为了研究变速运动对相变胶囊的强化传热效果，选用十六烷为相变材料，黄铜为壳制备圆柱形相变胶囊，利用曲柄摇杆往复装置实现变速运动并搭建实验平台；实验设计相变胶囊在蓄、放热过程中温度的变化范围为10~30 ℃，变速运动的方向为沿胶囊轴向或径向往复运动，振幅为6~12.5 mm，频率为1.55~3.78 Hz，通过测量均匀分布在胶囊内部轴线上8个测点的温度数据分析变速运动的方向、振幅和频率对胶囊蓄、放热效果的影响。实验结果表明：变速运动显著增强了相变胶囊的换热效果，在实验范围内，相比于静止状态，换热系数最大可增加35.6%；胶囊沿径向运动比沿轴向运动强化换热效果更好，沿径向运动时换热时间最多可缩短26.7%；不同工况下胶囊的放热时间均高于蓄热时间，增加振幅和频率可以有效提高蓄、放热效率且对蓄热过程的影响更加显著。

In order to study the effect of variable speed motion on heat transfer enhancement of phase change capsules, the cylindrical phase change capsules were prepared by using hexadecane as phase change material and brass as shell. The crank rocker reciprocating device was used to realize the variable speed movement and build the experimental platform; phase change capsules were designed experimentally in the process of charging and discharging of the temperature range of 10-30 ℃, with the direction of variable speed movement along the capsule axial or radial reciprocating motion, amplitude of 6-12.5 mm, and frequency of 1.55-3.78 Hz. The influence of variable motion direction, amplitude and frequency on capsule charging and discharging effects was analyzed by measuring the temperature data uniformly distributed at eight measuring points on the inner axis of capsule. The experimental results show that the heat transfer of phase change capsules is significantly enhanced by variable speed motion. Compared with the static state, the heat transfer coefficient can be increased by up to 35.6% in the experimental range; the effect of enhanced heat transfer is better when the capsule moves along the radial direction than that along the axial direction, and the heat transfer time can be shortened by 26.7% at most; the discharging time of capsules under different working conditions is higher than the charging time. Increasing amplitude and frequency can effectively improve the efficiency of charging and discharging, and has a more significant impact on the charging process.

TK02

国家自然科学基金（52276157）