基于热力学原理,以夹点技术为基础结合数学规划法,采用两步法综合多程换热网络。第一步在多程换热网络热力学分析的基础上优化求解最小温差,计算公用工程用量。第二步将求得的最小温差作为夹点温差,将网络分为夹点之上和夹点之下两个子网络,建立多程换热网络的超结构模型,确定流股匹配并优化网络配置。最后,以换热网络总费用最小为目标,连接两个子网络,权衡设备投资费用和操作费用,综合多程换热网络。该方法基于热力学原理,改进了夹点技术在多程换热网络综合中的应用,进而实现了多程换热网络的自动综合。示例分析证明了本文所提方法的有效性。
According to thermodynamic principle, synthesis of the heat exchanger network (HEN) with multi-pass was performed based on pinch technology, and a two-stage method was presented by using the mathematical programming methodology and pinch technology simultaneously. Firstly, the minimum temperature difference for the multi-pass HEN was optimized based on thermodynamic analysis, and then utility costs were calculated. At the second stage, according to the obtained optimal minimum temperature difference the pinch location was defined, and the corresponding HEN could be divided into two sub-networks: above the pinch point and under the pinch point. Then streams matches were optimized by using the superstructure model for the multi-pass HEN. Consequently, to minimize total cost, the multi-pass HEN was synthesized by balancing capital cost and operation cost. Case studies demonstrated the effectiveness and application prospect of the presented method.