内压缩流程空分设备高压板翅式换热器空气通道堵塞的分析

介绍了15000m3/h内压缩流程空分设备高压板翅式换热器空气通道被冰堵的故障现象,详细分析了故障原因,并阐述了查找过程和处理措施。     

Investigation of the performance of a staggered configuration of tidal turbines using CFD

This paper investigates the influence of wake interaction and blockage on the performance of individual turbines in a staggered configuration in a tidal stream farm using the CFD based Immersed Body Force turbine modelling method. The inflow condition to each turbine is unknown in advance making it difficult to apply the correct loading to individual devices. In such cases, it is necessary to establish an appropriate range of operating points by varying the loading or body forces in order to understand the influence of wake interaction and blockage on the performance of the individual devices. The performance of the downstream turbines was heavily affected by the wake interaction from the upstream turbines, though there were accelerated regions within the farm which could be potentially used to increase the overall power extraction from the farm. Laterally closely packed turbines can improve the performance of those turbines due to the blockage effect, but this could also affect the performance of downstream turbines. Thus balancing both the effect of blockage and wake interaction continues to be a huge challenge for optimising the performance of devices in a tidal stream farm.     

金属矿山溜井问题研究现状及方向

溜井在使用过程中频繁发生的堵塞现象和井壁变形破坏问题,已成为影响矿山安全高效生产的重要因素。将溜井问题归纳为溜井堵塞和井壁稳定性两大问题,并系统分析、总结了溜井问题的研究现状及存在问题。溜井堵塞问题表现为其底部放矿过程中井内物料流动中止,井壁稳定性问题主要表现为井壁变形、失稳和跨塌。研究表明：①矿石含水率、粉矿含量、放矿漏斗角、贮矿高度、贮矿时间以及矿岩块度与溜井直径之间的匹配关系,井壁支护结构脱落与井壁围岩垮塌产生的大块,以及溜井使用管理方面存在的问题,是造成溜井堵塞的主要原因;②矿（废）石的粒度分布特征及其物理力学特性,溜井工程围岩的地质结构特征及其应力场特征,溜井结构、井壁支护强度及其相互关系,是溜井井壁产生变形破坏的主要原因;③矿（废）石在溜井中运动与井壁接触并产生力的作用,使得溜井井壁受到冲击、剪切和摩擦损伤,是溜井井壁产生变形破坏的根本原因;④溜井堵塞后的爆破疏通和临近溜井的掘进爆破,加剧了对井壁的人为破坏。在上述分析的基础上,认为今后溜井问题的研究应着力于：①研究溜井堵塞各影响因素之间的关系,建立相关数学模型,探讨溜井结构及其相关尺寸的设计准则,预防溜井堵塞;②揭示溜井中物料的运动规律及其对井壁的力学作用机理,改善溜井结构及其支护方式,从根本上解决溜井稳定性问题;③研发应力释放技术和高应力环境下的工程支护技术,是解决深埋溜井井壁应力致裂破坏问题的主要研究方向;④从溜井的设计、使用与管理角度预防溜井堵塞,研发溜井堵塞的非爆破疏通技术,减轻爆破对井壁的损伤。     

甲醇制烯烃(MTO)反应器分布管堵塞原因分析及措施

为解决反应器分布管堵塞导致分布管压差上涨问题,寻求解决方法。对影响反应器分布管堵塞的因素,如MTO装置急冷水、水洗水、浓缩水、废甲醇水、压缩机段间凝液等进行试验和对分布管堵塞原因进行分析。通过优化污水汽提塔操作,控制污水汽提塔塔顶出料冷后温度高于120℃,将污水汽提塔塔顶的低温冷却器切换至高温冷却器和控制较低的pH值(8.0),减少了堵塞物的生成;对不凝气及浓缩水进行工艺改造优化了污水汽提塔的操作,解决了反应器分布管的堵塞问题。含有一定浓度醛酮类物质的浓缩水,在碱性环境中可以发生缩聚反应,在污水汽提塔系统内生成交联物,导致反应器分布管的堵塞。     

