蓄能供热型太阳能集热器结构优化

提出一种蓄能供热型太阳能集热器,将太阳能真空集热管、重力热管蒸发段、热泵蒸发器和相变材料集于一体,可有效克服太阳辐射波动性影响,结构紧凑,集热效率高. 利用FLUENT软件模拟研究蓄能供热型太阳能集热器内相变材料的蓄放热特性. 对比分析集热器内不同结构:重力热管蒸发段和蒸发器管路采用并排布置或三角布置时相变材料的温度场和速度场,结果表明,并排布置方式优于三角布置方式,相变材料完全熔化时间可缩短22.6%,完全熔化时相变材料储存的热量更多. 研究集热器倾斜角度对相变材料蓄热/释热过程的影响,结果表明,蓄热过程倾斜放置比竖直放置时相变材料的完全熔化时间缩短了约28%,而释热过程完全熔化时间不受倾斜角度的影响. 最后研究了相变材料的相变温度和相变潜热对相变过程的影响,结果表明,在能够满足相变材料蓄热所需的相变温度范围内,应选取相变温度较低、相变潜热较大的相变材料.

Structural Optimization of Energy Storage and Heating Solar Collectors

An energy storage and heating type solar collector is proposed,which integrates a solar vacuum heat collector tube,a gravity heat tube evaporation section,a heat pump evaporator and a phase change material. The collector can effectively overcome the fluctuation effect of solar radiation,and has a compact structure and high heat collection efficiency. The FLUENT software is used to simulate and study the heat storage and release characteristics of the phase change material in the energy storage and heating solar collector. The different structures in the collector,which are the temperature field and velocity field of the phase change material,are compared and analyzed when the evaporation section of the gravity heat pipe and the evaporator pipeline are arranged side by side or in a triangle. The results show that the side-by-side arrangement is better than the triangle arrangement,that the complete melting time of the phase change material can be shortened by 22.6%,and that the phase change material stores more heat during complete melting. The effect of the inclination angle of the collector on the heat storage/heat release process of the phase change material is studied. The results show that the complete melting time of the phase change material is shortened by about 28% when the heat storage process is inclined and placed vertically,and that the melting time is not affected by the tilt angle. Finally,the effects of the phase change temperature and the latent heat of phase change on the phase change process of the phase change material are studied. The results show that in the phase change temperature range that can meet the heat storage requirements of the phase change material,the phase change materials with large latent heat of change with lower phase change temperature and larger latent heat of change should be used.