关于蚕茧理论烘率的探讨

本文对有关文献记载的蚕茧理论烘率公式进行了归纳和分析。并从干燥过程以及出灶后茧层和蛹体回潮率的变化趋势,探讨了理论烘率(干燥率)的计算公式。指出理论烘率可分为出灶烘率和平衡烘率;适干茧出灶时茧层的回潮率决定于干燥室内的温湿度;出灶理论烘率公式以采用 w=1.04h+1.15p(1-x)为宜。     

热风烘茧机的温湿度分布初探

本文通过对热风烘茧机内各层的温湿度测定和干茧检验,弄清温湿度分布情况,并讨论了它对干燥均匀程度,干茧质量的影响,为进一步改进烘茧机,提高烘茧质量提供参考.     

烘茧最高温度对生丝类节及色相的影响

本文探讨了烘茧最高温度分别为80°、110°、130°、145℃时,对生丝类节及色相的影响,得出以下几点结论:(1)从茧的解舒及大中类,小类成绩看,最高温度以110°—130℃为宜.(2)用最高温度145℃烘茧,则在外层茧层缫制的生丝中,发现几处较短丝段中,有很多异常的近于裂丝类的类节,受烘茧温度的影响较明显.(3)在相同煮茧、缫丝条件下,80℃低温区与145℃高温区烘茧一样,成绩并不理想.(4)对生丝颜色的影响随着烘茧最高温度的升高而变大,即白度变小,黄色系数增大,如以视觉色差指数Nc来表示,则更精确地表明视觉色差因烘茧温度的不同而异.     

鲜茧干燥新工艺的研究(二)——提高头冲温湿度加速蚕茧干燥速度

本文从蚕茧干燥机理出发,探讨了适当提高烘茧前阶段(头冲)温湿度以提高干燥速度、改善茧质的问题。试验结果表明:头冲最高温度,春茧120～135℃,秋茧110～130℃;相对湿度15％左右,有利于提高烘茧效率,改善蚕茧的工艺性能。     

蚕茧干燥后阶段温度与茧质的关系

本文探讨了烘茧第二减速干燥阶段热空气温度与茧质的关系。研究结果表明:1、茧层失水或多湿会引起较大的丝胶变性,并对茧质产生不良影响;2、第二减速干燥阶段的热空气温度以80～90℃为宜。     

鲜茧干燥新工艺的研究(Ⅲ)——头冲干燥工艺与生丝机械性能的关系

鲜茧头冲干燥工艺条件与生丝机械性能的关系经试验结果表明,在头冲阶段,热空气的相对湿度15%、流速0.5m/s、温度110～135℃时,生丝机械性能的变化均在允许的范围之内。当春、秋茧的头冲烘茧温度为120℃和125℃时,生丝的主要机械性能均比对照区110℃时好。其中头冲烘茧温度在125℃时,外、中、内茧层的丝胶在热水中的溶解速率最为接近。     

浙73-1型烘茧灶给热装置的改进方法初探

本文简介了浙73-1型灶的特点,分析了该灶的供热和耗热情况。在此基础上,提出了该灶给热装置的改进方法:(1)炉胆外表面应覆盖一层辐射率较小的板料或贴一层1～3cm厚的绝热材料;(2)头冲、二冲的用煤量应作适当的调整,头冲为35～40kg/灶,二冲为27～32kg/灶。这样有利于保全茧质,提高烘茧效率。     

过热蒸汽烘茧对茧丝品质的影响

本文研究了用过热蒸汽烘茧对茧丝品质的影响。研究结果表明,与常规的烘茧工艺相比,它是一种既节能又能改善茧质提高生丝品质的新工艺。     

不同烘茧工艺条件下蚕茧性能的检测及其探讨

本文在三种不同烘茧工艺条件,相同煮茧条件下,对三种蚕茧的动态粘弹性和解舒张力进行了检测和探讨.这对于完善烘茧理论,评定烘茧工艺具有一定的价值和意义.     

