铝熔体旋转喷吹净化动态水模拟试验研究

通过动态水模拟试验考察了喷头转速、气体流量和喷头浸入液体深度三个因素与气泡尺寸的关系,利用二次回归正交试验方法设计试验过程。试验结果表明,可以观察到气泡床的偏移,在特定的容积内喷头转速对气泡尺寸的影响最大,其次是气体流量,而喷头浸入深度对气泡尺寸影响较小。在现有的模拟试验条件下,当喷头转速215 r/min、气体流量2.94 m3/h、喷头浸入深度551 mm时,可以获得最理想的气泡尺寸。用相应设备处理铝熔体时,对铝熔体的含氢量进行测定。结果表明,在适宜的结构空间内,大叶轮、低转速的合理工艺组合可以获得较理想的除气效果。

循环水动态模拟装置的精确温度控制

针对具有大容量滞后环节的循环水动态模拟装置入口水温控制对象 ,研究了一种新的控制方法及控制算法 。

通过微机测控实现水稳剂的在线评选

水稳剂的评价和筛选是工业水处理的重要环节,循环水动态模拟试验装置是专用的水稳剂评选设备,通过在线获取污垢热阻的变化趋势,能够对水质稳定配方效果及操作工艺条件进行综合评价;在介绍了该装置的工作原理基础上,重点介绍了为该装置开发的微机测控系统,内容包括:微机测控系统的硬件组成框架、软件结构、功能及开发思想。实践证明该系统操作简单,性能可靠,能满足长周期、高性能的测控要求,用户可直接根据污垢热阻的变化趋势进行水稳剂的筛选。

对水平井水淹动态产生重要影响的因素分析与水淹动态模拟

水平井技术在油田的开发上已经得到广泛的运用,在新老油田的高效开发上都做出了极大的贡献。通过长期的开发实践,我国形成了一套完备的水平井开发技术。但是因为水平井的不同,所以它在水淹动态的特征上有着明显的差异,水平井水淹动态的产生,有着很多因素,如夹层以及水平井段长度等。

铝熔体在线除气净化机制研究

阐述液态铝液在线除气的物理化学原理,分析国内外铝液在线除气的研究状况和存在的不足。创新性地采用同实际铝液流量相当的动态水模拟试验进行研究,发现了动态两相流运动中存在合泡和短流现象。并提出有效的解决措施。同时发明了多项专利技术,发挥产学研密切配合的优势,研发出节能减排的在线除气工艺技术和装备。

Dynamic Simulation and Analysis of Industrial Purified Terephthalic Acid Solvent Dehydration Process

Dynamic model for dehydration process of industrial purified terephthalic acid solvent is investigated to understand and characterize the process.A temperature differential expression is presented,which ensures the equation to convergence and short computation time.The model is used to study the dynamic behavior of an azeotropic distillation column separating acetic acid and water using n-butyl acetate as the entrainer.Responses of the column to feed flow and aqueous reflux flow are simulated.The movement of temperature front is also simulated.The comparison between simulation and industrial values shows that the model and algorithm are effective.On the basis of simulation and analysis,control strategy,online optimization and so on can be implemented effectively in dehydration process of purified terephthalic acid solvent.

Experimental investigation on dynamic response of chamber to simulate deepwater explosive

Experimental investigation was conducted for the dynamic response of a real spherical explosive chamber that can simulate 200 m deepwater explosive loaded 10 g TNT equivalent.The vibration characteristics and dynamic strength of the chamber were analyzed by measuring the strain profiles of six characteristic points on the chamber.The research results revealed the rule of the dynamic response of the chamber on different explosive loads and static pressures.It provides references for the design and development of the chamber to simulate deepwater explosion.

Numerical and Experimental Study on Dynamic Performance of Heat Pump Water Heater with Electronic Expansion Valve

A series of experiments on the dynamic performance of the HPWH （heat pump water heater） unit with EXV （electronic expansion valve） under different environmental conditions were conducted. The dynamic heating capacity and COP （coefficient of performance） of the HPWH unit under different EXV openings were measured. The effects of the EXV opening on the performance of the HPWH unit were analyzed. Meanwhile, the dynamic performance of the HPWH with EXV was simulated and the results were compared with the experimental one. The experimental results indicate that during heating process, the COP increases firstly and then decreases for a fixed EXV opening, which is in good agreement with the numerical result. For different EXV openings, the COP and heating capacity of the system using larger EXV opening are superior to those using the smaller one in the initial heating stage. While in the late stage, the performance of system using smaller EXV opening is better. It is found that the system performance is improved significantly by changing the EXV opening in the different heating period and the average COP of the HPWH system is increased by 7.6%.

