整车除霜除雾影响因素研究

整车除霜除雾系统在环模验证和实际使用中出现效果差或局部除不干净问题,影响整车的驾驶安全性能。对这些问题进行仔细分析,发现整车冷却系统、空气调节系统都对其有影响,并且以空气调节系统的影响为主要因素。为此展开详细分析,并提出有效解决方案。     

Vent Location Optimization Using Map-Based Exhaustive Search in Liquid Composite Molding Processes

In liquid composite molding (LCM) processes, the resin is injected into the mold cavity, which contains preplaced reinforcement fabrics, through openings known as gates, while the displaced air leaves the mold through openings called vents. Under nominal conditions, the last points to fill are chosen as vent locations. However, due to imperfect preform cutting and placement, gaps and channels may form along the edges and curvatures in a mold, offering a path with less resistance for resin flow. The faster advance of resin through these gaps and channels, a common disturbance known as racetracking, will cause the last filled regions to vary, which complicates the vent selection process. In this study, probabilistic racetracking modeling is used to capture last-filled region distribution over the mold geometry. Success criteria for mold filling are defined in terms of dry spot tolerances, and vent fitness maps, which display potential vent locations, are created. Next, exhaustive search algorithm is coupled with vent fitness maps to determine optimal vent configurations. The map-based exhaustive search is demonstrated on three geometries and results are compared with existing combinatorial search results. The performance of the optimal vent configurations is evaluated in a virtual manufacturing environment. Sensitivity analyses are conducted to determine the influence of optimization parameters on the results.     

酸性水罐区排放气污染程度、执行标准和治理目标

以某炼油厂酸性水罐区为例,采样分析了罐区排放气组成,计算了臭气浓度和污染物排放速率,提出了罐区排放气治理前后应执行的污染物控制标准,计算了罐区排放气对标准控制指标的贡献率,给出了治理目标和应该达到的污染物去除率。     

低温推进剂输送管路热动力排气系统研究

为了实现低温推进剂的长期在轨贮存,保证推进剂从贮箱到发动机的液态供应,拟采用热动力排气系统(Thermodynamic Vent System,TVS)来实现推进剂的热管理。以单位长度液氧管路为例,阐述了热动力排气系统的原理,进行热动力排气系统孔板及TVS管路设计、在轨贮存时间计算、TVS管路排放量计算以及排放量影响因素分析。     

定子轴向通风孔对三相异步牵引电机温度场的影响

以一台大功率机车用异步牵引电机为例,根据传热理论,给出相应的求解域和数学模型。利用有限元法,计算了稳态运行的温度场,得到定子轴向通风孔不同孔距和孔径对电机温度场的影响,并对结果进行分析,得到一些有益的结论。     

Vented deflagration of a hydrogen-air mixture in a rectangular vessel with a hinged aluminum vent panel

Experiments on explosion venting of a stoichiometric hydrogen-air mixture ignited near the top vent of a 1-m³ rectangular vessel with a hinged aluminum vent panel were performed to investigate the effect of the panel area density on the pressure build-up and flame behavior. When using aluminum panels, three pressure peaks could be distinguished in the pressure-time histories. The first pressure peak, which increases with the panel area density, is the dominant one. However, the second and the third pressure peaks, with magnitudes ranging from 5 to 10 kPa, are independent of the panel area density. The use of aluminum panels weakens the external explosion because the gas mixtures were vented laterally shortly after the vent panel was opened. Panel inertia has a negligible effect on the final stage of the downward propagating flame. The maximum external flame length decreases with the increase in panel area density.     

浓缩塔放空气的工艺设计

由于变换气量及气体中硫含量的增加,导致原浓缩塔放空气中硫化氢质量浓度超标。通过增加浓缩副塔,解决原浓缩塔脱硫能力不足的问题。介绍了浓缩副塔的工艺计算和改进的工艺流程,改造后浓缩塔放空气中硫化氢质量浓度达到了设计要求。     

煤矿通风系统现状可视化仿真研究

根据某矿通风系统的应用现状,运用矿井通风可视化仿真系统Vent GIS对该矿的通风系统现状进行了可视化仿真,主要包括通风仿真系统的构建,通风网络拓扑关系的自动创建,仿真系统基础数据可视化检查,通风系统相关图形的自动生成,通风机特性可视化仿真,通风系统三维可视化仿真以及风流分配仿真,最终得出合理的风流分配方案。     

Air clearing pressure oscillation produced in a quenching tank by a prototype unit cell sparger of the APR1400

KAERI has performed a series of experiments to investigate the performance of a prototype sparger for the APR1400 in view of a dynamic load oscillation with a variation of the test conditions such as a discharged air mass, a submergence of the sparger, the valve opening time, and the pool temperature during an air clearing phase. The air mass and pool temperature are in the range of 0.8–1.5 kg and 20–90 °C, respectively. The valve opening time can be adjusted within the range of 0.6–1.8 s. The maximum positive pressure amplitude, which is observed at the bottom of the quenching tank, is increased with the maximum header pressure of the sparger. The valve opening time has a considerable effect on the maximum amplitude. As the opening time decreases, the maximum amplitude at the tank wall is increased. Air mass and pool temperature, however, have a weak effect on the maximum amplitude. Oscillation frequency is decreased with an increase of the air mass in the range of 2.5–4.5 Hz.     

响应面法优化超声波提取楮实子油工艺的研究

应用超声波提取技术,研究了楮实子油的提取工艺,在单因素的基础上,通过响应面法着重优化了提取功率、时间和料液比对楮实子油提取率的影响,经优化得出最佳提取工艺参数:提取功率285.18 W,时间62.21 min,料液比1:10 g/mL,温度45℃,提取1次,在此工艺条件下楮实子油的提取率的理论值为27.79%。并对理化性质做了简单的测定。