机械振动诱发过冷三水醋酸钠蓄热单元释能特性实验研究  

Experimental Investigation on Discharging Characteristics of Supercooled Sodium Acetate Trihydrate Thermal Storage Unit by Mechanical Vibration

作　　者：杜海翔 周国兵[1] DU Haixiang;ZHOU Guobing(School of Energy,Power and Mechanical Engineering,North China Electric Power University,Beijing 102206,China)

机构地区：[1]华北电力大学能源动力与机械工程学院,北京102206

出　　处：《电力科学与工程》2021年第3期64-71,共8页Electric Power Science and Engineering

基　　金：北京市自然科学基金(3192034,3152022)。

摘　　要：利用钢球敲击和电磁振动器诱发圆角矩形蓄热单元内稳定过冷三水醋酸钠溶液凝固并释放热量,实验研究了蓄热单元表面不同敲击位置以及不同振动频率和输入电压下结晶诱导时间的变化规律。结果表明:17个敲击位置的诱导时间图谱可分为3个层次,即法兰附近、四周边角和单元中间位置,相应平均诱导时间依次为10.2 s,30 s,50 s,尤其处于法兰和边角之间的敲击位置诱导时间最短,均在10s内;经作用强度测试,实验电磁振动装置在单元表面同一位置的振动加速度和位移值约为钢球敲击的1/4;在0~20 Hz内,随着电磁振动频率增加,诱导时间单调递减且变化率整体呈减小趋势,其中20 Hz为较佳触发频率,诱导时间仅为33.3 s;输入电压增大导致振动功率增大,单位时间输入能量增大,诱导进程加快,输入电压为36V的诱导时间约是12 V的1/3。实验结果为机械振动诱发过冷水合盐凝固释能系统设计提供参考。Experiments are performed on the effect of mechanical vibration with a steel ball and electromagnetic vibrator on inducing solidification and heat release of supercooled sodium acetate trihydrate solution in the rounded rectangular heat storage unit.The change regulations of crystallization induction time under different knock positions on the surface of the heat storage unit,different vibration frequencies and input voltages are investigated.The results show that the 17 knock positions can be divided into three groups according to the induction time map,i.e.the vicinity of flange,four edges and the center of the unit,with the corresponding average induction time being 10.2 s,30 s and 50 s respectively.In particular,the induction time for positions between the vicinity of flange and the four edges are the shortest,which are both within 10 s.With the strength test,the vibration acceleration and displacement of the experimental electromagnetic vibration device at the same position on the unit surface are about 1/4 that of the steel ball.As the electromagnetic vibration frequency increases within 0~20 Hz,the induction time decreases monotonically and the rate of change shows a decreasing trend as a whole.Also,20 Hz is the better trigger frequency with the induction time of only 33.3 s.The vibration power is increased for higher input voltage and then the input energy per unit time is larger with shorter induction period.The induction time for an input voltage of 36 V is about 1/3 that of 12 V.The experimental results can provide a reference for the design of energy release system of mechanical vibration inducing supercooled salt solidification.

关 键 词：机械振动 过冷 三水醋酸钠 诱导时间 结晶 

分 类 号：TK02[动力工程及工程热物理] O614.112[理学—无机化学]