采用两种中间介质的工业园区厂际余热集成

发挥园区集群效应,借助中间介质回路将工业园区中各单厂内的余热于厂际间进一步回收利用,能够显著提高园区整体能源效率。其中,中间介质回路的设置与介质的选择将关系到整个余热回收系统的最优设计与节能效果。因此,不同于目前研究仅采用一种中间介质的集成策略,同时选用热水和导热油为介质开展厂际余热集成研究。提出耦合介质与厂内流股换热及介质流股在厂际间分配的换热器网络超结构,以年度总费用最小为目标建立MINLP热集成数学模型,优化获得包含介质回路结构与厂内换热器网络结构等内容的园区余热集成结果。最后,在一个包含3个厂的厂际余热集成案例中,分别研究了单种介质单回路、单种介质双回路及双种介质双回路3种情况,通过对比验证了所提方法的有效性。

Inter-plant waste heat integration for industrial park using two medium fluids

Considering the cluster effect of industrial park, it is expectable that could improve energy efficiency of the entire park by recovering the waste heat in each single plant via inter-plant medium fluids which absorb heat in some plants and release heat into other plants. Obviously, the selection of heat exchange medium and the setting of medium heat recovery loop will highly affect the optimal design of the waste heat recovery system and the energy-saving effect. Thus, other than single medium integration strategy, this work uses both hot water and thermal oil as mediums to implement the inter-plant waste heat integration. A heat exchanger network (HEN) superstructure coupling the matches between medium fluids and inner-plant process streams and the allocation of medium streams across plants is proposed. Accordingly, a mixed-integer non-linear programming (MINLP) model is formulated for network optimization aiming at the target of minimum total annual cost. At last, an example involving three plants is studied in three synthesis cases (single medium-single loop, single medium-dual loops, and dual mediums-dual loops). The effectiveness of the proposed method was verified by comparison.