間接有機朗肯循環於化工程序廢熱回收之應用

Abstract

有機朗肯循環是一種將熱轉換為功的循環，其中使用低沸點的有機流體作為工作流體。廢熱回收是有機朗肯循環最重要的發展領域之一，它可以被應用在發電廠會是工廠等程序。某些熱源會含有粒子與硫化物可能會對蒸發器的管線產生損害，例如熱爐產生的廢氣。會建議利用水或是熱傳油來當作中間的循環流體，間接取熱。在這篇論文中，發表了一個整合有機朗肯循環與熱傳油來從其他程序回收廢熱的數學模型，整合有機朗肯循環的超結構考慮了所有在程序熱流、循環熱傳油及有機朗肯循環之間的熱交換器配對可能性。藉由這個超結構，發展出混合整數非線性規劃的模型。我們利用高階的模型程式GAMS來求此混合整數非線性規劃模型的解。以一個原油分餾工廠來當作案例，進行模擬及後續的結果討論，另外也採用回收年限法來評估其經濟效應。

An organic Rankine cycle (ORC) uses a low boiling point organic fluid as a working medium. Waste heat recovery is one of the most important development fields for the organic Rankine cycle (ORC).It can be applied to heat and power plants, or to industrial and farming processes. Some heat sources ,like hot exhausts from furnaces,which contains particles or sulfide might hurt pipes of evaporator.It is suggested to introduce water or heat transfer oil as an intermediate medium.In this paper, a mathematical model is presented for integrate ORC with the heat transfer oil recirculated as a intermediate fluid for recovering waste heat from the background process.A ORC-integrated superstructure considering all possible match of heat-exchange between process hot streams, recirculating hot oil and ORC is proposed.The possibility of several sets of ORC and recirculating hot oil also be concerned in the superstructure.On the basis of this superstructure, the model is formulated as a mixed-integer nonlinear program (MINLP).This MINLP model is designed and solved by a high-level modeling system, General Algebraic Modeling System (GAMS).A case about crude pre-heat train is solved to demonstrate the application of the proposed model for industrial waste heat recovery.Payback year method is applied to evaluate the cost of the additional capital equipment.