熔盐与汽液两相流传热特性实验研究

EXPERIMENTAL INVESTIGATION ON HEAT TRANSFER CHARACTERISTICS OF MOLTEN SALT AND VAPOR-FLUID TWO PHASE FLOW

熔盐蒸汽发生器是塔式太阳能热发电站中最为重要的能量转换设备,以太阳盐(质量分数60%NaNO_(3)+40%KNO_(3)混合二元盐,solar salt)为传热工质,实验研究熔盐与汽液两相流在蒸汽发生器中的传热特性。基于实验数据,分析熔盐入口温度及流速、水侧压力及流速等参数对熔盐传热系数的影响规律,并给出熔盐在蒸汽发生器中的传热实验关联式,其最大偏差为±20%。

Molten salt steam generator is an integral heat transfer device in concentrated solar power systems.In this study,a binary salt mixture(60% NaNO_(3) and 40% KNO_(3)) was used as the working substance to study the heat transfer performance of molten salt and vapor-fluid two-phase flow.The experimental results showed that when the tube-side is in the two-phase state,the salt-side heat transfer coefficient increases with increasing water and shell-side flow fluxes;but it decreases with increasing molten salt inlet temperature and water pressure.In addition,based on the experimental data,the multiple linear regression was performed to obtain experimental correlation of heat transfer coefficients with a maximum fitting errors of±20%.