旁通管定压在大高差集中供热系统的应用

介绍了旁通管定压在大高差地区的设计方法。结合工程实例,计算了旁通管的管径。     

长距离高扬程多级加压输水管道水锤防护工程实例

长距离高扬程输水管道水锤防护难度大,极易造成运行事故.根据长距离高扬程输水管道系统的特点并结合西北地区某县长距离输水工程,采用多级加压、各级泵站之间独立计算的方法,讨论了此类工程水锤防护方法,可为同类工程提供参考.     

住宅暖通设计

根据住宅设计要求和国家消防设计标准,介绍了住宅暖通设计中所包含的内容和在设计中经常遇到的一些问题,以使住宅暖通设计更加贴合用户角度,更安全、合理、人性化。     

浅谈交接性试验在地铁GIS柜中的应用

详细介绍了GIS的预防性试验项目和试验仪器及试验要求,结合具体工程实例,通过对35 kV GIS柜进行主回路导电电阻测试和交流耐压试验,阐述了交接性试验在地铁GIS柜中的应用,指出变接性试验是检测设备潜在缺陷的重要手段。     

预聚反应器轴流泵机械密封失效分析与解决方案

针对聚丙烯装置预聚反应器轴流泵P200机械密封在装置开工投用期间发生泄漏失效的问题,根据理论计算,确定增压活塞投用与停用的环管压力的临界值;结合实际受损机械密封分析,提出完善增压活塞的投用方案,并加强轴流泵停车期间,尤其是开车前的维护工作,防止杂质进入密封腔。实际运行证明了提出的解决方案能有效避免轴流泵机械密封的失效,保证装置的开车顺利。     

ZYG气液增压缸的原理及其应用

通过分析ZYG气液增压缸的结构和工作系统图分析了其工作原理,介绍其主要技术参数及应用场合。     

可控式增压复合油缸设计及其性能分析

针对大压力、小压力行程的重型液压设备的结构尺寸大、油泵功率大、利用系数低、液压系统复杂等问题,提出一种压力随机可调、工作效率高、结构紧凑、性能稳定可靠的复合式高增压油缸结构。对比分析了复合缸液压机和普通单缸液压机的工作过程;论述了复合缸液压机的运行原理和设计要求;介绍了可控式增压复合油缸性能及应用。结果表明:通过增压缸将液压系统提供的压力油转换为增压油提供给主油缸,使其产生大的压力输出,可有效地减小设备主机尺寸;通过控制缸随时进行高低压转换,各阶段速度压力按需配置,实现成形工艺的最优搭配,成形周期缩短;可以提高油泵的利用系数,减小泵站装机容量;液压系统工作负荷低,性能稳定可靠,寿命长。     

CO2 capture from dry flue gas by vacuum swing adsorption: A pilot plant study

The capture and concentration of CO₂ from a dry flue gas by vacuum swing adsorption (VSA) has been experimentally demonstrated in a pilot plant. The pilot plant has the provision for using two coupled columns that are each packed with approximately 41 kg of Zeochem zeolite 13X. Breakthrough experiments were first carried out by perturbing a N₂ saturated bed with 15% CO₂ and 85% N₂ feed, which is representative of a dry flue gas from coal‐fired power plants. The breakthrough results showed long plateaus in temperature profiles confirming a near adiabatic behavior. In the process study, a basic four‐step vacuum swing adsorption (VSA) cycle comprising the following steps: pressurization with feed, adsorption, forward blowdown, and reverse evacuation was investigated first. In the absence of any coupling among the steps, a single bed was used. With this cycle configuration, CO₂ was concentrated to 95.9 ± 1% with a recovery of 86.4 ± 5.6%. To improve the process performance, a four‐step cycle with light product pressurization (LPP) using two beds was investigated. This cycle was able to achieve 94.8 ± 1% purity and 89.7 ± 5.6% recovery. The Department of Energy requirements are 95% purity and 90% recovery. The proposed underlying physics of performance improvement of the four‐step cycle with LPP has also been experimentally validated. The pilot plant results were then used for detailed validation of a one‐dimensional, nonisothermal, and nonisobaric model. Both transient profiles of various measured variables and cyclic steady state performance results were compared with the model predictions, and they were in good agreement. The energy consumptions in the pilot plant experiments were 339–583 ± 36.7 kWh tonne^?1 CO₂ captured and they were significantly different from the theoretical power consumptions obtained from isentropic compression calculations. The productivities were 0.87–1.4 ± 0.07 tonne CO₂ m^?3 adsorbent day^?1. The results from our pilot plant were also compared with available results from other pilot plant studies on CO₂ capture from flue gas. © 2014 American Institute of Chemical Engineers AIChE J, 60: 1830–1842, 2014     

局部加压铝合金的宏观组织与成分偏析

研究了两种不同凝固特性的铝合金在局部加压条件下的宏观组织与成分偏析.结果表明:加压使加压杆周围的组织细化,糊状凝固特性的AC4B合金中等轴晶晶粒比层状凝固的ADC12细小.铜的成分分析显示AC4B合金易在加压杆下方形成负偏析;且离加压杆端面越近,偏析程度越大.ADC12合金仅在加压杆圆柱面下方5mm处有轻微的负偏析,其偏析程度不受加压开始时间的影响.与形成的负偏析相对应,在加压杆圆柱面周围则形成了正偏析.     

神木煤粉加压气流床气化中试试验研究

介绍了36t/d加压气流床气化中试装置主要设备、工艺流程及工艺条件的选择,并给出采用神木煤在气化压力3.0MPa、干粉煤投量1t/h条件下取得的主要试验数据:碳转化率98.9%,冷煤气效率83.2%,并给出相应的氧、煤耗,试验结果基本达到预期目的。