固体蓄热器放热过程模拟分析与实验研究

SIMULATION ANALYSIS AND EXPERIMENTAL STUDY ON EXOTHERMIC PROCESS OF SOLID ACCUMULATOR

为得到工程实际应用中固体蓄热器放热过程的流场分布及流动特性,以工程常用固体蓄热器的放热过程为研究对象,设计一种物理参数非定值的热流固耦合分析方法,通过数值模拟及其实验验证,得到该数值模拟方法的可行性。利用建立的数值模拟方法对固体蓄热器放热过程传热特性进行研究,结果表明:放热过程第1阶段,在低风速循环作用下,放热功率增幅较小,随着蓄热体温度升高,Nu数逐渐降低,并逐渐趋近于等表面热流密度的Nu数,表现出入口段的对流换热特性;放热过程第2阶段,由于风速提升,放热功率显著提高,随着第2阶段的进行,Nu数逐渐增加,对流换热特性较高。

In order to obtain the flow field distribution and flow characteristics of the heat release process of solid accumulator in practical engineering application,the heat release process of solid accumulator commonly used in engineering is taken as the research object,a method of heat fluid-structure coupling analysis with non-constant physical parameters is designed,and its feasibility is verified by numerical simulation and experiment.Using numerical simulation method based on the exothermic process of regenerative heat exchanger with the solid heat transfer characteristics are studied.The results show that in the first stage of the exothermic process,under the effect of low wind speed loop,the heating power is small,as the regenerator temperature Nu number is gradually reduced,and gradually tend to Nu value of the surface heat flow density,showing convective heat transfer characteristics of entrances.In the second stage of the exothermic process,the exothermic power is significantly increased due to the increase of wind speed.With the progress of the second stage,Nu number gradually increases and the convective heat transfer characteristics is high.