喷射成形棒坯中沉积距离和回缩速度的选择

利用计算机数值模拟技术采用平均质量流率法建立了喷射成形空间质量流率分布和棒坯生长模型，通过讨论喷射成形空间质量流率分布得出沉积器的最佳位置hm和最佳回缩速度vo并计算了不同喷射参数对沉积坯端面形貌的影响。     

用限制型低压喷嘴制备细金属粉末

本文叙述了关于用低压限制型空气雾化器制备锡粉和铅粉的研究。测量了与雾化气体压力和末端位置有关的地液管末端的压力参数。讨论了对粉末性能有影响的工艺参数，如：气体压力、熔体温度、末端位置和气体对金属流的流率。使用的空气压力在０．２２至０．７１ＭＰａ时，可获得平均直径在１３至２２μｍ之间的粉末，粒度分布符合对数正态分布图。     

双层微孔金属气体分离膜的参数搭配关系

渗透性和粘流率是气体扩散分离膜的两个主要特性。根据其定义，推导出用于混合气体（H2-N2，H2－CO2和H2－CH4）分离的双层微孔金属膜的多数搭配关系式，并分析了骨架层渗透位变化对双层膜分离性能的影响。在此基础上，提出分离膜的理想结构。     

喷射成形雾化器结构对流场的影响

采用美国商用流体力学软件(CFD)模拟了喷射成形雾化腔内气体流动状态,分析了四种不同雾化器喷管结构的流场特点。结果表明:在一定的压力和尺寸条件下,汇聚喷管结构的高速射流区域比汇聚发散结构喷管大,对气体加速作用较好;导流管末端气流速度影响抽吸气体流率,从而影响引流效果;和汇聚发散结构相比汇聚结构喷管更适合用于双层雾化器引流结构。     

铝合金低压气雾化技术研究

根据气体动力学原理和雾化机制，在以自行设计的限制式雾化喷嘴为核心的雾化装置上，研究了当雾化介质压力较低时工艺参数对铝合金雾化效果的影响，结果表明，当雾化介质为氮气，压力为１．０ＭＰａ，合金液温度为７８０℃，液流率主０．８ｋｇ／ｍｉｎ时，可获得符合喷射沉积技术要求的雾化效果。     

新型侧搅拌流化床气-固流化质量的模拟

在流态化炼铁的过程中,由于气-固分布不均匀,导致节涌、沟流、气体利用率低、粘结失流等现象,甚至出现死床的状况.本实验建立新型侧搅拌流化床反应器的物理模型,研究了搅拌方式、空气体积流率、搅拌器转速、搅拌器倾斜角度四个因素对流化床内颗粒与气泡运动行为及压强变化规律的影响.结果表明:侧搅拌流化床的气-固流化质量优于垂直搅拌流...     

城市快速路设计的几个问题：北环大道设计心得与思考

通过对北环大道交通流量的分析，推荐采用美国的高峰小时流率交通量的计算方法，及各级服务水平的道路通行流率公式，此外，对辅路设置、立体交叉设计等技术细节也做了详细的阐述。     

罩式炉内保护气体流场测试与分析

通过对罩式炉内保护气体的流动静压和动动压的测量，计算出了炉内保护气体的流场分布，分析了引起罩式炉内保护气体流态不稳定、流场分布不均匀的原因，提出了改善炉内保护气体流动状态和流场分布的具体措施，为改善冷轧钢卷罩式炉退火质量提供参考。     

炉缸异常侵蚀条件下鼓风参数分布的模拟研究

为分析高炉炉缸异常侵蚀条件下调整风口直径后的鼓风参数分布，利用数值模拟方法研究了热风管道及各风口的压力、速度、体积流率及鼓风动能分布。计算结果表明，相同风口直径分布条件下，鼓风参数并不完全相同，随着热风向三岔口对向流动，体积流率和鼓风动能整体逐渐增大；对炉缸异常侵蚀的风口，缩小风口直径，风速增加，体积流率降低，鼓风动能降低，符合保护炉缸、抑制侵蚀的目的。     

转炉煤气驱动开式燃气轮机CCHP装置FTT建模与优化

炼钢转炉余能余热主要包括转炉烟气的显热和转炉煤气的潜热以及转炉渣的显热,合理回收利用转炉余能余热是实现转炉负能炼钢的关键。建立了转炉煤气驱动的开式燃气轮机热电冷联产(CCHP)装置有限时间热力学(FTT)模型。以装置总可用能率和第一定律效率为目标,在无煤气质量流率和装置尺寸约束下,优化了压气机进口相对压降和压比,得到了最大总可用能率和相应的煤气质量流率;在煤气质量流率和装置尺寸约束下,优化了压气机进口相对压降,得到了最优效率,同时联产装置各部件的面积分配也得到了优化。分析了煤气显热利用、放散率、循环总温比、发生器工质温度和供热温度等参数对装置最优性能的影响。     

气流出口截面恒定的雾化器设计

利用流体力学理论,对雾化器产生的气流出口流速及质量流率进行了分析.当雾化器出口截面恒定时,建立了气流出口流速呈极大值所需的雾化压力的数学表达式;导出了在雾化气流量恒定条件下,气流出口流速呈极大值时出口截面积与雾化器腔体截面积的函数关系式.     

