熔融盐斜温层蓄热的热特性研究

THERMAL CHARACTERISTICS ANALYSIS ON THE MOLTEN SALT THERMOCLINE THERMAL ENERGY STORAGE SYSTEM

对熔融盐高温斜温层蓄热过程进行较深入的理论与实验研究,建立熔融盐单相流体斜温层蓄热的瞬态热分析模型,模型考虑熔融盐的变物性。利用Fluent软件,通过求解N-S方程与能量方程,对熔融盐单相流体斜温层蓄热罐在各工况条件下的传热蓄热过程进行数值模拟。研究时间进程、初始条件以及结构尺寸等对蓄热性能的影响。结果表明:斜温层的厚度随时间的推移而增加,达到一定厚度后增加量趋缓;流体进口流速、长径比等是影响有效蓄热容量的主要因素,当进口速度为0.001m/s级、长径比为2∶1时,将减少斜温层厚度。

The numerical simulation and experimental investigation on the heat storage and heat transfer characteristics of the high-temperature thermocline molten salt thermocline thermal energy storage （TES） were presented. The transient thermal analysis model of the single-phase flow molten salt thermocline TES system was set up, which considers the property variations of molten salt. Through solving the N-S equations and energy equation with the Fluent software, the processes of heat storage and heat transfer for the single-phase flow molten salt thermoeline TES system under various operating conditions were simulated, and the influences of the time progress, initial conditions and structural dimensions on the TES performance were analyzed. The results showed the thickness of thermocline layer increases with the passage of time at the initial stage and then the increasing rate drops gradually, the inlet velocity and the length to diameter ratio are the main factors to affect the effective TES capacity, and adopting the inlet velocity at the level of 0. 001m/s and the length to diameter ratio of 2：1 is favorable to the TES performance.