共查询到19条相似文献,搜索用时 78 毫秒
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1kW碟式太阳能行波热声发电系统 总被引:1,自引:0,他引:1
碟式太阳能行波热声发电是近年来兴起的新型热发电技术,具有可靠性好、潜在效率高、分布灵活等优点。本文介绍了正在研制的一套1 kW碟式太阳能行波热声发电系统。该系统利用碟式集热器收集太阳辐射热量,通过高温热管将热量传输到发动机热端,再采用行波热声发电机进行热-电转换。初步调试采用高频加热模拟太阳能,以3.5 MPa氦气为工质、加热温度为751℃和798℃时分别实现了116 W和255 W的电功输出。实验验证了系统的可行性。目前系统的安装调试仍在进行中,相关的实验结果将在后续的文章中进行报道。 相似文献
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采用计算流体动力学(CFD)方法,对高频驻波热声发动机和热声斯特林发动机实验系统分别进行了二维和三维数值模拟。计算模型具有与实验系统相同的几何结构、尺寸和运行工况。对计算模型的有效性进行了研究,表明实现有限换热条件的板叠实物模型适合驻波热声发动机的模拟,而实现局域热平衡的多孔介质模型适合热声斯特林发动机的模拟。计算结果成功观测到了非线性的自激振荡演化过程,捕捉到了两种发动机的不同非线性现象。计算结果分别给出了两种热声发动机内部的声场分布特性和复杂流场。计算结果与实验结果的对比验证了CFD方法对高频驻波热声发动机和热声斯特林发动机模拟的有效性。 相似文献
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Maximum power output of a class of irreversible non-regeneration heat engines with non-uniform working fluid, in which heat
transfers between the working fluid and the heat reservoirs obey the linear phenomenological heat transfer law [q ∝ Δ(T
−1)], are studied in this paper. Optimal control theory is used to determine the upper bounds of power of the heat engine for
the lumped-parameter model and the distributed-parameter model, respectively. The results show that the maximum power output
of the heat engine in the distributed-parameter model is less than or equal to that in the lumped-parameter model, which could
provide more realistic guidelines for real heat engines. Analytical solutions of the maximum power output are obtained for
the irreversible heat engines working between constant temperature reservoirs. For the irreversible heat engine operating
between variable temperature reservoirs, a numerical example for the lumped-parameter model is provided by numerical calculation.
The effects of changes of reservoir’s temperature on the maximum power of the heat engine are analyzed. The obtained results
are, in addition, compared with those obtained with Newtonian heat transfer law [q ∝ Δ(T)]. 相似文献
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热声发动机的起振过程是一个产生并维持自激振荡的过程, 研究热声自激振荡机理有助于进一步了解热声效应的实质. 根据热声网络理论, 建立了驻波热声发动机的整机网络. 将热声网络比拟成电网络, 利用厄米特式计算了输入热声网络的视在功流, 功流平衡对应自激, 在角频率虚部为零的情况下计算了热声发动机的阈值温度和运行频率. 结果表明, 计算值与实验值符合得较好, 充气压力与阈值温度和运行频率的耦合关系大致相同. 所得结论有助于进一步探究热声效应机理以及热声发动机系统的优化设计. 相似文献
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Helmholtz resonator is often used to reduce noise in a narrow frequency range. To obtain a broader noise attenuation band, combing several resonators is a possible way. This paper presents a theoretical study of sound propagation in a one-dimensional duct with identical side-branch resonators mounted periodically. The analysis of each resonator was based on a distributed-parameter model that considered multi-dimensional wave propagation in its neck-cavity interface. This model provided a more accurate prediction of the resonant frequency of the resonator than traditional lumped-parameter model. Bloch wave theory and the transfer matrix method were used to investigate wave propagation in these spatially periodic resonators. The results predicted by the theory fit well with the computer simulation using a three-dimensional finite element method and the experimental results. This study indicates that the wave coupling in this periodic system results in the dispersion of the frequency band into the stop and the pass bands. The long-term significance is that periodic resonators may more effectively control noise in ducts by broadening the bandwidth they attenuate and increasing the magnitude of sound attenuation. 相似文献
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Linear thermoacoustic theory is currently well accepted for simulating thermoacoustic systems, and correction is used to reduce the discrepancy between calculations and experimental results for turbulent flow. In order to calculate passive tube systems and make linear thermoacoustic theory coincide closely with experiments, a passive network model based on fluid network theory is derived. An amendment method is proposed to further correct for turbulence by amending thermal and viscous penetration depths when the ratio of the tube radius to the viscous penetration depth R/δv is large. The experiments have been done to verify the model in the acoustic amplifier, Helmholtz resonator, and inertance tube. In addition, the mechanisms of such tubes are further analyzed based on the model. 相似文献
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分析和研究了频率对热声制冷机声压、温差和声功的影响 ;使用网络模型计算的结果与实验结果相吻合 ;该研究也是对网络模拟和声功测量方法的验证。 相似文献