首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 46 毫秒
1.
以实现烟尘超低排放的河南平顶山发电分公司2×1030MW机组配套的超净电袋复合除尘器为研究对象,分析了超净电袋复合除尘技术的原理和措施,并介绍了该工程具体的工艺方案,通过现场实测及CEMS在线数据分析,系统验证了超净电袋复合除尘技术在燃烧劣质煤的大型机组上应用的可行性和稳定性,以及实现烟尘超低排放工艺技术的可行性。  相似文献   

2.
以出口首台实现烟尘超低排放的土耳其泽塔斯三期2×660MW机组超净电袋复合除尘器为研究对象,分析超净电袋复合除尘技术的原理和措施,并介绍了该工程的工艺方案,通过运行情况、测试结果及电厂反馈,证明超净电袋复合除尘技术大型化出口应用的可行性和稳定性。  相似文献   

3.
阐述了我国劣质煤发电在新形势下的发展趋势,分析了劣质煤机组实现烟尘超低排放的技术及工艺路线的研究现状,针对其存在的问题提出技术经济性更优的超净电袋复合除尘技术路线,并从技术角度全面分析了超净电袋复合除尘技术对劣质煤机组超低排放的适应性,通过工程案例验证了该技术在燃烧劣质煤的大型机组上应用的可行性和稳定性。  相似文献   

4.
文章对比了在超低排放背景下的各种除尘技术对氢氧化铝〔Al(OH)_3〕焙烧炉烟气净化的适应性,提出了其最佳可行技术,即高温超净电袋复合除尘技术,阐述了该技术的原理及特点,重点介绍了山东某厂1#炉3000t/d Al(OH)_3焙烧炉项目电除尘器改造配套采用高温超净电袋复合除尘器技术方案,性能测试结果表明经改造出口颗粒物的排放浓度小于5mg/Nm~3,达到超低排放的要求。该技术的成功应用,验证了其除尘效率高、运行阻力小、维护费用低、无二次污染等优点,可大幅提高副产物回收率,降低除尘设备电耗,减少排污费,具有良好的经济效益和社会效益。  相似文献   

5.
近年来,电袋复合除尘技术在燃煤锅炉烟气除尘行业的应用取得了快速发展,并实现了600MW、1000MW大型机组的突破。电袋复合除尘器已成为继电除尘器、袋式除尘器之后的新一代高效除尘设备。应用实践表明,电袋复合除尘器对煤种变化的适应性强,可长期保持低排放,并具有运行阻力低、占地面积小等优点。介绍了世界上首台1000MW机组电袋复合除尘器的开发和应用情况。  相似文献   

6.
随着国家对细微颗粒物的排放标准要求日趋严格,除尘技术也在不断发展与改进。电袋除尘器是将静电除尘器和布袋除尘器有机结合起来的新型除尘设备,能有效提高除尘效率,降低压力损失。文章对电袋除尘器的发展历程进行了回顾,对其工作原理及除尘机理进行了分析研究,旨在为电袋除尘器的发展及推广提供一定参考。  相似文献   

7.
介绍了新型DSC-M燃煤烟气干式超净技术,该技术通过循环流化床双段式吸收塔和超净布袋除尘器的有机结合,可实现脱硫、脱硝、除尘及多污染物协同治理,且没有废水产生、烟囱排烟温度高、烟囱无需防腐、排烟透明无视觉污染,真正实现燃煤烟气的超净排放要求。该技术已在包括20多台套300MW等级机组在内的上百台套燃煤机组上成功运用,并达到预期的超净排放目标,是新形势下烟气多污染物协同超净排放控制工艺的最佳可行技术之一。  相似文献   

8.
以某300MW火电机组配套除尘设备为例,从一次性投资、维护费用和运行费用等方面对电除尘器和电袋除尘器进行了技术经济比较,结果表明,当粉尘排放浓度≤50mg/Nm3时,选用电除尘器较适宜,但对更加严格的排放标准,选用电袋除尘器更好。  相似文献   

9.
结合脱硫脱硝除尘技术和焦炉废气的特性,提出焦炉烟囱尾气脱硫、脱硝、除尘超净排放的工艺,并对各工艺进行了技术经济分析,提出最优的工艺路线。  相似文献   

10.
金属纤维电袋复合除尘器结合了传统电除尘器和袋除尘器的优点,是一种新型的耐高温、耐腐蚀、高过滤精度、低阻力的工业除尘净化设备,可实现高温烟气粉尘的超低排放。文章介绍了金属纤维电袋复合除尘器的结构、特点,并结合实际工程应用,说明了金属纤维电袋复合除尘器可实现氢氧化铝焙烧炉尾部烟气的超低排放,可在氧化铝厂推广应用。  相似文献   

