An integrated system-level and component-level optimization of heat transfer systems based on the heat current method. (March 2019)

• Record Type: Journal Article
• Authors: Liu, Di; Chen, Qun; He, Ke-Lun; Chen, Xi
• Is Part Of: International journal of heat and mass transfer. Volume 131(2019)
• Page Start: 623
• Page End: 632
• Publication Date: 2019-03
• Subjects: Energy conservation -- Heat transfer system -- Multi-level optimization -- Heat current method -- Structural parameters; Heat -- Transmission -- Periodicals; Mass transfer -- Periodicals; Chaleur -- Transmission -- Périodiques; Transfert de masse -- Périodiques; Electronic journals; 621.4022
• DOI: 10.1016/j.ijheatmasstransfer.2018.11.083
• Languages: English
• ISSNs: 0017-9310

Abstract

Highlights: Propose a multi-level nested optimization strategy for heat transfer systems. Optimize HTS and heat exchangers collaboratively at both system- and component-levels. Optimal trade off heat transfer and flow resistance for the best overall HTS performance. Compact heat exchangers benefit HTSs with long distance heat transportation. Abstract: Heat transfer system (HTS) optimization is a key for energy conservation. However, optimization of the structural/operating parameters of HTSs and the geometrical structures of single heat exchangers are usually separate and independent. Based on the heat current method together with computational fluid dynamic simulation, this paper optimizes the fluid flow rates and the heat transfer areas in a HTS with prescribed plate spacing of heat exchangers to minimize the total pumping power consumption. Then, by applying the downhill simplex search algorithm, a multi-level nested strategy is developed to optimize the plate spacing of heat exchangers simultaneously. The optimized results show that when the heat transfer rate is 1300 W, the minimum total pumping power consumption is 18.42 W, the optimal heat transfer areas of each heat exchanger are 0.046, 0.076 and 0.058 m 2, respectively, and the optimal plate spacing of the studied heat exchanger is 3.5 mm. Meanwhile, the multi-level collaborative optimization reduces the total power consumption by 27% comparing that regardless of plate spacing optimization. Besides, larger flow resistances of working fluids in pipeline need more compact heat exchangers with smaller plate spacing for energy conservation.