真空管道高速列车气动特性分析

为研究低压环境下真空管道高速列车的气动特性,建立低压环境下真空管道高速列车空气动力学计算的流体模型、数学模型和数值模型,研究管道压力(1.01×103～1.01×104 Pa)、阻塞比(0.2～0.7)和列车速度(600～1 000 km/h)对真空管道高速列车的阻力系数、气动阻力和气动热效应的影响。计算结果表明,在低压(1.01×103～1.01×104 Pa)环境下,真空管道中的空气流动可以采用连续介质模型描述,真空管道高速列车的绕流流场采用三维可压缩Navier-Stokes方程描述。高速列车的摩擦阻力系数远小于压差阻力系数,压差阻力系数和气动阻力系数基本上与管道压力和列车速度无关,而主要依赖于阻塞比。高速列车的气动阻力与管道压力近似呈线性关系,与列车速度近似成平方关系,且随着阻塞比的增加而增大。列车表面的最大温度基本上与管道压力无关,而主要由列车速度和阻塞比决定。     

Steady mixed convection across a confined square cylinder

The effects of cross-buoyancy and of Prandtl number on the flow and heat transfer characteristics of an isothermal square cylinder confined in a channel has been investigated here. The numerical results have been presented for the range of conditions as: 1 ≤ Re ≤ 30, 0.7 ≤ Pr ≤ 100 (the maximum value of Peclet number being 3000) and 0 ≤ Ri ≤ 1for a fixed blockage ratio of 0.125. The overall drag and lift coefficients, local and average Nusselt numbers and the representative streamline and isotherm plots are presented to elucidate the role of Reynolds number, Prandtl number and Richardson number. The drag coefficient is found to be less sensitive to the Richardson number than the lift coefficient.     

空压机运行效率下降的原因分析及处理

简介新钢25000m~3/h空分设备空压机运行效率下降时的运行参数,详细分析了空压机运行效率下降的原因,叙述中间冷却器堵塞物清理和酸洗过程以及取得的效果,并提出了保证空压机正常运行的相关注意事项。     

Blade number effect for a ducted wind turbine

Ducted wind turbine with multiple blades installed was believed to have a good wind power energy conversion effect. However, little information was available on how to design a good ducted wind turbine. In this paper the effects of blade number on a ducted wind turbine performance is studied. Numerical studies using CFD method to simulate the wind turbine performance were adopted. The duct is a converging-diverging nozzle with the turbine blades located at the throat. A rated output of a 1-kW turbine is adopted as the baseline design. It was found that the blade geometry, stagger angle, and number of blades have different duct blockage effects, and do affect the turbine performance (specifically the power coefficient and torque coefficient, etc.). The fewer number of blades has higher through flow speed, while the larger number of blades provides larger torque. The best power coefficient lies in between the two extremes. The appropriate number of blades is important to match the generator performance curve for optimal overall performance and efficiency. This paper was presented at the 9^th Asian International Conference on Fluid Machinery (AICFM9), Jeju Korea, October 16–19, 2007.     

高温缓速酸解堵技术研究与应用

为解决中原油田文东文南高温低渗油层解堵存在的技术难题,研制了高温缓速、深部穿透的解堵剂配方.用缓速酸主剂、高温酸化缓蚀剂,以及油水互溶剂、粘土防膨剂、铁离子稳定剂等酸液添加剂进行复配,优化筛选,得到综合性能优良的高温缓速解堵剂配方.文中对解堵剂配方性能进行了全面评价.该解堵剂比常规土酸缓速率提高94%,可应用于150 ℃的地层,现场应用增油增注效果显著.     

Performance analysis for glass furnace regenerator

Glass manufacturing is an energy intensive process where fossil fuel is used to maintain high temperature (about 1700 °C) for glass melting. Heat recovery from flue gas (1350–1500 °C) is usually in the form of combustion air pre-heating (900–1200 °C) using a regenerator. Dust from flue gas which is carried over from the furnace gets deposited in the regenerator storage matrix path. This leads to a deterioration of regenerator efficiency. A regenerator model is developed to estimate the actual performance of the regenerator and to compare it with the target performance. The proposed model is based on mass and energy balance of streams along with heat transfer characteristic equations. The model is illustrated for a 130 TPD (Ton per Day) furnace regenerator of an industrial glass plant at Mumbai, India. Model results for the regenerator studied indicate a blockage of 50% on the doghouse side and 22% on the non-doghouse side of the regenerator. The actual performance of the regenerator is found to be 7% lower than its target performance for the doghouse side regenerator. The model developed can also be used in other industrial sectors like steel, chemical etc.