烟道流量计量标准装置

为了解决我国烟道流量计的量值溯源问题,中国计量科学研究院建立了烟道流量计量标准装置。装置使用可溯源至标准转盘的激光多普勒测速仪作为原级标准器,采用激光多普勒流速剖面扫描和超声流量计波动修正的方式测量标准流量,经校准的8声道超声流量计为工作级标准表,具备了908~104840m3/h的测量能力,扩展不确定度为0.62%(k=2),可对最大口径为1m的流量计进行校准。装置下游测试段包括圆形管段和矩形管段,能够开展烟道流量计测量性能的研究。     

Systematic exploration of the applicability of the idiomatic vapor balance rule to distillation column consolidation

For N-component distillation(N ≥ 3), consolidation between different column sections is an inevitable manipulation when synthesizing complex distillation configurations. In the consolidation, the idiomatic vapor balance(IVB) rule, in which the larger vapor flowrate in the two columns before consolidation will be chosen as the balanced vapor flowrate at the consolidation point, has been widely used. However, the applicability of the IVB rule has not been verified, which is of essential importance to the accuracy of the distillation configuration synthesis.In the present study, the applicability of the IVB rule to distillation column consolidation was systematically explored by rigorous method for the first time. First, the separation of ideal and non-ideal three-component mixtures with variable compositions was studied, and the optimized configurations before and after consolidation were determined by a rigorous method. The results indicated that for the separation of an ideal mixture, the IVB rule was applicable for the whole composition range, while for the separation of a non-ideal mixture, the IVB rule was only applicable for very limited composition range. Finally, two cases of synthesizing distillation configurations for the separation of non-ideal mixtures were studied to verify the remarkable deviations the IVB rule may cause. The results indicated that the applicability of the shortcut method using the IVB rule to the distillation configuration synthesis depended on the composition of the non-ideal mixture, and a remarkable error might result and the truly optimal configuration might be missed if the IVB rule is applied to a non-ideal mixture.     

Pitometry as a validation tool for water flow measurement in large diameter pipelines

Accurate measurement of water flow rates in large diameter pipelines is a challenge for water companies that need to produce, transport and distribute increasing quantities of water. To a large extent, this challenge results from the impossibility of recalibration of the flow meters within the periodicity established in the metrological regulations since the removal of a large size flow meter from its site of operation in the field and its transport to a calibration laboratory is in most cases technically and economically impracticable. Because of this scenario, this paper presents the pitometry technique as an interesting alternative to solve problems related to the validation of water flow measurements performed by flow measurement systems installed in large diameter conduits. The technique is based on the determination of the water flow rate by mapping the velocity profile of the water flow inside the pipe by means of Cole type Pitot tubes. The water flow rate is determined in a cross section of the pipe located near and in series to the flowmeter to be evaluated. Based on the results obtained in a great number of water flow measurements already performed by applying the pitometry technique in large diameter pipelines in the field, it is possible to conclude that this methodology is perfectly applicable in the validation of the performance of flow meters installed in these conduits solving satisfactorily the issues related to its operation.     

Effect of ultrasound on bubble breakup within the mixing chamber of an effervescent atomizer

Gas bubbles introduced into a liquid in the mixing chamber help to break up the liquid into fine droplets on being expanded to the ambient pressure. The passage of gas bubbles through the orifice of the nozzle requires that the size of the bubbles be much smaller than the diameter of the orifice. In the present work, the effectiveness of 20 kHz ultrasound to increase number density of fine bubbles within the mixing chamber of an effervescent atomizer by breaking up bubbles introduced in it by an aerator was investigated. Bubbles of initial size in the range of 5-10 mm were shown to get disintegrated into clusters of micron and sub-micron sized bubbles. A fine spray was produced in the presence of ultrasound at a gas-to-liquid mass flowrate ratio (GLR) of 0.063%. The half-cone angle of spray was in the range of 6-10°, which compares favorably with conventional atomizers. The experimental findings of bubble breakup were theoretically modeled by the Rayleigh-Plesset equation. The results of the model indicate that bubbles having initial radius less than 3 mm undergo growth and subsequent disintegration at 20 kHz for the given acoustic pressure of 0.3 MPa.     

反应溅射制备MoO3薄膜及其光学和电致变色性能研究

本文采用磁控溅射方法,通过金属钼靶材在Ar+O2气氛中反应溅射制备了氧化钼薄膜.在制备样品过程中改变反应气氛O2的流量,保持其它参数不变,得到不同的氧化钼薄膜.采用X射线衍射(XRD)和扫描电子显微镜(SEM)方法对MoO3薄膜样品结构进行表征.XRD测试结果表明MoO3薄膜样品均为非晶结构.MoO3薄膜样品的光学性能和电致变色性能采用分光光度计进行测试研究.研究结果表明,当反应气氛O2/Ar流量比例为1:5时,所制备的样品具有较高的可见光透射率,可见光平均透射率为90%,并且电致变色性能较好,调色范围达到了66.94%.     

一种井控节流阀防刺短节的特性分析

节流阀是钻井井控管汇中的关键设备,现场应用中常因阀座、阀心的冲蚀磨损而失效,给井控带来了很大的安全隐患。防刺短节就是针对此问题而设计的。采用三维流场分析的方法,对带和不带防刺短节的楔形节流阀的流量特性进行对比分析。分析结果表明,防刺短节可以减小壁面上的流体速度进而减小壁面的冲蚀;防刺短节的节流效果不明显,其对节流阀的压力控制没有明显变化;加防刺短节后,流线复杂,流场漩涡增多,可能会产生振动和噪声。最后提出用普通碳钢材料来制造短节合金头以降低成本。     

转炉底吹KGC技术的引进与应用

主要介绍我国首次引进的转炉底吹气体控制ＫＧＣ技术的工艺要求，底吹气体流量、气体种类的控制功能，系统构成以及在宝钢三期二炼钢４＃、５＃转炉上的应用情况。     

尿素装置高压氨泵入口流量低联锁改造

尿素装置高压氨泵原来的入口流量低联锁能够满足在吸入流量低的时候打开回流阀确保泵的安全,但是无法满足泵启动过程等特殊情况下的操作需求,论述如何从软件、硬件两个方面进行联锁改造。     

虹吸雨水排水系统虹吸形成最小流量曲线的数字化

虹吸雨水排水系统对管道设计有一定要求．德国工程师协会依据大量原型试验的数据,绘制出了虹吸雨水排水系统虹吸形成的最小流量曲线,但在查阅曲线往往会遇到一些困难,特别是在涉及计算机计算时很不方便．现介绍一种曲线数字化方法,对该标准中曲线进行数字化处理,并拟合出相应的方程．     

大流量承压水井成井工艺探讨

大流量承压水井从钻进到成井如何做到保证不自流，又能缩短成井时间。