临海高等级公路灌河大桥钢锚梁及钢牛腿制造

介绍了灌河大桥钢锚梁与钢牛腿的结构特点,结合生产实际情况,分析了钢锚梁及钢牛腿制造过程中的关键工艺及控制要点,以提高制造精度,消减焊接变形,从而保证钢锚梁、钢牛腿结构的质量。     

冰蓄冷系统与空气冷却器在啤酒厂的应用分析

冬季冰蓄冷与空气冷却器的组合系统运行模式。针对不同负荷情况冰蓄冷与空气冷却器如何与系统负荷匹配。     

山区高速公路装配式梁桥设计探讨

结合山区高速公路特点，对山区高速公路装配式梁桥设计进行了探讨，介绍了山区高速公路装配式梁桥的设计要点，包括跨径的选择组合，墩台形式的选择两方面内容，指出应根据水文、地形、地质、环境、技术、交通等因素综合考虑。     

LCI (Life cycle inventory) analysis of fuels and electricity generation in Singapore

This article offers a unique three-stage approach in LCI analysis for generating the environmental profile of electricity generation in Singapore. The first stage focuses on fuels delivered to Singapore, next on electricity generated from various types of power production plants. The third stage integrates the entire life cycle study. The final gate-to-gate results show that the total CO₂ emissions from the national grid are 455.6 kg CO₂ per MWh without any loss in transmission and 467.0 kg CO₂ per MWh with 2.5% losses. The results for the entire cradle-to-gate energy production are: 586.3 kg CO₂ per MWh without considering any losses and 601.0 kg CO₂ per MWh with 2.5% transmission loss. For the rest of the LCI, the cradle-to-gate results (per MWh) are kg 0.19 CO (carbon monoxide), 0.06 kg N₂O (nitrous oxide), 1.94–1.99 kg NO_x (nitrogen oxides), 2.94–3.01 kg SO_x (sulphur oxides), 0.064–0.066 kg VOC (volatile organic compounds) and 0.078–0.080 kg PM (particulate matters). From gate-to-gate, the results are 0.12 kg CO, 0.0016 kg N₂O, 1.42–1.46 kg NO_x, 2.56–2.62 kg SO_x, 0.033–0.034 kg VOC and 0.067–0.069 kg PM. Emissions of CO₂ from energy generation, climate change mitigation and policies for energy security are also discussed.     

Designing of primary air nozzles for large-scale CFB boilers in a combined numerical-experimental approach

The article presents a numerical-experimental approach for designing the primary air nozzles working with a large-scale Circulating Fluidized Bed (CFB) boiler. An analysis of the criteria that must be satisfied by CFB air grids has been made and it has been demonstrated that the existing correlations which are used in designing air grids are not possible to be utilized for determining the optimal nozzle design. On the example of a prototype nozzle design, based on the proposed design algorithm, the results of both numerical simulations and laboratory tests, whose aim was to determine the optimal geometry of a nozzle operating with a 235 MW_e asymmetric-design CFB boiler, are presented.     

Temperature and Quality Characteristics of Infrared Radiation–Dried Kelp at Different Peak Wavelengths

Drying experiments on kelp (seaweed species) were conducted using air drying (AD) and infrared radiation drying (IRD) at different emission peak wavelengths of 2.4, 3.0, 5.0, and 6.0 µm. Temperature characteristics of the dried kelp were determined in terms of temperature distribution and surface–interior temperature variation. Rehydrated ratio, color, and texture before and after rehydration were measured to evaluate the quality of dried kelp products. Dielectric properties were also studied to observe the characteristics of rehydrated dried products. The results indicated that the total drying time required for IRD products was approximately 120 min, reduced by 56% compared to AD (275 min). Infrared-dried products at 2.4 μm wavelength and AD products were found to be more uniform from the thermal images and had higher rehydration ratios compared to others. IR-2.4 rehydrated products were the closest to blanched samples in hardness, springiness, cohesiveness, and chewiness. This research work concluded that infrared radiation drying has potential to be used for drying of kelp.     

气力输送中气量控制元件的选择

介绍了减压阀、比例阀、过滤器、LAVAL管以及流量控制元件在气力输送供气管道中的选择;分析了其主要性能、设计计算和选用时应注意的问题。     

冷箱内塔支架的结构优化

运用大型有限元分析软件ANSYS,对空分设备常用的经验模型的塔支架的承载能力进行了分析,提出了几种改进措施,研究不同结构形式的承载能力。应用ASME《锅炉和压力容器》标准第八卷第二册的设计准则对在最大承载能力下的塔支架最大应力点进行了评定,得到了不同结构塔支架的特点和应用范围。     

我国桥梁防腐蚀技术现状与展望

如何提高桥梁结构耐久性,延长其使用寿命期,达到长效、绿色环保、具有全寿命经济性是21世纪必须面对的挑战。介绍了我国桥梁结构防腐蚀技术现状,并对未来的发展提出了建议。     

降水对桥基影响的三维渗流–应力耦合分析

 近邻桥梁进行降水施工时，地层的固结变形导致桥梁基础变形，当桥梁的基础变形过过大时，可能危及桥梁的安全和正常运行。为了预测降水过程中桥梁基础的空间响应和评估其安全状态，建立三维非饱和渗流–应力耦合分析数学模型，同时，运用ABAQUS软件，建立地层、地下水、桥梁相互作用的三维有限元模型。采用直接耦合分析方法，对近邻桥基进行降水施工时的动态降水过程进行三维仿真模拟。模拟结果表明，水位下降10 m时，降水所引起的地表最大沉降值为21.37 mm，桥基的最大沉降值为19.56 mm，相邻桥基的差异沉降不到2 mm，表明降水期间桥基没有安全隐患，现有的降水方案是可行的。通过将沉降计算值与现场量测值比较分析，两者数据吻合较好，表明所提出的计算模型和分析方法是合理的，可为类似问题的研究提供了借鉴和参考。