一种复合阻垢剂在玉米浆蒸发器上的应用研究

通过对某淀粉厂玉米浆蒸发器上的玉米浆、垢样进行分析,并结合外在控制指标对玉米浆质量的影响,研究了该玉米浆蒸发器的结垢问题。结果表明,该玉米浆蒸发器有明显的碳酸钙、硫酸钙结垢倾向。针对玉米浆蒸发器温度较高、玉米浆中有机质含量高、粘度高的特点,开发出一种适合该环境的复合型阻垢剂。现场应用研究表明,当加药浓度为100 ppm时,成垢离子Ca~(2+)、SO_4~(2-)、CO_3~(2-)的保有率均有明显提高,玉米浆蒸发器的结垢倾向得到了有效控制。     

Quantitative biofouling diagnosis in full scale nanofiltration and reverse osmosis installations

Biofilm accumulation in nanofiltration and reverse osmosis membrane elements results in a relative increase of normalised pressure drop (ΔNPD). However, an increase in ΔNPD is not exclusively linked to biofouling. In order to quantify biofouling, the biomass parameters adenosine triphosphate (ATP), total cell count and heterotrophic plate count in membrane elements were investigated during membrane autopsies and compared with ΔNPD in test rigs and 15 full scale investigations with different types of feed water. The combination of biomass related parameters ATP and total cell count in membrane elements seem to be suitable parameters for diagnosis of biofouling, whereas plate counts were not appropriate to assess biofouling. The applied ΔNPD measurement was too insensitive for early detection of fouling. Measurements of biological parameters in the water were shown to be not appropriate in quantifying biofouling. Evidently, there is a need for a practical tool, sensitive pressure drop data and systematic research.     

Scaling fire whirls

A fire whirl in an open space can cause devastating damage as was experienced in Hifukusho-ato, Tokyo, after the Great Kanto Earthquake in 1921. To understand the generation mechanism of the open-space fire whirls, 1/1000th scale-model experiments were conducted in a large, low-speed open-loop wind tunnel. In analyzing the experiments, there was found to be a critical lateral wind velocity that generated intense fire whirls. A scaling law that predicts the critical wind velocity was developed and validated by various data including scale-model experiments by other researchers and real urban fire whirls. A dimensional analysis is conducted to understand the effect of flow circulation on the increase in flame height. The simple analysis was supported by the results of numerical simulations by other researchers.     

油浆阻垢剂的工业应用

油浆系统是催化分馏系统的核心,其运行好坏直接影响整套催化装置的安、稳、长、优生产。近年来,随着原料油的密度越来越重,导致油浆系统的结垢越发严重,轻者造成装置减产,重者迫使装置停工。文内分析了油浆系统的结垢机理,介绍了洛阳石化总厂在增上阻垢剂之前采取的相应措施,并结合油浆系统的结垢原因阐述了油浆阻垢剂的作用原理。该厂于1996年增上了油浆阻垢剂注入系统,装置经过两个生产周期的运行,油浆循环量始终维持在正常水平,装置未出现因设备或管线堵塞而产生的不良后果,油浆系统可调控自如。并对油浆阻垢剂加注前后,泊浆系统操作参数进行了对比,通过对比看出,管线和设备的结垢问题基本得到了解决。油浆阻垢剂投用3年来,减轻了油浆系统的结垢问题,消除了事故隐患,为催化装置的长周期安全运行提供了保障,每年可增加效益170余万元。     

清洗高压注水管线硬质垢的圆盘清管器

针对油田高压注水管线硬质垢的清洗难题,研制开发了一种加强型圆盘清管器。通过现场试验,确定了清洗工艺流程和参数,同时验证这是一种较理想的机具,除垢率达 ９５％以上,且操作简单成本低廉,值得推广应用。     

超宽带SAR利用改进CS算法成像

在原始Chirp Scaling（CS）算法的基础上．详细推导了改进CS算法．并利用改进CS算法对超宽带合成孔径雷达（UWB SAR）进行成像。将成像结果与原始算法的成像结果比较后，其结果证明该算法突破了原始算法的局限性．能对大处理角的超宽带合成孔径雷达成像。     

循环冷却水系统腐蚀情况分析及药剂控制方法

循环冷却水系统是天然气处理厂的重要组成部分,循环水量占厂内工业用水的60%以上。但循环冷却水系统在运行过程中通常会产生腐蚀、结垢、细菌滋生等问题,影响系统的正常运行。通过对天然气处理厂循环冷却水系统常见腐蚀的类型和腐蚀因素的分析,结合现行循环冷却水处理设计规范的有关规定,针对性总结了各种防腐控制方式的应用以及对主要控制指标和效果的影响。     

基于混合任务模型的动态电压调度在无线传感器网络中的应用

为了最大限度节约能量,延长无线传感器网络(WSN)的使用寿命,针对计算复杂度较高的WSN应用背景及其普遍存在的任务模式,提出一种相对更通用的、基于混合任务模型的动态电压调度算法(H-DVS)。H-DVS算法能在任务相对期限没有限制的情况下,与最早截止时间优先(EDF)调度算法结合,支持周期任务和零散任务同时存在的混合任务模型。H-DVS根据CPU的工作负载,由调频(FM)因子对CPU进行实时电压和频率调节,从而在降低能耗的同时保证任务的实时性要求。理论分析和仿真实验结果表明,该方法可行且有效。     

基于能量消耗模型的WSN动态电压调节算法

为了降低WSN中弱硬实时系统的能量消耗,应用离散事件系统（DES）框架中的优化原理,建立数学模型,得到了能量消耗的目标函数,为了最小化目标函数,利用线性规划方法进行求解,得到一种可扩展的低复杂度算法来进行动态电压调节（DVS）。并对算法进行了模型实例计算,结果表明,优化的DVS算法能在满足弱硬实时系统时限要求的基础上更大程度节省节点能量。     

Effects of viscous heating,fluid property variation,velocity slip,and temperature jump on convection through parallel plate and circular microchannels

Theoretical results, based on perturbation techniques, are presented for fully developed, both hydrodynamically and thermally, forced convection in both parallel plate and circular microchannels subject to isoflux wall boundary condition. Scaling effects, including variable property, viscous dissipation, velocity slip, and temperature jump, are studied for flow of both gases and liquids. The interactions between the aforementioned effects, due to temperature-dependence of the fluid properties that couples the momentum and thermal energy equation, are also examined in detail.