Simulation and analysis of a combined cycle heat and power plant process

The regulations of process efficiency and stricter environmental policies require analysis of large-scale thermal energy systems to produce highly efficient, cost effective and low environmental impact energy. For analysis, it is beneficial to simulate an energy system. In this paper, simulation models are developed for the analysis of a combined cycle heat and power plant located in Göteborg, Sweden. With the help of simulation models, characteristics between district heating (DH) water temperature and key parameters such as overall district heat duty, electrical power and electrical efficiency has been developed. The characteristics are useful to estimate and maximize the key parameters during varying DH water temperature. According to a comparison between the full-load simulation models of 2006 and 2013 for the selected power plant, a loss of 2 MW is noticed for gas turbine and a loss of 2.18 MW of heat flow occurs for heat recovery steam generator in the year 2013. The feasibility analysis of modifying the connection between DH economizer and main DH line provides good performance indicators in a winter scenario. The conclusions in this paper are good references to plan and improve the performance of existing large-scale thermal power plants.     

某地下商场紧急情况下人员疏散实验研究

地下商场紧急情况下人员疏散过程非常复杂,受到众多因素的影响,如人员自身因素、环境因素等。通过设计并实施人员疏散实验,同时对实验参与人员开展问卷调查,分析了地下商场紧急情况下人员疏散特性及借用相邻防火分区防火门作为安全出口对疏散过程的影响;从疏散演习实验过程中人员出口选择、疏散时间及出口流率、疏散行为等三方面内容对实验结果进行了分析和讨论。     

Electromagnetic Action of Heavy-Current Equipment Operating With Power Frequency

The paper presents an analysis of the effect of magnetic fields of power frequency generated by heavy-current electric equipment on the environment. The results of computation and measurements of the magnetic field in the vicinity of power busducts are included. Possible hazards are considered that result from the effects of the magnetic field on workers present in the vicinity of busducts as well as secondary hazards caused by the degrading effect of the magnetic field on ferromagnetic structural materials (in reinforced concrete structures). Attention is given to an ergonomic aspect of interaction of the magnetic field with cathode ray tube computer monitors (annoying oscillation of the image).     

Comparison of Two Methods for Judging Distances Near Overhead Power Lines

Sixteen certified crane operators performed several series of boom movements toward a segment of a typical power line using a 100-ton lifting capacity crane equipped with an 18-m boom, a single lifting cable, and a hard ball hook. The operators were instructed to stop the crane movement when the lifting cable reached the edge of the danger zone located 3 m from the power line. To achieve each maneuver, they evaluated the distance between the nearest wire and their crane using two methods: free sighting and the use of highly visible markers delineating the edge of the danger zone. The dependent measure was the distance between the lifting cable and the edge of the danger zone. Results showed that operators were generally unreliable when judging the distance between their crane and the power line when sighting the power line directly, but the use of markers proved to be much more precise and reliable in targeting the edge of the danger zone.     

TVS管失效原因分析

TVS管是一种常见的浪涌抑制器件,但如果使用不当容易损坏。本文从大量的调查研究中,选取几个典型的TVS管失效案例,详细分析失效原因,并将这些原因进行总结,提出有效的整改办法。     

风力发电设备在我国不同气候条件下环境适应性分析

风力发电设备的环境适应性问题已经引起风电企业的重视,本文介绍了温度、湿度、盐雾、低气压、台风、雷电等环境因素对风力发电设备性能的影响,总结了我国不同地区和不同季节应该关注不同的环境因素,提出了风力发电设备在不同环境因素作用下的防护措施。     

From wasteland to waste site: the role of discourse in nuclear power's environmental injustices

The purpose of this essay is twofold. First, I examine interdisciplinary literature to reveal the environmental injustices associated with the front and back ends of nuclear power production in the USA – Uranium mining and high-level nuclear waste (HLW) storage. Second, I argue that the injustices associated with nuclear power are upheld, in part, through discourse. This essay examines how the term “wasteland” is invoked in relation to HLW waste storage in the USA and contributes to the discursive formation of nuclear colonialism. Examination of this discourse not only contributes to current literature on nuclear colonialism but also to environmental justice research by arguing for the importance of examining the discursive aspects of environmental injustices. Further, the essay adds to current scholarship in energy justice by highlighting the environmental injustices associated with nuclear power.     

冷循环便携式半导体降温服设计及制冷性能分析

为缓解高温环境下劳动人员面临的热害问题,设计1种利用半导体制冷片作为制冷源的便携式冷循环降温服,并在高温环境下测试其降温性能.结果表明:在总电源功率100 W、环境温度30℃的情况下,运行12 min后,制冷水温度降低至15.7℃.降温服稳定运行状态下制冷功率为340.4 W.系统运行环境温度对制冷系统的制冷性能有显著...     

同异反向量模型在电厂安全评价中的应用

根据集对分析理论,针对安全评价系统的不确定性特点,采用了同异反向量模型对某电厂进行安全评价,评价结果与原文献吻合.该方法数学表达式简单,计算方便,物理意义明确.在安全评价过程中,差异度系数I的不同取值,反映了该电厂安全状况的变化,是安全管理工作的"晴雨表",可以使安全状况受到"增益"或"惩罚",映射出安全管理工作的重要性.这种方法为企业管理者提供了量化分析,使管理者对企业的安全程度及发展趋势有了更确切的了解,为安全管理工作提供依据.