共查询到17条相似文献,搜索用时 62 毫秒
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本文简述了前苏联20世纪40年代以来,对于蒸汽的凝结和真空冷冻干燥技术及设备的研究与应用情况,还详细介绍了几种升华干燥设备及其计算方法和实例。 相似文献
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本文简述了前苏联20世纪40年代以来,对于蒸汽的凝结和真空冷冻干燥技术及设备的研究与应用情况,还详细介绍了几种升华干燥设备及其计算方法和实例。 相似文献
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针对乙烯车间蒸汽平衡系统运行现状,采取提高裂解气压缩机和丙烯压缩机的抽汽量、降低乙烯压缩机的抽汽量、提高裂解炉S100产汽、减少外排水增加稀释蒸汽(DS)产量等措施,提高了装置自产蒸汽和DS的产量,降低了压缩机、精馏塔等设备的蒸汽使用量,减少了各等级蒸汽的界外补入。 相似文献
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通过对蒸汽动力装置进行能平测试,并对测试数据进行能量平衡分析和Yong平衡分析,给出了测量结果及改进意见。 相似文献
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R22饱和蒸汽在C-S水平管外凝结换热的实验研究 总被引:1,自引:0,他引:1
以R22为工质在套管式冷凝器中对C-S水平管在饱和蒸汽状态下冷凝传热的性能进行实验研究,得出凝结换热系数与表面张力及蒸汽流速之间的关系,并拟合出其实验关系式。 相似文献
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非平衡式压缩机并联技术 总被引:1,自引:1,他引:1
压缩机并联技术的关键在于解决回油分配问题。油气平衡式并联技术平均分配回油,并强调气压和油位的平衡。非平衡并联机技术建立了压缩机回气压力等级,并按等级高低分配回油。 相似文献
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地质聚合物(Geopolymer)是一类由活性铝硅酸盐矿物在碱激发作用下形成的非传统胶凝材料,具有高强、耐久、绿色环保等特点.但地质聚合物原材料和碱性激发剂的多样性使其水化机理异常复杂,凝结硬化性质不确定性增加,且受环境温度变化影响大.因原材料及制备工艺不同,地质聚合物凝结硬化特性可能走向两个极端:(1)凝结硬化过快,难以施工;(2)长时间不凝结硬化,早期强度发展慢.通过合理有效的方法将其凝结时间调控至适合范围,是实际工程应用中亟需解决的关键问题.本文分别阐述了高钙、低钙和无钙体系下地质聚合物的凝结硬化机理,详细分析了铝硅酸盐原料细度、活性及CaO含量,激发剂的类型、掺量以及环境温度等因素对地质聚合物凝结时间的影响,概括总结了调节地质聚合物凝结时间的技术方法,并分析了其作用机理,以期为地质聚合物的应用研究提供技术支持. 相似文献
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《低温学》2016
The difficulty of data measurement in cryogenic environments and the complicated mechanism of nucleation process have restricted the design of wet type turbo-expander for cryogenic liquid plants. In this paper, equilibrium and non-equilibrium models are used to model the spontaneous condensation flow in a cryogenic turbo-expander along the main stream passage including nozzle, impeller and diffuser. The comparison shows a distinct difference of the predicted wetness fraction distribution along the streamline between the equilibrium model and the non-equilibrium model. In non-equilibrium model, the distributions of supercooling and nucleation rate along the length of turbo-expander are given for the analysis of flow characteristics. The comparison of outlet wetness fraction with the experimental data is also provided for verification and discussion. Both the effects of the rotation on nucleation and the effects of the nucleation on flow along suction side of the impeller are investigated. 相似文献
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In order to reduce the non-equilibrium condensation occurring in ejector primary nozzle, wet steam model was adopted to investigate the relationship between steam superheated level and non-equilibrium condensation within ejector primary nozzle. Simulation data of axial static pressure along primary nozzles were validated with experimental data reported in literature. The non-equilibrium condensation process from homogeneous nucleation to droplet growth stage and the resulting products were carefully studied. Moreover, six inlet superheated levels from 5 K to 30 K with the increment of 5 K were compared, and simulation results showed that the increase of superheated level from 5 K to 30 K causes 40.22% delay in the location and 43.92% reduction in the intensity of the condensation shock. Furthermore, there is about 24.30% liquid mass fraction decrease when the superheated level raises to 30 K and total entropy generation increases slowly with the increase of superheated level. 相似文献
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A. J. White 《International journal for numerical methods in engineering》2003,57(6):819-834
Spontaneous nucleation of water droplets in moist air or steam may result in droplet spectra which are complex in shape and which span a broad range of sizes. This is particularly true if the flow is transonic or supersonic with shock waves present, or if an already droplet‐laden flow re‐expands to give secondary or tertiary nucleations. Computation of such flows requires careful modelling of the size distributions if two‐phase behaviour is to be accurately predicted. In this paper, three methods are presented for treating size distributions and growth of the liquid phase in condensing steam: a mixed Eulerian–Lagrangian method, a fully Eulerian method, and a method based on moments of the droplet spectra. These are compared by computing condensing flow within a one‐dimensional supersonic nozzle under conditions that yield very different types of size spectra. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
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微肋管结构对管内冷凝换热影响的研究 总被引:1,自引:0,他引:1
相对于光管,微肋管的结构参数相对较多,这些结构参数的变化会不同程度地影响微肋管的换热能力,国内外的很多学者进行了研究,但结论相差较大,甚至完全相反。因此本文对这些研究成果进行一定的分析和回顾,希望能为铜管生产厂商以及空调设计工程师提供相关的参考,也为今后的研究工作提供一定的借鉴。 相似文献