本研究採用能量法的觀點，發展出多孔海洋放流管內部水力計算程式，能夠計算海洋放流管內部各個參數分佈。另外，搭配遺傳演算法，以海洋放流管硬體建置之幾個主要參數：擴散管長度、豎管數目、擴散管管徑、排放口直徑為變數，探討在不同的適合度函數條件下，海洋放流管建置之優化解。 研究結果顯示：(1) 不當的海洋放流管建置參數組合，將使加壓站的操作成本大量增加，而這是前人所未加以考慮的；(2) 隨著設計操作年限的增加，優化所得之年操作成本隨著減少；(3)若考慮之設計操作年限很短，可考慮採用單排放口之海洋放流管，以降低海洋放流管興建成本，但這會造成加壓水頭升高，單年加壓站操作成本亦提高；而若考慮之設計操作年限增長，可考慮採用較多孔數之海洋放流管，可達到降低加壓水頭、加壓站操作成本的效果；(4) 非等管徑擴散管在流速分佈均勻度以及加壓水頭的考量下，均優於等管徑擴散管；(5)豎管數目愈少，等值排放口直徑愈小，擴散管直徑愈小，此三種情形都會造成加壓水頭的大量增加；(6) 豎管數目愈少，等值排放口直徑愈小，豎管間距愈大，此三種情形都會造成稀釋率上升；(7)豎管數目愈少，等值排放口直徑愈小，會使出口密差福祿數增加。 The primary purpose of a multiport diffuser is to distribute the effluent evenly along the length of diffuser pipe. Besides that, it is also desirable to have the head loss as low as possible so that the available head is sufficient to prevent sea water intrusion and sediment deposition in the diffuser pipe. At the same time, it is favorable to have high port velocity for rapid mixing. In this study, a computation model for the discharge parameters, such as diffuser length, number of risers, diameters of diffuser and port, of multiport diffuser is developed. The optimalization of the above parameters is investigated by using the Genetic Algorithm (GA). The results show that: (1) Inappropriate combination of ocean outfall parameters cause huge influence on the operational cost of pumping station. (2) The pumping cost per each will decrease as the operation year increase. (3) The diffuser with non-uniform diameter has better performance than the uniform diameter diffuser. (4) The pumping head increases as the number of risers, port diameter and diffuser diameter decrease. (5) The dilution rate increases as the number of risers, port diameter decrease and port spacing increases. (6) The densimetric Froude number increases as the number of risers and port diameter decrease. (7) If the effluent experiences a cross flow, the port spacing can be reduced.
