Abstract:

Phase change materials absorb or release heat during phase changing, but its own temperature keep constant. Thus, a box-type energy storage device was developed to regulate the internal temperature of the vehicle and saving energy. Since the suitable environment temperature of human body is 22-26℃ and the phase change temperature of paraffin is 25℃, paraffin is chosen as phase change energy storage material. In this experiment, the melting process and solidification process of paraffin packed in aluminum bottles had been explored. The air velocity of outlet was set at 2.5 m/s. When the air temperature of inlet was 35℃, the paraffin could absorb heat in the melting process and reduce the ambient temperature by 3℃ for 3 hours. When the air temperature of inlet was 10℃, the heat could be released in the solidification process and the ambient temperature was increased by 3℃ above for 3.5 hours. Meanwhile, the temperature change regularity of the graphite composite in the melting and solidification process is explored. Under the condition of constant air velocity, the rate of melting and solidification of graphite composite is related to the temperature difference between phase change material and ambient air. The greater the temperature difference, the faster the phase transition speed and the shorter the phase transition time.

Key words: phase change materials, vehicle energy saving, environment, heat transfer, composites

摘要：

根据相变材料发生相变时可以吸收或者释放大量热量，同时保持自身的温度恒定的性能，设计出箱式储能器用于调节汽车内部气温，达到节能的目的。人体的适宜温度为22~26℃，因此采用相变温度为25℃的相变材料作为相变储能材料，并通过铝瓶封装进行熔化过程和凝固过程的实验研究。结果表明，在出口空气流速2.5 m/s的条件下，当进口温度为35℃时，石蜡在熔化过程中可以吸收环境空气的热量，降低环境温度3℃以上，并且维持3 h。在进口温度为10℃，石蜡在凝固过程可以释出热量，提高环境温度3℃以上，维持3.5 h以上。同时还研究了石墨复合相变材料在箱式储能器里熔化和凝固过程的温度变化规律，在空气流速不变的条件下，石墨复合相变材料熔化和凝固过程的速度与相变材料和环境空气的温差有关，温差越大其相变速度越快，相变完成的时间就越短。

关键词: 相变材料, 汽车节能, 环境, 传热, 复合材料