Optimization Model of Cold-Chain Logistics Network for Fresh Agricultural Products —Taking Guangdong Province as an Example

Cold-chain demand of fresh agricultural products is increasing in China, while network layout of cold-chain logistics is in disorder and its cost is huge. To address this problem, this paper casts an optimal model of cold-chain logistics network and tackles it with genetic algorithms. This optimal model takes running total cost of logistics network as the objective, and embeds a nonlinear mixed integer programming including two assignment issues. The model determines optimal layout and logistics management for pre-cooling stations and logistics center for fresh agricultural products. Our main contribution is to consider construction cost and operation cost of cold chain logistics simultaneously. Case study illustrates the effectiveness of the model.

翅片结构对Ca(OH)_(2)/CaO体系热化学储能反应器传热影响的模拟研究

热化学储能是实现太阳能光热发电长期稳定使用的有效方法,热化学储能反应器是实现热量存储和释放的核心装置。在热化学储能系统中,能够通过优化热化学储能反应器的结构提高其效率。因此,对储能反应器的性能、结构进行详细考察有助于反应器形式的改进和性能优化。采用COMSOL Multiphysics软件,模拟研究反应器内部载热流体通道内翅片排布对CaO/Ca(OH)_(2)体系储/放热过程的影响。其中,热载体流道侧的流道采用半圆柱型翅片,翅片采用并列与交错两种排布方式。模拟结果表明,在孔隙率为0.5的条件下,水解过程中,对称式翅片反应器与交错式翅片反应器的反应时间大幅减少,相较于板式反应器,减少了27%的反应时间。在水合过程中,交错式翅片反应器相比板式减少7%的反应时间。