Waste thermal energy harvesting from a convection-driven Rijke–Zhao thermo-acoustic-piezo system
Waste thermal energy harvesting from a convection-driven Rijke–Zhao thermo-acoustic-piezo system
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DOI：
10.1016/j.enconman.2012.09.025
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发表时间：
2013-02
影响因子：
10.4
通讯作者：
Dan Zhao
中科院分区：
文献类型：
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作者：
Dan Zhao
在这项工作中，对流驱动的Rijke-Zhao热声压电系统的设计和实验测试，以证明其潜在的收获热能。为此，开发了一个非线性理论模型来模拟本系统中的能量转换过程，即热-声-电。与传统的传导驱动的热声转换器，我们目前的系统不涉及热交换器和堆栈。当热源被放置在具有两个分叉子分支的Rijke-Zhao管中时，产生了自持热声振荡。在分叉分支中产生的声场是显著不同的。一个分支与“热”振荡有关。然而，另一种是在环境温度下的“冷”振荡，这使得压电发电机能够实现到分支的末端。为了测量分叉分支中的声场，使用了两个热电偶和麦克风阵列。最大声压级约为139 dB。输出电功率和声能转换效率的测量和比较，从一个类似的，但传导驱动的热声压电系统。据发现，60%以上的电力产生。能量转换效率提高了105%。这些实验结果证实了所开发的Rijke-Zhao热声压电系统是设计简单、低成本、节能的热声系统的宝贵工具。
In this work, a convection-driven Rijke–Zhao thermo-acoustic-piezo system is designed and experimentally tested to demonstrate its potential for harvesting thermal energy. For this, a nonlinear theoretical model is developed to simulate the energy conversion process, i.e. heat-to-sound-to-electricity in the present system. Unlike the conventional conduction-driven thermoacoustic converters, our present system involves no heat exchangers and stacks. As a heat source is placed in a Rijke–Zhao tube with two bifurcating daughter branches, self-sustained thermoacoustic oscillations are generated. The resulting acoustic fields in the bifurcating branches are dramatically different. One branch is associated with ‘hot’ oscillations. However the other is with ‘cold’ oscillations at ambient temperature, which enable a piezoelectric generator being implemented to the end of the branch. In order to measure the acoustic fields in the bifurcating branches, two arrays of thermocouples and microphones are used. The maximum sound pressure level is around 139dB. The output electric power and acoustical energy conversion efficiency are measured and compared with that from a similar but a conduction-driven thermo-acoustic-piezo system. It is found that 60% more power is generated. And the energy conversion efficiency is increased by 105%. These experimental results confirm that the developed Rijke–Zhao thermo-acoustic-piezo system is an invaluable tool in designing a simple, low-cost, energy-efficient thermoacoustic system.