考虑余热利用的工业园区全局热集成

Total industrial park site heat integration with waste heat utilization

考虑工业园区中的余热再利用,将公用工程系统、换热器网络(heat exchanger network, HEN)、制冷系统进行同步综合是降低园区整体能耗的关键。针对该问题,该文提出了一个基于数学规划思想的工业园区全局热集成方法。通过分析热量相关系统间的潜在作用关系,建立了一个经工艺流股余热发生蒸汽,并考虑厂际间HEN、热公用工程系统、循环水系统和吸收式制冷循环(absorption refrigeration cycle, ARC)系统耦合关系的全局热集成超结构,通过构建混合整数非线性规划(mixed-integer nonlinear programming, MINLP)数学模型,以经济性最优为优化目标设计园区内流股的换热匹配、多等级蒸汽的分配权衡、以及冷冻水和冷却水的使用。其中,过程热流股发生的蒸汽与公用工程蒸汽作为园区热源为过程冷流股和ARC系统提供多等级蒸汽;冷却水与冷冻水系统作为园区冷源满足工艺热流股和ARC系统的制冷需求。最后,通过案例计算分析了余热利用对园区全局能量分配的影响。结果表明:考虑余热利用的全局热集成方法能显著降低园区总体能耗及投资,证明了所提方法的有效性。

Integrated utility systems, heat exchanger networks(HEN), and refrigeration systems can significantly improve waste heat utilization in industrial parks. This paper presents a programmed approach for total site heat integration. A site heat integration model was developed that includes interactions between the inter-plant HEN, steam system, cooling water system, and absorption cooling(ARC) system and was formulated as a mixed-integer nonlinear programming(MINLP) model. In this model, steam generated from the hot process stream and the utility steam are used as a heat source to heat the cold stream and drive the ARC system. The cooling water and chilled water systems are then used as cooling sources to meet the cooling requirements of the ARC system and the hot stream. Analyses of three plants shows the effect of waste heat utilization on the total energy distribution at the site. The results show that this method significantly reduces the energy consumption and investment by making the overall system configuration more efficient.