太阳能辐射强度随时间发生变化，造成蓄热单元入口处传热流体温度呈现非稳态变化。为了分析非稳态的入口温度对相变材料蓄热特性的影响，假设传热流体入口温度1h内随时间呈线性变化，并且1h内的平均温度恒定在60℃。讨论了入口温度随时间线性增加及线性降低两种变化形式，对相变材料的熔化速率、熔化分数、蓄热量、固液界面位置等参数的影响。结果表明，当1h内平均入口温度不变，而初始入口温度在30～90℃的范围内变化时，随初始入口温度增加，尽管熔化速率增加，熔化时间从42．75min减小到20．58min；但1h内的总蓄热量却从72．6kW减小到45．3kW。
The temperature of heat transfer fluid （HTF） at the inlet of thermal storage unit presents non-steady state characteristics due to the solar intensity changing with time. In order to analyze the effects of non-steady state inlet temperature on the performance of phase change thermal energy storage unit, the inlet temperature is assumed as linear variation with time and the average temperature in an hour is set to 60℃. Then the effects of inlet temperature linear increase or linear decrease over time on the melting rate, melting fraction, thermal storage capacity, solid-liquid interface location were numerically studied. The results show that both the melting time and thermal energy storage capacity in an hour decrease with the increase of initial HTF inlet temperature. The initial inlet temperature increasing from 30℃ to 90℃ will lead to the melting time decreasing from 42.75 min to 20.58 min and the total TES capacity in an hour reducing from 72.6 kJ to 45.3 kJ.
参考文献
| [1] | Atul Sharma;Lee Dong Won;D Buddhi;Jun Un Park .Numerical heat transfer studies of the fatty acids for different heat exchanger materials on the performance of a latent heat storage system[J].Renewable energy,2005(14):2179-2187. |
| [2] | Hamid El Qarnia .Numerical Analysis Of A Coupled Solar Collector Latent Heat Storage Unit Using Various Phase Change Materials For Heating The Water[J].Energy conversion & management,2009(2):247-254. |
| [3] | Hamid Ait Adine;Hamid El Qarnia .Numerical analysis of the thermal behaviour of a shell-and-tube heat storage unit using phase change materials[J].Applied mathematical modelling,2009(4):2132-2144. |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%