A distributed scheme developed for eco-hydrological modeling in the upper Heihe River

Modeling the hydrological processes at catchment scale requires a flexible distributed scheme to represent the catchment to- pography, river network and vegetation pattern. This study has developed a distributed scheme for eco-hydrological simulation in the upper Heihe River. Based on a 1 km x 1 km grid system, the study catchment is divided into 461 sub-catchments, whose main streams form the streamflow pathway. Furthermore, a 1 km grid is represented by a number of topographically similar ＂hillslope-valley＂ systems, and the hillslope is the basic unit of the eco-hydrological simulation. This model is tested with a simplified hydrological simulation focusing on soil-water dynamics and streamflow routing. Based on a 12-year simulation from 2001 to 2012, it is found that variability in hydrological behavior is closely associated with climatic and landscape condi- tions especially vegetation types. The subsurface and groundwater flows dominate the total river runoff. This implies that the soil freezing and thawing process would significantly influence the runoff generation in the upper Heihe basin. Furthermore, the runoff components and water balance characteristics vary among different vegetation types, showing the importance of coupling the vegetation pattern into catchment hydrological simulation. This paper also discusses the model improvement to be done in future study.

Numerical Simulation of Soil Water Dynamics in a Drip Irrigated Cotton Field Under Plastic Mulch

Drip irrigation under plastic mulch has been widely applied in arid Northwest China as a water-saving irrigation technology. A comprehensive knowledge of the distribution and movement of soil water in root zone is essential for the design and management of irrigation regimes. Simulation models have been proved to be efficient methods for this purpose. In this study, the numerical model Hydrus-2D was used to simulate the temporal variations of soil water content in a drip irrigated cotton field under mulching. A concept of partitioning coefficient, calibrated to be 0.07, was introduced to describe the effect of plastic mulch on prevention of evaporation. The soil hydraulic parameters were optimized by inverse solution using the field data. At the optimized conditions, the model was used to predict soil water content for four field treatments. The agreements between the predictions and observations were evaluated using coefficient of determination （R2） and root mean square error （RMSE）. The results suggested that the model fairly reproduced the variations in soil water content at all locations in four treatments, with R2 ranging from 0.582 to 0.826 and RMSE from 0.029 to 0.050 cm3 cm-3, indicating that the simulations agreed well with the observations.

Uncertainty and Sensitivity Analyses for Modeling Long-Term Soil Organic Carbon Dynamics of Paddy Soils Under Different Climate-Soil-Management Combinations

Reporting modeling results with uncertainty information can benefit decision making by decreasing the extent that variability exerts a disproportionate influence on the options selected. For making decisions with more confidence, the uncertainty interval should be as narrow as possible. Here, the soil organic carbon （SOC） dynamics of the major paddy soil subgroup from 4 different paddy field regions of China （located in 4 counties under different climate-soil-management combinations） were modeled using the DeNitrification- DeComposition （DNDC） model for the period from 1980 to 2008. Uncertainty intervals associated with the SOC dynamics for these 4 subgroups were estimated by a long-term global sensitivity and uncertainty analysis （i. e., the Sobolt method）, and their sensitivities to 7 influential factors were quantified using the total effect sensitivity index. The results, modeled with high confidence, indicated that in the past 29 years, the studied paddy soils in Xinxing, Yixing, and Zhongjiang counties were carbon （C） sinks, while the paddy soil in Helong County was a C source. The 3 C sinks sequestered 12.2 （5.4, 19.6）, 17.1 （8.9, 25.0）, and 16.9 （-1.2, 33.6） t C ha-1 （values in the parentheses are the 5th and 95th percentiles, respectively）. Conversely, the C source had a loss of -5.4 （-14.2, 0.06） t C ha-1 in the past 29 years. The 7 factors, which changed with the climate-soil-management context, exhibited variable influences on modeled SOC. Measures with potential to conserve or sequestrate more C into paddy soils, such as incorporating more crop residues into soils and reducing chemical fertilizer application rates, were recommended for specific soils based on the sensitivity analysis results.