电站锅炉制粉系统的爆炸原因与防范对策

火力发电厂制粉系统爆炸事故时有发生 ,重大设备损坏 ,造成了严重的经济损失。本文通过分析研究 ,找出制粉系统爆炸的原因 ,从措施上、煤的质量控制上及制粉系统结构改造上提出了防范的对策。     

空分设备系统操作中的物料平衡

本文以济南鲍德气体有限公司 2 0 0 0 0m3 /h空分设备为例 ,从物料平衡的观点出发 ,阐述了操作中一些应注意的问题及解决的措施。     

Numerical simulations of specimen size and mismatch effects in ductile crack growth - Part II: Near-tip stress fields

The effect of ductile crack growth on the near tip stress field in two different specimen geometries has been investigated. For homogeneous specimens it is observed that the peak stress level increases with ductile crack growth. The effect is most pronounced up to about 1 mm of crack growth. For low and intermediate hardening there is a significant effect of specimen size on the stress level. In case of mismatch in yield stress, the simulations show that the increase in stress level in the material with the lower yield stress is of a similar magnitude as is the case for stationary cracks. In case of ductile crack growth deviation from the original crack plane occurs, the highest stresses are still found close to the interface, and not in front of the current crack tip.     

Grain Growth Behavior of 5Cr21Mn9Ni4N Steel Micro-Alloyed by Rare Earth

Grain growth behavior of 5Cr21Mn9Ni4NRE steel was experimentally studied at various solid solution treatment temperatures and holding for different times. The experimental results show that the 5Cr21Mn9Ni4NRE steel has the feature of sharp austenite grain coarsening after solid solution treatment at the temperature above 1150 ℃. RE added in the steel has the benefit to restrain grain growth and increase grain growth activation energy.     

三角函数型增长曲线预测油田开发指标

提出了用三角函数表示的一类用于油田开发指标预测的增长曲线共6条，从而进一步完善和丰富了现有的增长曲线法。提出和推导了它们的Np-t、Qt-t、Qt-Np关系式、（Np/NRmax)Qtmax准数计算式以及参数求解式。其特片研究表明，它们特征相近；（Np/NRamx)Qtmax变化范围为0-0.36785，属于峰值产量出现在油田开发初期的情况，其Qt-Np关系为一不对称的拱形曲线。提出了求取曲线参数的过原点重复线性回归法。双河油田的实例表明该方法有一定实用价值。     

公路边坡培植柠条的探讨

介绍了河曲公路所处的自然环境 ,阐述了人工铲草的利与弊 ,进而提出了边坡培植柠条的效益分析 ,并对培植柠条的苗期管理及与养护生产的关系进行了介绍     

Optimized species growth in epoxy polymerization with real-coded NSGA-II

Satisfaction of twin objectives of maximization of M_n along with minimization of PDI do not necessarily guarantee the maximization of concentration of desired species in a semibatch epoxy polymerization process. As the final product consists of a number of polymer species, a need is felt to perform an advanced optimization study to come up with such process conditions for which the selective growth of a particular polymer species is maximized in minimum possible processing time and the population of other species should be at their lowest values. These above-mentioned conflicting objectives frame the platform for a multi-objective optimization problem, which is solved here using a real-coded non-dominated sorting genetic algorithm or NSGA II and Pareto optimal solutions are obtained. The decision variables are discrete addition rates of various ingredients, e.g. the amount of addition of bisphenol-A (a monomer), sodium hydroxide and epichlorohydrin at different time steps. All species balance equations, bounds on M_n, PDI and addition amounts are treated as constraints. Results are very promising in terms of optimized operations for selective enhancement of desired polymer species for the epoxy polymerization process. Total additions are kept very close to available experimental conditions to minimize probable extrapolation errors. It has been observed that preferential oligomer production is extremely difficult for epoxy polymerization. Lower chain polymers are the only choice for a good quality, stable polymer product.     

Grain growth kinetics in Dy-doped Bi0.5Na0.5TiO3 ceramics

Dysprosium-doped bismuth sodium titanate ceramics were prepared using the conventional mixed-oxide method. The amount of dysprosium used was varied from 0 to 2 at.%. The mixed powders were calcined at 800 °C and checked for phase purity using X-ray diffraction technique. The calcined powders were then cold-pressed into pellets and sintered at 1050 °C for the time ranging from 2 to 48 h. The ceramics were checked for phases and microstructures using an X-ray diffractometer and a scanning electron microscope, respectively. The analysis showed that undoped BNT ceramics sintered at longer time exhibited a significant grain growth with non-uniform grain size distribution and shape. The Dy-doped BNT however showed a much more limited grain growth behavior, resulting in smaller grain size and more equiaxed grain shape. It was also found that all Dy-doped BNT ceramics sintered at 48 h possessed lower porosity than those sintered for shorter time.     

探讨电石法PVC烟气治理方法

分析了电石法PVC生产链中电石炉烟气及电厂烟气二氧化硫的排放情况,指出利用电石炉烟气中的CO合成氨、再将合成氨用于燃煤电厂烟气的"氨法"脱硫是具有较大应用潜力的循环经济产业链。