CAJ | 학술논문

蓄热堆积床是否具有高效蓄、放热能力是太阳能热发电技术的关键。根据高温蓄热球与载热流体间的能量平衡，考虑载热流体与蓄热球之间的换热系数，以及相变材料密度的变化，建立了堆积床放热过程的数学模型，并进行了数值模拟，讨论了载热流体流速、相变材料初温、蓄热球半径和孔隙率对蓄热堆积床放热过程的影响。结果表明：载热流体流速越快，蓄热堆积床放热速率越大；孔隙率越小，越不利于蓄热单元散热，但对堆积床整体放热和蓄热有利；相变材料初温仅对显热放热阶段有影响，降低初温，可缩短整体放热时间；蓄热球半径越小，蓄热堆积床放热速率越快，蓄热量也越大。
축열퇴적상시부구유고효축、방열능력시태양능열발전기술적관건。근거고온축열구여재열류체간적능량평형，고필재열류체여축열구지간적환열계수，이급상변재료밀도적변화，건립료퇴적상방열과정적수학모형，병진행료수치모의，토론료재열류체류속、상변재료초온、축열구반경화공극솔대축열퇴적상방열과정적영향。결과표명：재열류체류속월쾌，축열퇴적상방열속솔월대；공극솔월소，월불리우축열단원산열，단대퇴적상정체방열화축열유리；상변재료초온부대현열방열계단유영향，강저초온，가축단정체방열시간；축열구반경월소，축열퇴적상방열속솔월쾌，축열량야월대。
Whether the heating storing packed bed has high efficient heat charge and discharge capability is the key point in solar energy thermal power generation technology.According to energy balance between the high temperature regenerative ball and the heat transfer fluid,the exothermic process model of high temperature heat storing packed bed was established,taking the variations of phase change material (PCM) density and heat transfer coefficient between the heat transfer fluid and heat storage unit into account.The exothermic process of the regenerative packed bed was numerically simulated and the influences of several parameters on the PCM's temperature and heat transfer fluid were discussed,such as the heat transfer fluid velocity,initial temperature of the PCM,heat storage unit radius and accumulated heat packed bed porosi-ty.The results show that,the faster the heat transfer fluid flow rate,the greater the heat release rate.The porosity goes against the heat storage unit's heat dissipation,but is good for piling bed's overall heat release and energy storage.The PCM's initial temperature has obvious influence only on sensible heat releasing stage.Reducing the PCM's initial temperature can shorten the overall heat release time.The smaller the ra-dius of the heat storage unit,the faster the heat release rate and the larger the heat storage amount.