过热蒸汽烘茧对茧丝品质的影响

本研究了用过热汽烘茧对茧丝品质的影响。研究结果表明，与常规的烘茧工艺相比，它是一种既节能又能改善茧质提高生丝品质的新工艺。     

Moving behavior of pellets in a pellet shaft furnace

The downward moving behavior of pellets in a 8 m2 pellet shaft furnace with an internal vertical air channel and a drying bed was studied by means of a visualized model(1-15) and a top model(1-1).The visualized model experiment shows that the downward movement of pellets can be regarded as plug flow approximately inside the furnace except for the lower region of cooling zone due to the influence of the drained hopper.The top model experiment reveals that the pellet sizes increase along the moving direction because of the percolation phenomenon,which results in a decrease of the resistance coefficient and an increase of the gas flow rate from the furnace wall toward the furnace center.     

液冷系统中均热板气液相变的热质传输模拟

为提高电池热管理液冷系统的均温性,研究一种铝槽式均热板和直流式液冷板相结合的复合液冷系统,并建立相应的三维传热模型。采用Volume-of-fluid(VOF)多相流模型,模拟均热板槽道内丙酮工质的气液相变过程,以及与液冷流道的耦合传热过程,并将模拟结果与实验结果进行了对比,验证了模型的正确性。研究结果显示,均热板可以提高液冷系统散热过程中的均温性,加热表面的温差可以控制在2.72 K以内。通过机理分析发现,其原因与均热板内部气液工质的热质传输过程有关。在液冷系统冷却液沿程温升的影响下,均热板腔室中的丙酮气相工质在长度方向上存在定向输运现象,相变产生的蒸汽会携带热量从高温区往低温区流动,从而抑制液冷板低温冷却水对加热表面温度分布的影响,提高了均温性能。     

Experimental research of a novel vortex generator for solar absorption chiller

In this study, a novel generator for the single-effect LiBr-H₂O absorption chiller using solar energy was investigated. A dual-chamber vortex generator (DCVG) consisted of a lower chamber and an upper chamber. The hot weak LiBr-H₂O liquid entered the lower chamber tangentially through a small nozzle to create a strong vortex flow. Due to the rotating flow, the pressure was reduced toward the central portion of the lower chamber. Experiments were conducted under different solution flow rates and temperatures. The experimental results showed that the lower pressure developed in the lower chamber could reduce the saturated temperature and help the evaporation in the generator that is more heat could be utilized to generate more refrigerant vapor. When the inlet temperature was 90°C, the COP of a solar absorption chiller using the DCVG could reach 0.83, which was higher than of the conventional absorption chiller by 22%. Supported by the Opening Foundation of Beijing Municipality     

丹巴二云片岩蠕变试验研究

摘 要：丹巴水电站二云片岩为薄片状变质岩,其片理发育明显,各项异性显著。虽然关于岩石的蠕变特性研究已非常广泛深入,但关于片理结构对岩石蠕变特性影响的研究却鲜有文献涉及。通过对丹巴二云片岩进行了垂直和平行于片理面加载的蠕变试验研究,并基于试验结果,分析了片理结构对二云片岩蠕变特性的影响。发现了平行于片理面加载易使岩石呈劈裂破坏,而垂直于片理面加载易导致岩石剪切破坏。垂直于片理面加载的岩石蠕变应变远远大于平行于片理面加载的岩石蠕变应变。平行于片理方向加载的岩石蠕变破坏强度以及长期强度小于垂直于片理方向加载的岩石蠕变破坏强度以及长期强度。     

