Abstract:

In order to enhance the cold storage performance of R134a hydrate preparation system, the effects of different pore density and different material thickness on the cold storage performance of three kinds of porous foam materials (silicon carbide foam ceramic, aluminum foam and copper foam) were studied, and the optimization of the system was studied by Fluent. The results show that when the charging pressure is 0.25 MPa, the addition of porous foam materials with different pore densities (10, 20, 30 PPI) can promote the cold storage performance of R134a hydrate test rig, but with the increase of pore density, the cold storage performance of the three materials systems decreases. The experimental results show that when the pore density is 10 PPI, the hydrate cold storage characteristics are optimal when the material thickness is 30 mm. And when the material is copper foam, the system's precooling time and cold storage time are the lowest, 35.80 min and 42.61 min respectively, the total cool storage capacity is 937.71 kJ, the cool storage rate is 0.364 kW, and the mass of hydrate formation is 0.992 kg. The numerical simulation results show that when the inlet velocity of diffuser is 8 m/s, the two-phase flow performance in reactor is optimal, which is more conducive to the formation of R134a hydrate around porous media.

Key words: cold storage, charging pressure, porous media, gas holdup, hydrate

摘要：

为了强化R134a水合物制备系统的蓄冷性能，研究了三种泡沫多孔材料体系（碳化硅泡沫陶瓷、泡沫铝、泡沫铜）下不同的孔密度和不同材料厚度对实验台蓄冷特性的影响，并使用Fluent对系统进行优化研究。实验表明充注压力为0.25 MPa时，添加不同孔密度（10、20、30 PPI）的泡沫多孔材料均能对R134a水合物实验台的蓄冷性能具有促进作用，但随着孔密度的增大，三种材料体系的蓄冷特性都随之降低。实验结果表明，当孔密度同为10 PPI，材料厚度为30 mm时，水合物蓄冷特性达到最优。且材料为泡沫铜时，系统的预冷时间和蓄冷时间达到最低，分别为35.80 min和42.61 min；总蓄冷量为937.71 kJ、蓄冷速率为0.364 kW，水合物生成质量为0.992 kg。数值模拟结果表明，当散流器入口流速为8 m/s时，反应釜内的两相流性能最佳，更有利于R134a水合物围绕着多孔介质大量生成。

关键词: 蓄冷, 充注压力, 多孔介质, 气含率, 水合物