低温相变储能散热器的实验研究

发布时间：2018-08-11 21:28

【摘要】：随着社会经济的发展和民生的改善，传统能源消耗的增长，导致全球气候变化和环境严重污染的问题。本世纪以来，可再生能源的利用越来越受到关注，尤其是太阳能。目前，太阳能利用主要集中在光伏发电和光热利用。光伏利用效率较低，制造过程存在二次环境污染，光热利用尽管效率较高，但是也受间断性和不稳定性等因素的制约。然而，大容量、高效相变储能技术却能有效克服这些缺点。相变储能技术由于温度范围可控、相变过程恒定、储能密度大、易于控制以及性能稳定等优点，已经得到了广泛的应用。相变石蜡作为一种PCM，具有相变储热高、化学稳定性较好、无相分离和价格低廉等优点，因此本文采用石蜡作为PCM。 本课题所用相变储能散热器为自主设计制造，该相变储能散热器由6个储热单元和保温腔体以及热传输管道组成。本文研究了该相变储能散热器中PCM在恒定热源温度的条件下，储能和散热性能的影响因素，绘制出不同热源温度下PCM的储热、散热曲线，并计算了相应储热、散热速率。首先采用差示扫描量热法（DSC）对相变石蜡材料的热物性参数进行测试；其次对PCM在给定热源温度（60℃、65℃、70℃、75℃、80℃、85℃）和给定功率（额定动率为165W的动力泵）条件下进行储热、散热的实验研究；最后分别计算对应热源温度下的储热、散热速率。实验结果表明，在储热过程中，热源温度越高，，储热速率越快；在散热过程中，空气进风口横截面积开启率越大，散热速率越快。PCM的储热过程可分为固相显热储热、熔化潜热储热和液相显热储热三个阶段。在升温过程中，相变储能散热器内的相变石蜡材料温度升高幅度不一致，在固相显热过程中，上部材料温度升高速率大于中下部材料温度升高速率；然而，在散热过程中，相变储能散热器内的相变石蜡材料温度下降趋势总体基本一致。
[Abstract]:With the development of social economy and the improvement of people's livelihood, the increase of traditional energy consumption leads to the problem of global climate change and serious environmental pollution. Since this century, more and more attention has been paid to the utilization of renewable energy, especially solar energy. At present, solar energy utilization is mainly concentrated in photovoltaic power generation and photothermal utilization. Photovoltaic utilization efficiency is low and secondary environmental pollution exists in the manufacturing process. Although the efficiency of photothermal utilization is high, it is also restricted by discontinuity and instability. However, large capacity, high efficiency phase change energy storage technology can effectively overcome these shortcomings. Phase change energy storage technology has been widely used because of the controllable temperature range, constant phase transition process, high energy storage density, easy to control and stable performance. As a kind of PCM, phase change paraffin has the advantages of high heat storage, good chemical stability, no phase separation and low price. Therefore, paraffin wax is used as PCM in this paper. The phase change energy storage radiator used in this paper is designed and manufactured independently. The phase change energy storage radiator consists of six heat storage units, heat preservation chamber and heat transfer pipeline. In this paper, the factors influencing the energy storage and heat dissipation performance of PCM in the phase change energy storage radiator under the condition of constant heat source temperature are studied. The heat storage and heat dissipation curves of PCM at different heat source temperatures are plotted, and the corresponding heat storage and heat dissipation rates are calculated. The thermal properties of phase change paraffin were measured by differential scanning calorimetry (DSC). Secondly, the heat storage and heat dissipation of PCM at given heat source temperature (60 鈩

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