圆盘布水器对储热水罐性能影响的数值分析

Numerical analysis of influence of flat plate diffuser parameters on performances of hot water storage tank

斜温层储热水罐是大型太阳能集中供暖系统的关键设备,布水器作为斜温层储热水罐重要的元件,其结构参数对罐内斜温层厚度与㶲效率具有重要影响。对圆盘型布水器开孔个数、开孔直径、布水器半径、储热水罐高径比等结构参数对储热性能的影响进行数值分析并设计正交试验。结果表明:各因素对系统㶲效率影响敏感性依次为孔径13.96%、开孔数7.72%、高径比3.92%、圆盘半径0.66%,当孔径为250 mm、开孔数为72个、高径比为1.9、圆盘半径为5 m时,理论上系统㶲效率最大。

The thermocline hot water storage tank is a key part of large-scale solar central heating systems.As an important component of the hot water storage tank,the structure parameters of the diffuser have a significant influence on thermocline thickness and exergy efficiency.In the present study,the influence of structural parameters on the thermal storage performance was simulated and the orthogonal test was designed including the number and radius of openings,the radius of diffuser,and the height-diameter ratio of the hot water storage tank.The results show that the sensitivity of each factor on the system efficiency is 13.96%for the radius of openings,7.72%for the number of openings,3.92%for the height-diameter ratio,and 0.66%for the radius of the diffuser.When the radius of openings is 250 mm,the number of openings is 72,the height-diameter ratio is 1.9,and the radius of the diffuser is 5 m,the system exergy efficiency is the largest in theory.