11.
Fire and logging in nutrient-poor temperate forests with certain ericaceous understory plants may convert the forests into heaths. The process of disturbance-induced heath formation is documented by using examples ofCalluna in western Europe,Kalmia in Newfoundland, andGaultheria (salal) in coastal British Columbia. In a cool, temperate climate, rapid vegetative growth ofCalluna, Kalmia, and salal following disturbance results in increasing organic accumulation (paludification), nutrient sequestration, soil acidification, and allelochemicals. These are thought to be the main reasons to conifer regeneration failure in disturbed habitats. If continuation in forest is a land-use objective, then temperate forests with an ericaceous understory should not be logged unless effective silvicultural methods are devised to control the ericaceous plants and restore forest regeneration. Preharvest vegetation control may be considered as an option. Failure to control the understory plants may lead to a long-term vegetation shift, from forest to heathland, particularly in nutrient-poor sites. Successful methods of controllingKalmia andGaultheria, however, have yet to be developed. While theKalmia- andGaultheria- dominated heathlands are undesirable in Canada and the Pacific Northwest, a wide range ofCalluna heathlands of western Europe are being conserved as natural and seminatural vegetation.  相似文献   

12.
In water stressed regions, water managers are exploring new horizons that would help in long‐range streamflow forecasts. Oceanic‐atmospheric oscillations have been shown to influence streamflow variability. In this study, long‐lead time streamflow forecasts are made using a multiclass kernel‐based data‐driven support vector machine (SVM) model. The extended streamflow records based on tree ring reconstructions were used to provide a longer time series data. Reconstructed data were used from 1658 to 1952 and the instrumental record was used from 1953 to 2007. Reconstructions for oceanic‐atmospheric oscillations included the El Niño‐Southern Oscillation, Pacific Decadal Oscillation, Atlantic Multidecadal Oscillation, and North Atlantic Oscillation. Streamflow forecasts using all four oscillations were made with one‐year to five‐year lead times for 21 gages in the western United States. This is the first study that uses both instrumental and reconstructed data of oscillations in SVM model to improve streamflow forecast lead time. SVM model was able to provide “satisfactory” to “very good” forecasts with one‐ to five‐year lead time for the selected gages. The use of all the oscillation indices helped in achieving better predictability compared to using individual oscillations. The SVM modeling results are better when compared with multiple linear regression model forecasts. The findings are statistical in nature and are expected to be useful for long‐term water resources planning and management.  相似文献   

13.
Urban ecological systems: scientific foundations and a decade of progress   总被引:9,自引:0,他引:9  
Urban ecological studies, including focus on cities, suburbs, and exurbs, while having deep roots in the early to mid 20th century, have burgeoned in the last several decades. We use the state factor approach to highlight the role of important aspects of climate, substrate, organisms, relief, and time in differentiating urban from non-urban areas, and for determining heterogeneity within spatially extensive metropolitan areas. In addition to reviewing key findings relevant to each state factor, we note the emergence of tentative "urban syndromes" concerning soils, streams, wildlife and plants, and homogenization of certain ecosystem functions, such as soil organic carbon dynamics. We note the utility of the ecosystem approach, the human ecosystem framework, and watersheds as integrative tools to tie information about multiple state factors together. The organismal component of urban complexes includes the social organization of the human population, and we review key modes by which human populations within urban areas are differentiated, and how such differentiation affects environmentally relevant actions. Emerging syntheses in land change science and ecological urban design are also summarized. The multifaceted frameworks and the growing urban knowledge base do however identify some pressing research needs.  相似文献   

14.
Urban gardens are important sources of sustenance for communities with limited access to food. Hence, this study focuses on food production in gardens in the Toledo metropolitan area in Northwest Ohio. We administered surveys to 150 garden managers from November 2014 to February 2015 in our attempt to better understand how neighbourhood racial composition and poverty levels are related to staffing and voluntarism, food production and distribution, the development of infrastructure, and the adoption of sustainability practices in urban gardens. The results from 30 gardens are presented in this paper. We used Geographic Information Systems to map the gardens and overlay the map with 2010 census data so that we could conduct demographic analyses of the neighbourhoods in which the gardens were located. Though the gardens were small – two acres or less – up to 46 varieties of food were grown in a single garden. Gardens also operated on small budgets. Food from the gardens was gifted or shared with friends, family, and neighbourhood residents. Gardens in predominantly minority neighbourhoods tended to have fewer institutional partners, less garden infrastructure, and had adopted fewer sustainable practices than gardens in predominantly White neighbourhoods. Nonetheless, residents of predominantly minority and high-poverty neighbourhoods participated in garden activities and influenced garden operations. Volunteering and staffing were racialised and gendered.  相似文献   

15.
Collisions with deer and other large animals are increasing, and the resulting economic costs and risks to public safety have made mitigation measures a priority for both city and wildlife managers. We created landscape models to describe and predict deer-vehicle collision (DVCs) within the City of Edmonton, Alberta. Models based on roadside characteristics revealed that DVCs occurred frequently where roadside vegetation was both denser and more diverse, and that DVCs were more likely to occur when the groomed width of roadside right-of-ways was smaller. No DVCs occurred where the width of the vegetation-free or manicured roadside buffer was greater than 40 m. Landscape-based models showed that DVCs were more likely in more heterogeneous landscapes where road densities were lower and speed limits were higher, and where non-forested vegetation such as farmland was in closer proximity to larger tracts of forest. These models can help wildlife and transportation managers to identify locations of high collision frequency for mitigation. Modifying certain landscape and roadside habitats can be an effective way to reduce deer-vehicle collisions.  相似文献   