环孔雾化喷嘴设计参数的研究

根据对雾化气流流动的理论分析及环孔雾化喷嘴设计参数的研究,提出了环孔雾化喷嘴设计参数的定性解析和定量描述;导出了在环孔雾化喷嘴出口处雾化气体流速及质量流量取得极大值时,雾化喷嘴气流出口截面积与空腔截面积及雾化压力的解析表达式;建立了雾化气体流速与环孔雾化喷嘴节圆直径、环孔直径及喷射顶角的函数关系式;探讨了保障环孔雾化喷...     

Convective Mass Transfer onto Multiple Gas Bubbles

An analysis has been performed on the fluid flow and convective mass transfer in a system consisting of many gas bubbles. Both interference effects of neighboring bubbles and the influence of the circulation induced inside the bubbles on the flow field and the mass transfer rate were taken into account in the analysis. Analytical solutions were obtained for the mass transfer rate. The results indicate that both the packing density and the viscosity ratio of fluid spheres and surrounding fluid have significant effects on the flow field and the mass transfer rate. It was found that the mass transfer rate in a system of bubbles becomes much higher than that for a system of solid spheres. Based on the analytical results, discussions are provided concerning the mass transfer onto gas bubbles from liquid flow.     

Model study on mixing and mass transfer in ferroalloy refining processes

An experimental study has been performed to investigate the bath mixing intensity induced by a high-strength submerged gas injection in a bottom blown air-stirred one-seventh water model of Creusot-Loire Uddeholm (CLU) reactor using three different tuyere configurations. Experimental results have been discussed in terms of the mass transfer rate and mixing time. The air flow rates varied from 0.00599 to 0.01465 m³/s. The mixing time was determined at various gas flow rates, bath heights, and nozzle orientations, both in the presence and absence of a second phase. The mixing time was found to decrease with increasing gas flow rate and decreasing bath height. The influence of bath mixing intensity on mass transfer between metal (water) and slag (paraffin) was studied by measuring the transfer of benzoic acid from the gas-stirred water bath to paraffin as a function of the gas injection parameters. The bath mixing intensity was characterized by the value of the mass transfer rate constant. The rate constant of mass transfer between the metal and slag was found to increase with increasing gas injection rate and decreasing bath height.     

高炉喷吹煤粉总管质量流量的在线连续测量

提出了一种对高炉喷吹煤粉总管流量进行在线连续测量的新方法。通过电容传感器对煤粉浓度的测量,可以求出喷吹过程的固气比,结合煤、气混合之前所测得的载气流量,便可测出煤粉的质量流量。实测结果显示,测量误差小于５ ％ 。     

120tLF炉钢包底吹工艺优化

针对天钢120LF精炼炉的实际情况并结合水模试验数据,对不同钢包底吹流量的钢液混匀时间、夹杂物去除效果、钢包卷渣的临界流量等进行了研究,制定了钢包底吹流量参数。最终通过引进新的钢包底吹设备使得工艺优化得以顺利完成。取得了良好的效果。     

Cold Simulation of Oxygen Transfer Rate in BOF

 By measuring the mass transfer coefficient of between water and oil, the oxygen transfer rate of bath in the BOF smelting process is researched, and the influence of top and bottom blowing gas flow rate on the mechanism of mass transfer between metal and slag is discussed. The results show that when the bottom blowing gas flow rate increases on the conditions of top blowing, the mass transfer rate evidently increases, and the influence ratio of top blowing on the mass transfer is 10 percent of bottom blowing; The relation among top gas flow rate, bottom gas flow rate and lance height are established by the stirring power density. The equation between the mass transfer coefficient between metal and slag is formed, which furnishes reference for optimizing process parameters of BOF. The relation between the emulsification ratio between water and oil and the bottom blowing gas flow rate on the condition of top and bottom blowing is obtained. The result shows that with the increase of the bottom blowing gas flow rate the emulsification ratio increases in linearity, which increases the mass transfer rate of benzoic acid between water and oil.     

沼气提纯过程中二乙醇胺溶液吸收二氧化碳的影响因素

采用交互作用正交试验设计,系统研究了进液流量、进气流量、CO₂体积分数、进液温度及其交互作用对填料塔中二乙醇胺溶液吸收CO₂的转化率η和气相总体积传质系数K_Ga_e的影响.经过直观分析和方差分析,评价了各参数对η和K_Ga_e影响的显著程度.实验发现进液流率、进气流率、CO₂体积分数、进液温度,以及CO₂体积分数与进气流率、进液温度与进液流率、进液温度与进气流率的交互作用对η影响显著;进液流率、进气流率、CO₂体积分数、进液温度、CO₂体积分数与进气流率的交互作用以及进液温度与进气流率的交互作用对K_Ga_e影响显著;进气流率增加,η降低而K_Ga_e增加;进液流率增加,η和K_Ga_e均增加;进气CO₂体积分数增加,η和K_Ga_e均降低;进液温度升高,η和K_Ga_e均呈先增加后减小趋势.