究針對工廠用水網路設計提供了一個數學方法，同時考慮了 滿足所有製程用水單元需求的最適化水網路設計，以及最適化的污水排放。 另外，在水網路型態上，也將再生再利用和再生再循環利用水網路，兩者不同型態的水網路設計， 詳加說明，並利用兩個簡單的例子加以分辨其水網路型態的不同。 而這個以超結構為背景數學模式建構，包含了許多實際操作的限制式，例如 供應水流量限制，操作成本，污水處理成本，以及管線成本等等， 最後將產生一個混合整數非線性規劃的問題；為了求得最適化水網路設計結構與設計成本考量上的平衡 ，本研究提出了一個不同設計策略，分別對最適化供應水使用量的水網路設計，以及最適化總成本的水網路設計 做分析比較。最後以本研究所建立的數學模式，對三個不同目標需求的工廠製程做製程用水網路最適化模擬。

A mathematical programming approach for the water networks design in any chemical plant is developed in this paper. This approach considers simultaneously the optimal water networks to satisfy water-using unit demands and optimal treatment of effluent streams. Concept of regeneration reuse and regeneration recycling water networks is explained and distinguished in this method. The based on superstructure mathematical programming approach, which includes many practical operating constraints, flowrate limitations of water supply, operating costs, treatment costs, and piping and sewer costs, will result in a mixed-integer nonlinear programming problem. Complex trade-off involving optimal water networks design structure, as well as design costs has been included in this MINLP problem. Therefore, a different design strategy is presented in this study, and there are analytic comparisons between final water-using network designs for optimal water supply flowrates and optimal total annual cost. Furthermore, three water-using processes having different design objectives are used to demonstrate this approach.