Abstract:

In order to study the influence of low temperature working medium on the pulsating heat pipe phase change heat accumulator, a test bed for pulsating heat pipe phase change heat storage and release was built. The cryogenic working medium selected in the experiment is R-134a, the phase change material is paraffin, and the heat accumulator is composed of a group of self-designed pulsating heat pipes. The experimental results show that the normal heat storage and heat release of pulsating heat pipe accumulator can be realized by using R-134a as working medium. In the process of heat storage, the increase of heating power will reduce the heat storage time, but also increase the maximum temperature difference in the heat storage. In the process of heat release, the decrease of cooling water temperature can reduce the solidification time of paraffin. When the water temperature changes from 20℃ to 5℃, the solidification time of paraffin is shortened by 34.8%. The increase of cooling water flow also reduces the setting time of paraffin wax. The water flow is changed from 10 L/h to 40 L/h, and the setting time is shortened by 9.5%. After about three hours of exothermic experiment, the temperature of the phase change material was close to room temperature.

Key words: pulsating heat pipe, phase change, enhanced heat transfer, heat accumulator, paraffin

摘要：

为研究低温工质对脉动热管相变蓄热器的影响，搭建了脉动热管相变蓄放热试验台。实验选用的低温工质为R-134a，相变材料为石蜡，蓄热器由一组自主设计的脉动热管组成。实验结果表明，采用R-134a作为工质能够实现脉动热管蓄热器的正常蓄热和放热。在蓄热过程中，加热功率的增加会减少蓄热时间，但同时也会增加蓄热器内的最大温差；在放热过程中，冷却水温度的降低会减少石蜡的凝固时间，当水温由20℃变为5℃，石蜡的凝固时间缩短了34.8%。冷却水流量的增加也会减少石蜡的凝固时间，水流量由10 L/h变为40 L/h，凝固时间缩短了9.5%。在约3 h的放热实验后，相变材料的温度与室温接近。

关键词: 脉动热管, 相变, 强化传热, 蓄热器, 石蜡