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关注了一种以太阳能为驱动热源,基于空气隙膜蒸馏过程的新型海水淡化技术(SP-AGMD),介绍了该技术涉及的膜组件和太阳能集热装置的材质、形式、特点和研究概况,并对比分析了各种膜组件和太阳能集热装置的优势及存在的不足,对国内外的最新研究进展作了重点讨论。将太阳能引入膜蒸馏海水淡化过程大大降低了能耗,有效避免了二次污染而且最大程度节约了运行费用。认为该技术尚处于实验室研究和小型示范阶段,将膜组件与太阳能集热装置更加高效的耦合,进一步降低系统总能耗将是太阳能空气隙膜蒸馏领域的重要方向。 相似文献
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由于吸收膜蒸馏系统的进料液和吸收液的温度非常接近甚至相同,其传热过程无相变热损失,有可能实现能耗较低的膜蒸馏过程,本文尝试开展吸收膜蒸馏法海水淡化研究。首先分别以葡萄糖水溶液和氯化钙水溶液为吸收液进行吸收膜蒸馏海水淡化实验,结果表明氯化钙吸收液时的膜通量明显高于葡萄糖吸收液时的膜通量。其次建立了吸收膜蒸馏过程的质量和热量传递模型,并对模型进行了计算,模型计算值与实验值非常接近。最后对葡萄糖水溶液和氯化钙水溶液分别作吸收液时对传质系数和极化现象的影响进行了计算分析,结果显示,氯化钙水溶液作吸收液时传质系数约为葡萄糖水溶液的1.7倍;且极化现象造成的蒸气压力差减小的值为后者的1/4左右。 相似文献
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由于吸收膜蒸馏系统的进料液和吸收液的温度非常接近甚至相同,其传热过程无相变热损失,有可能实现能耗较低的膜蒸馏过程,本文尝试开展吸收膜蒸馏法海水淡化研究。首先分别以葡萄糖水溶液和氯化钙水溶液为吸收液进行吸收膜蒸馏海水淡化实验,结果表明氯化钙吸收液时的膜通量明显高于葡萄糖吸收液时的膜通量。其次建立了吸收膜蒸馏过程的质量和热量传递模型,并对模型进行了计算,模型计算值与实验值非常接近。最后对葡萄糖水溶液和氯化钙水溶液分别作吸收液时对传质系数和极化现象的影响进行了计算分析,结果显示,氯化钙水溶液作吸收液时传质系数约为葡萄糖水溶液的1.7倍;且极化现象造成的蒸气压力差减小的值为后者的1/4左右。 相似文献
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针对目前管式太阳能蒸馏装置在常压运行时产水率较低的问题,提出了一种可在真空负压条件下连续补水运行的管式蒸馏方法,并在定温及定功率加热条件下,测试了实验样机负压运行时的温度及产水率变化,证明了所提出的负压条件下运行的管式蒸馏方法优于常压运行的一般蒸馏方法。在PT=40 kPa、Qh=200 W定功率加热实验中,空腔传热温差比常压运行时降低约40%;装置全天累计产水量为1.9 kg,比常压运行时产水量增加22.5%。基于稳态实验数据得到了负压修正的空腔传质计算关系式,在此基础上构建了管式蒸馏装置在负压条件运行时的产水率预测模型,其对实验样机全天累计产水预测误差和最大产水率误差分别为2.1%和4%。 相似文献
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太阳能海水淡化新技术综述 总被引:1,自引:0,他引:1
依据太阳能的光效应和热效应对传统的海水淡化进行分类,列举了太阳能与传统蒸馏法与渗析法的结合形式,指出了传统蒸馏法效率不高的原因,重点介绍利用冷凝潜热和提升换热效率的新型高效海水淡化技术以及反渗透的能量回收装置,认为将太阳能与传统海水淡化技术有机结合起来前景广阔,并简述了太阳能收集器的研究现状及先进技术,为太阳能海水淡化技术的进一步研究和发展提供了参考与依据. 相似文献
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膜蒸馏海水淡化研究进展及发展趋势 总被引:2,自引:0,他引:2
海水淡化是解决我国水资源短缺的重要措施之一。膜蒸馏海水淡化技术可以充分利用太阳能等低品位热源,具有成本低、设备简单、操作容易、能耗低等优点,在海水及苦咸水淡化方面应用前景广阔。 相似文献
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Mass and heat transfer of a falling liquid film on an external screw grooved surface of perpendicular tubes were studied and correlations by similarity parameters were obtained. The mechanism for enhancement of the transfer rate by screw grooved surface was analysed. Applying Danckwerts surface renewal model to mass transfer and heat transfer, the frequencies of renewal were evaluated and compared. 相似文献
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Mass and heat transfer of a falling liquid film on an external screw grooved surface of perpendicular tubes were studied and correlations by similarity parameters were obtained. The mechanism for enhancement of the transfer rate by screw grooved surface was analysed. Applying Danckwerts surface renewal model to mass transfer and heat transfer, the frequencies of renewal were evaluated and compared. 相似文献
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ABSTRACT In a drying process of dielectric resin films coated on electric conductive substances, phenomena such as polymerization of monomers, by-products yield, shrinkage and stress generation lake place simultaneously in addition to heat and mass transfer. For the enhancement of the drying with high efficiency and high quality, it is important to understand the drying mechanism. In this paper, the characteristics of heat and mass transfer in the resin film including polycondensation reaction are presented. The apparent drying rate of polyamideimide varnish films was measured in two different heating modes of radiation and convection. The reaction rate of polycondensation was analyzed both by the thermogravimetry and the differential scanning calorimetry. The apparent drying rate began to drop remarkably when the reaction rate became significant. It implies that the diffusion of the solvent is inhibited by skinning at the surface. Applying the Vrentas/Duda free-volume diffusion model to the prediction of diffusivity, the heat and mass transfer in the resin film were analyzed theoretically with a reasonable accuracy. 相似文献
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The heat and mass transfer equations governing an adsorbent bed in an adsorption heat pump and the mass balance equation for the adsorbent particles in the adsorbent bed were solved numerically to simulate the cycle of a basic adsorption heat pump, which includes isobaric adsorption, isosteric heating, isobaric desorption, and isosteric cooling processes. The finite difference method was used to solve the set of governing equations, which are highly nonlinear and coupled. The pressures of the evaporator and condenser were 2 and 20 kPa, respectively, and the regeneration temperature of the bed was 403 K. Changes in the temperature, adsorptive pressure, and adsorbate concentration in the adsorbent bed at different steps of the cycle were determined. The basic simulated cycle is presented in a Clausius-Clapeyron diagram, which illustrates the changes in average pressure and temperature of the adsorbent bed throughout the cycle. The results of the simulation indicated that the most time-consuming processes in the adsorption heat pump cycle were isobaric adsorption and isobaric desorption. The high thermal resistance of the bed slows down heat transfer, prolonging adsorption and desorption processes. 相似文献
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热泵吸附器中传热传质过程的研究 总被引:11,自引:0,他引:11
对吸附式热泵循环系统中的传热传质进行了理论分析和实验研究,建立了吸附器中热传导方程.计算求解值与实验结果相一致,说明了吸附器中的传热速率控制了热泵循环速度.据此,对吸附器中强化传热肋片进行了模拟分析,作为吸附器优化设计的理论依据. 相似文献