Process plants are typically energy intensive plants and pollutant emission contributors. Energy integration in process plants effectively reduces energy consumption and pollutant emission. In a traditional energy integration concept, a heat exchanger network (HEN) is typically constructed for heat recovery between process streams. However, a large amount of medium-to-low-temperature surplus heat usually occurs in hot streams, where further internal heat integration is impossible, and is inevitably cooled by external cold source. Integrating organic Rankine cycle (ORC) into the process HEN is an effect way in further enhancing the energy recovery. However, the HEN, utility plant, and ORC are traditionally designed and optimized separately or sequentially, resulting in local energy integration or optimization. In the present study, ORC is integrated into a HEN to generate power energy from surplus heat. An improved superstructure is constructed and a mixed integer non-linear programming model is developed for the synthesis and simultaneous optimization of the integration system containing process-process HEN, hot utility-cold stream HEN, process hot stream-ORC HEN, steam utility plant, and cold utility plant. Two case studies of different scale in complexity are elaborated to validate the proposed methodology. Sensitivity analysis of carbon tax and fuel price are finally conducted.

中文翻译：

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换热网络、蒸汽朗肯循环和有机朗肯循环的综合和同时 MINLP 优化

加工厂通常是能源密集型工厂和污染物排放源。过程工厂的能源整合有效地降低了能源消耗和污染物排放。在传统的能源集成概念中，通常构建换热器网络 (HEN) 以实现工艺流之间的热回收。然而，大量的中低温余热通常发生在热流中，内部无法进一步整合热量，不可避免地需要外部冷源冷却。将有机朗肯循环 (ORC) 整合到 HEN 过程中是进一步提高能量回收的有效途径。然而，传统上，HEN、公用设施和 ORC 是单独或顺序设计和优化的，从而导致本地能源整合或优化。在目前的研究中，ORC 被集成到一个 HEN 中，以从剩余的热量中产生电能。构建了改进的上层结构并开发了混合整数非线性规划模型，用于综合和同时优化包含工艺-工艺 HEN、热公用设施-冷流 HEN、工艺热流-ORC HEN、蒸汽公用设施、和冷电厂。详细阐述了两个不同规模复杂性的案例研究来验证所提出的方法。最后对碳税和燃料价格进行敏感性分析。处理热流-ORC HEN、蒸汽电厂和冷电厂。详细阐述了两个不同规模复杂性的案例研究，以验证所提出的方法。最后对碳税和燃料价格进行敏感性分析。处理热流-ORC HEN、蒸汽电厂和冷电厂。详细阐述了两个不同规模复杂性的案例研究来验证所提出的方法。最后对碳税和燃料价格进行敏感性分析。