共查询到18条相似文献,搜索用时 218 毫秒
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设计了一种采用热电制冷的并接式空气隙膜蒸馏系统,以热电制冷替代机械式制冷为膜蒸馏过程提供冷量。通过对膜蒸馏过程与热电制冷的匹配研究,给出了最佳匹配工况的基本要求。制作了具有水冷散热热电制冷的膜蒸馏冷腔,对单片热电制冷器采用风冷散冷的制冷性能进行研究,结果表明:一定热端散热强度下,热电制冷膜蒸馏冷腔的冷面温度可满足膜蒸馏运行;当热端循环水进口温度为20℃、流量为100L/h、风机风量为660m3/h、热电制冷器工作电流为5.5A时,热电制冷量为87.1W,制冷效率为1.3,二者均为最大值,且预测相应理论蒸馏通量为40kg/(m2?h)。研究结果为小型太阳能热电制冷空气隙膜蒸馏系统的理论研究和实际应用奠定了基础。 相似文献
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Concentration profiles of trichloroethene were measured in a boundary-layer flow over a heated ceramic surface. Raman scattering was excited with the fifth harmonic of a Nd:YAG laser at 213 nm. This wavelength took advantage of a resonance in the trichloroethene molecule to significantly enhance the C2HCl3 scattering cross section. The resonant Raman system was calibrated in a heated flow. The optical system was optimized so that measurements could be obtained close to the solid surface, normally a significant challenge for a spontaneous Raman-scattering setup. Measured concentrations indicated the lack of catalytic activity on a bare alumina surface. However, the results showed that a surface that was coated with Cr2O3-based zeolite was catalytically active. 相似文献
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O. A. Evtikhieva 《Measurement Techniques》2006,49(5):466-471
The problem of determining the trajectories of geometrical optical rays for a model of a laser plane in a spherical thermal
boundary layer is solved and equations of the projection of the laser plane passing through the layer are obtained. Qualitative
variations in the pattern of refraction of rays and the projection of the laser plane for two models of the boundary layer
are studied. It is shown that under definite conditions, the results of measurements of the parameters of this projection
may be used to calculate the temperature field in the layer.
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Translated from Izmeritel’naya Tekhnika, No. 5, pp. 35–38, May, 2006. 相似文献
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T. Fang 《Acta Mechanica》2003,163(3-4):161-172
In this paper, the thermal boundary-layer problem of a semi-infinite flat plate moving in a constant velocity free stream is studied. The similarity equations with viscous dissipation for the thermal boundary-layer are derived and solved by numerical techniques. Under some specific conditions, the thermal boundary-layer similarity equation can be integrated analytically. The results are analyzed for very small Eckert number case and large Eckert number case. It is found that, for the two cases, wall heat fluxes will increase with the increase of the velocity ratio . With increasing Eckert number, the viscous dissipation heating will become dominant. However, for the Prandtl number when the Eckert number is small, it is found that wall heat fluxes will increase with increasing Prandtl number only for a certain range of velocity ratio . For the other range, the wall heat fluxes will have a maximum at a certain Prandtl number, and, when the Prandtl number is larger than the critical value, wall heat fluxes will decrease with increasing Prandtl number. Some examples of the lower solution branch are also presented to compare with the upper solution branch. It is found that the lower solution branch will result in lower heat fluxes at the wall. 相似文献
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太阳能膜蒸馏淡化水系统研究进展 总被引:1,自引:0,他引:1
在能源紧张和水资源匮乏的时代背景下,利用太阳能驱动膜蒸馏系统来淡化海水和苦咸水成为一项重要的水处理技术.为了提高膜蒸馏通量,使用了旋转切向入流的方式来强化传质过程,并对其作了深入的数值模拟和机理研究.在空气隙膜组件结构上做了进一步的改进,其通量与原有膜组件通量接近,但易于加工制作和可多种方式组合使用.为提高太阳能热水系统的性能,开展了集热器性能的实验研究,并应用FLUENT软件对全玻璃真空管集热系统进行三维数值模拟计算.太阳能膜蒸馏的实验表明在呼和浩特夏季,完全可以利用太阳能驱动膜蒸馏系统全天工作. 相似文献
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对太阳能膜蒸馏热工质加热系统进行了简化,建立加装导流板的全玻璃太阳能膜蒸馏热工质加热系统的物理模型,该模型包括全玻璃太阳能集热系统和膜蒸馏热腔两部分,提出二者的耦合集成点,得出耦合边界条件及其非稳态流动的设定方法,建立了太阳能膜蒸馏系统的三维非稳态CFD(计算流体动力学)计算模型,得出求解方法及思路,得到太阳能集热器联接管出口流体温度和流量的变化规律,与膜蒸馏热腔模型耦合计算,得出非稳态情况下膜通量与太阳能辐照强度的变化规律,为下一步太阳能利用与膜蒸馏的耦合优化奠定基础. 相似文献