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The mathematical expressions for exergy and the exergy analysis of the freezing stage of the freeze drying process are presented. The exergy analysis indicates that very substantial reductions in the magnitudes of the total exergy loss and of the exergy input due to the heat that must be removed during the freezing stage, can be obtained when the freezing stage is operated through the use of a rational distribution in the magnitude of the temperature of the cooling source. The rational distribution in the magnitude of the temperature of the cooling source should provide significant savings in the utilization of energy during the freezing stage of the freeze drying process as well as satisfactory freezing rates that form ice crystals that are continuous and highly connected and their shape and size are such that the pores of the porous matrix of the dried layer generated by sublimation during the primary drying stage, have a pore size distribution, pore shape, and pore connectivity that are appropriate to allow high rates for mass and heat transfer during the primary and secondary drying stages of the lyophilization process. 相似文献
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Toshiyuki Tanaka Kazuyuki Shimizu Masakazu Matsubara 《Chemical Engineering Communications》1985,36(1):223-232
The exergy analysis is done for the conventional distillation, the VR (Vapor Recompression) distillation, and the SRV (Secondary Reflux and Vaporization) distillation with the aid of computer simulation. It is shown that the careful use of thermodynamic diagrams helps us for the exergy analysis. 相似文献
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低温甲醇洗过程(火用)分析 总被引:1,自引:0,他引:1
根据某化肥厂合成氨系统中的低温甲醇洗工段的工艺,建立了(火用)分析模型.对甲醇洗系统进行了(火用)分析,并且与能量分析进行了比较,分析系统用能的薄弱之处,提出相应的改进措施. 相似文献
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以热力学第一、第二定律为基础的热平衡分析法和火用平衡分析法相结合,对热管式蒸汽发生器进行了火用分析,给出了热管式蒸发器中各部分的火用损失情况,指出其合理的布置方式 相似文献
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E. E. Pressler 《Journal of the American Ceramic Society》1930,13(11):850-855
A method of feldspar analysis is described by which all the major oxides are determined on one sample, and a practical routine procedure is developed on the basis of this method. 相似文献
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通过计算机模拟,对溴化锂第二类吸收式热泵热力过程和热泵系统各部件进行了详细计算,提出了循环倍数、工作液浓溶液浓度、蒸发温度、冷却温度对Yong效率的影响程度。指出了Yong损失的分布,计算了Yong损系数和Yong效率。 相似文献
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通过对高压聚乙烯反应系统进行Yong计算与分析,结果表明,由传热不可逆造成的内部Yong损为主要的Yong损。一、二、三段反应器的内部Yong损各占其总Yong损的97.78%、98.87%、85.44%。并提出了相应的节能措施和优化方案。 相似文献
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为了评价热管换热器的经济性能,本文对热管换热器进行了效率分析,给出了气气型热管换热器的效率随热、冷流体的流动状况,与热管的长度、直径等几何尺寸的变化曲线,为优化设计热管换热器提供了理论依据。 相似文献
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An exergy balance equation which relates to heat and mass transfer on distillation stages was derived from the theory of non-equilibrium thermodynamics. This equation was used to analyze an ethylene distillation column, and the result checked satisfactorily with that of equilibrium thermodynamic exergy analysis.In a multiphase discontinuous system, each phase may be considered as a subsystem, and all subsystems are separated by interfaces. With appropriate hypotheses, the equation of exergy loss relating to energy and mass transfer through interfaces may be expressed as follows:D=T_o[J_q·Δ(1/T)-sum from k to n J_k·Δ(μ_k/T)] Thus, profound insight into distillation process could be gained to provide ideas for further improvement of the distillation scheme. 相似文献
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从宏观检查和微观检测分析了合成氨装置变换单元减温器开裂失效的原因,采取必要的解决措施,保证了减温器安全运行。 相似文献
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通过与设计参数对比,对建峰化肥厂布朗工艺合成氨装置能耗高的原因进行了分析,着重剖析了蒸汽、燃烧气消耗高于设计值的原因,并提出了解决办法。 相似文献