16.
ABSTRACT: Mathematical models for predicting watershed surface flow responses are available, most of which are elaborate nonlinear numerical surface and channel flow models linked with infiltration models. Such models may be used to make predictions for ungaged areas, assuming an acceptable fitting of the model to the topography and roughness of the real system. For some application purposes, these models are impractical because of their complexity and expensive computer solutions. A procedure is developed that uses a complex model of an ungaged area to derive a simpler parametric nonlinear system model for repetitious simulation with input sequences. The predicted flow outputs are obtained with the simpler model at significant savings of money and time. The procedures for constructing a complex kinematic model of a 40 acre (161,880 m2) reference watershed and deriving the simpler system model are outlined. The results of predictions from both models are compared with a selected set of measured events, all having essentially the same initial conditions. Peak discharges ranged from 3 to 118 ft3/sec (0.085 to 3.34 m3/sec), which includes the largest event of record. The inherent limitations of lumped systems models are demonstrated, including the bias caused by their inability to model infiltration losses after rainfall ceases. Computer costs and times for the models were compared. The derived simple model has a cost advantage when repeated use of a model is required. Such an applications hydrologic model has an engineering tradeoff of reduced accuracy, and lumping bias, but is more economical for certain design purposes.  相似文献   

17.
Zimbabwean provincial plans were instituted to help in the achievement of the national goal of the creation of an egalitarian, socialist and integrated society. The national goal itself was adopted as an antithesis to the dualist society characterised by spatial, economic, social, politican and technological inequalities that Zimbabwe inherited from colonialism. This meant that provincial plans had to play both a functional (or growth allocating/distribution) and a territorial (or redistribution) role.

This paper reviews their role in achieving the national goal by examining their functions, content, structure and methodology. The paper concludes that because of their nature, provincial plans are not suitable tools for the achievement of the national goal.  相似文献   


18.
ABSTRACT: Sustained interest in and concern about the health status of the aquatic environment has resulted in extensive research focused on (1) effects of pollution on survival, growth, and reproduction of resource species at all life stages; (2) diseases of fish and shellfish, as they may be related to pollution and as they may serve as indicators of environmental stress; and (3) contaminant body burdens in fish and shellfish - their effects on the aquatic animals and their potential effects on humans. Effects, lethal and sublethal, of pollutants on life history stages of fish and shellfish have been documented, as have impacts on local stocks in badly degraded habitats, but as yet there has been no adequate quantitative demonstration of effects on entire aquatic species - probably because of the difficulty in sorting out relative effects of the many environmental factors that influence abundance. Sublethal effects, especially those that result in disease, have been examined intensively, and some diseases and disease syndromes have been associated statistically with pollution. Other pollution indicators (biochemical, physiological, genetic, behavioral, and ecological) have also received some attention, as have body burdens of contaminants in aquatic species. Research, especially that conducted during the past decade, has done much to clarify the many pathways and toxic effects of contaminants on aquatic animals, and has also helped to identify mechanisms for survival of fish and shellfish in the presence of environmental changes caused by human activities.  相似文献   

19.
Manganese entering impounded water will undergo a cyclic transformation. Oxidation precipitates manganese from top waters. At the bottom of the lake, biological activity will render manganese soluble by both intracellular as well as extracellular activity. The study was made to demonstrate that biological reduction and transformation, organometallic complexation, together with the presence of carbon dioxide and the lowering of pH all have some effect on the solubility of manganese. Dissolved manganese may be brought back to top waters during the lake overturn and therefore deteriorates the water quality.  相似文献   

20.
All major journalism ethical codes explicitly state that journalists should protect editorial copy from undue influence by outside sources. However, much of the previous research on agricultural information has concentrated on what information various media communicate (gatekeeping studies) or communication's role in increasing innovation adoption (diffusion studies). Few studies have concentrated specifically on organizational and structural constraints that might adversely affect agricultural journalists' ethical standards; those that have, focus largely on farm magazines. A study of newspaper reporters who cover agricultural news found that the most pressing ethical concern is the effect of advertiser (agri-business) pressure on editorial copy, and that their concerns in general parallel those of farm magazine writers and editors. The majority reported being in situations in which they might be exposed to advertiser pressure, including pressures to change or withhold editorial copy. Large minorities suggested that advertising pressures affect the overall environment in which agricultural journalists work, and more than one in ten said they allow advertiser pressures to influence editorial decisions. The newspaper reporters who cover agricultural beats showed slightly more resistance to advertiser pressure than did farm magazine editors in a parallel study.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号