工程咨询甲级；工程设计综合资质甲级（可承接各行业、各等级的建设工程设计业务及从事资质证书许可范围内相应的建设工程总承包及项目管理和相关的技术与管理服务）；工程勘察综合类甲级；电力工程监理甲级（可开展相应类别建设工程的项目管理、技术咨询等业务）；承包与其实力、规模、业绩相适应的国外工程项目及对外派遣实施上述境外工程所需的劳务人员；测绘甲级；水土保持方案编制；房屋建筑工程监理乙级；特种设备设计（压力管道）；工程招标代理机构暂定级；建设工程设备、材料的销售及技术服务；售电；工程试验、检测、监测。
[Purposes] Most of the current research focuses on high strength steel axial compression members, and the cross-section forms are mostly welded H-shaped sections and box sections. However, there are few studies focusing on the mechanical properties of Q690 high strength steel pipe under bending, especially the different failure characteristics and their boundaries of flexural members with changing slenderness ratio have not been systematically studied. [Methods] Numerical analyses were carried out for the mechanical properties and instability mechanism of Q690 high strength steel tubular bending members. The effects of initial imperfections such as residual stress, pre-buckling deformation, and material plasticity on stable bearing capacity were investigated, and different failure characteristics were defined when slenderness ratio was changed. [Findings] According to on the analysis results, the bending bearing capacity curves of Q690 high strength steel pipe are obtained by the method in the European Code for Design of Steel Structures EN1993-1-6(2007), and the influence parameters of the bearing capacity curves at different stages are determined. The calculation formulae of the ultimate bearing capacity of members at different stages are proposed. This work provides scientific basis for the revision of steel structure design standard and high strength steel design standard in the future, and also provides theoretical support and design basis for the wide use of Q690 high strength steel round tube members in wind power tower, large span transmission tower, and substation framework.
To avoid the problems of the heat storage process in the compressed air energy storage system, reduce the generation of compression heat, and realize the efficient utilization of compression heat, a novel integrated compressed air energy storage system is proposed in this paper. The thermo-economic model of the system is established, and the thermodynamic and economic performance of the system under typical working conditions is studied. The influence law of key parameters on thermodynamic performance is analyzed, and the multi-objective optimization is carried out by the genetic algorithm. The results show that, under typical working conditions, the electrical-electrical efficiency and the exergy efficiency of the system are 63.86% and 58.18%, respectively, while air expander and pre-compressors have relatively high exergy destruction, accounting for 17.3% and 15.6% of the total exergy destruction, and the levelized cost of electricity for the system is RMB 1.036/（kW·h）. The sensitivity analysis shows that the optimal evaporation pressure exists in the Karina cycle to maximize the thermodynamic performance of the system. The system efficiency increases with the increase of the inlet pressure of the vessel, the maximum pressure of the reservoir, and the temperature of waste water, while the energy storage density of the system increases with the increase of the cyclic compression numbers linearly. The multi-objective optimization results reveal that the optimal exergy efficiency and levelized cost of electricity are 59.1% and RMB 0.962/（kW·h）, respectively. This paper presents a new solution for the design of the compressed air energy storage system, the system has a good prospect in the comprehensive utilization of industrial waste heat, and the analysis and optimization results can provide a theoretical basis for the engineering application of the proposed system.
