Experimental modelling of a pilot lignocellulosic pellets stove plant

Small-scale stoves, producing heat and hot water, are suited for domestic purposes. In order to optimise their efficiency when using lignocellulosic pellets, an important task is to do research on their real performance. The general behaviour depends on many operational factors (air flow and humidity, pressure,…), dimension and pellets characteristics (moisture, size, raw material, density, friability,…). In this paper, the first results and general performance of a 24 kW pellet fixed bed stove pilot plant are presented. The plant has been designed to study pellet combustion in the laboratory. The main targets are to reduce emissions of pollutants and to improve energy efficiency. Different situations can be simulated and tested due to its flexible design. Temperatures, pressures, flows and emissions are measured and analysed. An extensive study of different load conditions is presented through the application of both an experiment design technique and the later statistical analysis of the results. Fuel characterisation is also presented.     

Comparison of Downer and Riser Based Fluid Catalytic Cracking Process at High Severity Condition: A Pilot Plant Study

Integration of refining and petrochemicals offers economic benefits to both the industries. Converting low value refinery products to high value petrochemicals require novel processes and extra investment. Though FCC is not a new process to the refining industry, it still has a potential for modification to enhance light olefins demanded by reformulated gasoline and the petrochemical industry. In this article a novel, High Severity FCC process based on the downer reactor is presented. Supported by the pilot plant study and comparison with riser, it is shown that the downer FCC reduces backmixing, which is the main cause of gasoline overcracking. Reduction of backmixing reduces coke and dry gas formation, resulting in increased yield of gasoline. Despite the operation at higher temperature, there is reduction in the thermal cracking. Though the light olefins yield is lower in case of downer, the total yield of useful products (gasoline + light olefins) is higher in downer as compared to the same from a riser. The increased yield of gasoline from downer can be converted to light olefins by using ZSM-5 based additives.     

含油污泥减量化处理现场中试试验

研究分析了某油田含油污泥的组分特点,针对性地进行了实验。根据室内研究结果,提出了脱稳—絮凝—固液分离的技术路线,设计出中试设备并进行中试试验。中试设备的核心是反应脱稳罐,有效容积为1 m3、配备调速搅拌器,可满足不同转速的搅拌要求。油泥脱稳后进入筛网过滤器进行固液分离,分离水送回原水池处理,脱水油泥含油量达20%以上,可用作燃料。设备运行稳定,在脱稳剂加量为3%,PAM加量为400 mg/L时,形成絮体较大,固液分离效果明显,过滤速度快,分离水清澈,过滤2 h,剩余含油污泥含水率在60%左右。经脱水后的含油污泥量减少到原来的1/3左右,为后续的资源化利用提供了条件。现场试验结果与室内研究结果相符。     

胶态分散凝胶在马21断块砂岩油藏调驱中的应用

报道了由HPAM和金属离子,酚醛树脂组成的胶态分散凝胶（CDG）的基本组成,形成条件和性能参数,介绍了冀中河间马21断块间145井组CDG调驱设计要点（注入压力,段塞组成,注入量及注入工艺）及实施情况,分析了该井组CDG调驱结果,调驱液包括前置段塞[聚合物／复合交联剂浓度为1200/240mg/L),主段塞（800／100）及后置段塞（1000／200）,总量3200m3),注入时间24天,后续注水,间145井注入CDG后,对应3口油井先后见效,产油量增加,含水大幅度减少,水驱待特曲线表明后续水驱的波及效率和驱油效率都有所提高,本次CDG单井组调驱先导试验在经济上也是成功的。     

一种适应高多普勒频偏的突发传输高效导频图案

导频符号辅助调制技术广泛应用于数字通信系统的突发传输。在频偏范围较大和信噪比较低时,现有的前后式导频方案的频偏估计误差会远高于理论下界。该文研究了频偏估计最大似然检测量的主瓣和旁瓣分布,分析了对称分布导频图案在频偏估计时的模糊问题。在此基础上提出了一种新的混合对称式导频图案,并给出了相应的参数选取原则。新导频图案能够在较低的信噪比下具有大的频偏估计范围和较高的估计精度。仿真结果验证了新导频图案的良好性能。     

基于AMESim的先导式减压器性能仿真分析

选择先导式减压器设计方案,进行静态特性计算。使用工程系统仿真高级建模环境（Advanced Modeling Environment for performing Simulation of engineering systems, AMESim）对静态及动态特性进行仿真分析。仿真结果表明,不同结构要素需合理设置,以保证减压器性能满足要求。     

无线网络仿真的思变

主要讨论网络硬仿真系统（NES）如何应用于无线网络规划并致力于解决无线网络中的覆盖和干扰问题,减少优化工作量。     

Pilot‐Based Coding Scheme for Parametric Stereo in Enhanced aacPlus

We propose a pilot‐based coding (PBC) scheme for lossless bit rate reduction of parametric stereo (PS) in enhanced aacPlus. It uses PBC in addition to the existing frequency and time differential coding to encode and decode PS parameter indexes. We also design optimal Huffman codebooks (HCBs) for PBC in the proposed scheme. Experiments show that the proposed scheme is superior to the original coding scheme, where both the new coding structure and the optimal HCBs contribute to the bit rate reduction.     

Ozone Application for the Improvement of UASB Reactor Effluent I. Physical-Chemical and Biological Appraisal

Ozonation can improve the effluent characteristics of UASB (upflow anaerobic sludge blanket) reactors treating domestic sewage, by removing organic matter, solids, surfactants, color and microorganisms. In Brazil, part of the effluent of a 120 msup3; UASB reactor, fed with screened domestic sewage at an hydraulic retention time of 7 hours, was post-treated in a two-column ozonation system of 300 liters total volume. With a contact time of 50 minutes and ozone application dosage of 16.7 mg/L, the following removals were obtained at the ozonation step: 51‰ BOD, 56‰COD, 76‰ TSS, 62‰ color, and 91‰ surfactants. Pathogens and indicator organisms were inactivated to over 99.9‰. Ozonation completely destroyed Salmonella, protozoa cysts and helminth eggs and larvae.     

CPDLC交互通信人机界面设计研究

CPDLC（Controller Pilot Data Link Communication)是数据链技术在现代空中交通控制的应用之一。通过分析飞行任务的特殊性，说明人机界面设计是其实际应用的关键。从对RTCA DO219指令集的分析出发，对指令进行重新分类整理，设计综合人机界面显示单元，实现飞行员和控制台之间方便快速的对话磋商，并进行了仿真设计。