X型与Y型宽尾墩流道内水流特性研究

宽尾墩改变了流道内水力参数分布,采用RNG k-ε双方程紊流模型,定量分析了沿程水位与流速的变化。结果表明,X型宽尾墩边墙水面壅高程度在闸室段前75%范围内,约从0增大至0.2,后25%区域内增幅较大。Y型壅高程度略高于X型,两者的差别在闸室段后25%范围内呈现增加趋势。宽尾墩使得闸室段中部速度梯度减小,且Y型墩对速度梯度的影响较X型更为强烈。受逐渐扩宽的墩体尾部影响,闸室出口速度方向和大小发生改变,速度沿水深的分布极为不均,特别是水流抛射方向的显著变化与水平方向速度分量的大幅提高(与平尾墩相比)。文中提出的水面壅高程度可为工程中闸门铰链支座的布置提供参考,闸室出口速度定量分析有助于深入理解宽尾墩抛射水流在空中纵向与竖向扩散的成因。     

Hot compressive deformation behavior of an in-situ TiB whisker reinforced Ti matrix composite

An in-situ TiB whisker reinforced Ti matrix (TiBw/Ti) composite is fabricated by powder metallurgy technique followed by hot extrusion. Hot compressive deformation behavior of the composite, in which the TiB whiskers were oriented along the extruded direction, is investigated. The results indicate that the hot compressive resistance of the TiBw/Ti composite is higher than that of the unreinforeed Ti, and hot compressive resistance of the composite in the direction parallel to the whisker orientation is higher than that in the direction perpendicular to the whisker orientation. The hot compressive resistance of the composite increases with increasing strain rate and decreasing temperature. With increasing test temperature, the rate of the decrement of the compressive flow stress of the composite is higher than that of the unreinforced Ti. With increasing amount of compressive deformation, more and more TiB whiskers rotate and break during deformation. The rotation of the whiskers is easier at higher temperature, while, at lower temperature it becomes more difficult and whisker breakage becomes much more serious.     

用格子Boltzmann方法模拟圆柱绕流的振荡边界层

提出了一种用于模拟圆柱绕流的振荡边界层流动的新方法——旋转系统平均法。该系综由一些相同的系统组成,每个系统除使用不同的网格外,具有相同的流动。经模拟圆柱绕流的振荡边界层发现,流体质点的流动具有平行于振荡方向离开圆柱、竖直于振荡方向流向圆柱的特点,同时也发现在紧邻圆柱出现的被称为二次流的4个涡旋流动现象。数值模拟结果符合经典的理论结果。该方法也可用于其他圆柱绕流问题。     

用格子Bohzmann方法模拟圆柱绕流的振荡边界层

提出了一种用于模拟圆柱绕流的振荡边界层流动的新方法——旋转系统平均法。该系综由一些相同的系统组成，每个系统除使用不同的网格外，具有相同的流动。经模拟圆柱绕流的振荡边界层发现，流体质点的流动具有平行于振荡方向离开圆柱、竖直于振荡方向流向圆柱的特点，同时也发现在紧邻圆柱出现的被称为二次流的4个涡旋流动现象。数值模拟结果符合经典的理论结果。该方法也可用于其他圆柱绕流问题。     

Study of fissured-rock seepage flow with isotope tracer method in single borehole

A systematic summary is presented describing the application of isotope tracer method in detecting seepage flow in a single borehole. In a single borehole, many hydraulic coefficients, such as flow velocity, direction of flow, vertical flow etc., can be obtained by using isotope tracer method. There are three conditions if a fissure intersects a borehole: vertical, parallel and tilt. According to each different condition, the formulation of flow velocity deduced by isotope dilution method is different. At the same time, well theory of blended borehole about fissure groups including single fissure group and multi-fissure groups, has also been discussed.     

Study of fissured-rock seepage flow with isotope tracer method in single borehole

A systematic summary is presented describing the application of isotope tracer method in detecting seepage flow in a single borehole. In a single borehole, many hydraulic coefficients, such as flow velocity, direction of flow, vertical flow etc., Can be obtained by using isotope tracer method. There are three conditions if a fissure intersects a borehole: vertical, parallel and tilt. According to each different condition, the formulation of flow velocity deduced by isotope dilution method is different. At the same time, well theory of blended borehole about fissure groups including single fissure group and multi-fissure groups, has also been discussed.