共查询到20条相似文献，搜索用时 484 毫秒
1.
A. VALAN ARASU T. SORNAKUMAR 《浙江大学学报(A卷英文版)》2008,9(3):416-422
Parabolic trough collectors （PTCs） are employed for a variety of applications including steam generation and hot water generation. This paper deals with the experimental results and an economic analysis of a new fibre reinforced plastic （FRP） based solar PTC with an embedded electronic controlled tracking system designed and developed for hot water generation in a restaurant in Madurai, India. The new collector performance has been tested according to ASHRAE Standard 93 （1986）. The performance of a new PTC hot water generation system with a well mixed hot water storage tank is investigated by a series of extensive tests over ten months period. The average maximum storage tank water temperature observed was 74.91℃, when no energy is withdrawn from the tank to the load during the collection period. The total cost of the new economic FRP based solar PTC for hot water generation with an embedded electronic controlled tracking system is Rs. 25000 （US$ 573） only. In the present work, life cycle savings （LCS） method is employed for a detailed economic analysis of the PTC system. A computer program is used as a tool for the economic analysis. The present worth of life cycle solar savings is evaluated for the new solar PTC hot water generation system that replaces an existing electric water heating system in the restaurant and attains a value of Rs. 23171.66 after 15 years, which is a significant saving. The LCS method and the MATLAB computer simulation program presented in this paper can be used to estimate the LCS of other renewable energy systems. 相似文献
2.
Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject. 相似文献
3.
卢义玉 《重庆大学学报(英文版)》2002,1(1):11-15
A new type jet, the oscillating & deflecting jet, is put forward and its oscillating and deflecting characteristics are investigated. The nozzle of the self-oscillating & deflecting water jet consists of an upstream nozzle, a downstream nozzle, an oscillating chamber and two switches. It is experimentally shown that the deflective angle may reach 9.53 degree. The generated pressure fluctuation is very regular and the jet can efficiently increase the ability for breaking and cutting by eliminating the water cushion effect associated with a continuous jet. 相似文献
4.
To improve the efficiency of the management of large farms, a digitalized system of economic statistics is designed based on the Internet platform of the digitalized agricultural integrated system of Friendship Farm, the largest farm in the world. The system can also realize data storage by using the access databank technology. A dynamic website system, based on ASP technology, is used to implement the on-line inquiry of the statistical index of the agricultural economy and the diagrams of the index every year. Furthermore, it can provide the value of comprehensive indicators of farms' economic profits for every year and a trend chart of the comprehensive appraisal of economic development, by using principal component analysis. An early-warning indicator boundary is decided based on the majority principle. The system can realize the farm's terminal data input with effective data-collecting channels and a normative gathering scope and system. This system breaks through the stand-alone database system in agricultural digitalized research to realize the database system in the Internet environment by integrating the existing technologies in China. The system lays a foundation for the further integrated research on the network platform of the digitalized agricultural integrated system in Friendship Farm. 相似文献
5.
WUBin 《重庆大学学报(英文版)》2002,1(1):56-60
In order to plow an access to low cost automation, the method to set up the most economical and optimized control system is studied. Such a system is achieved by adopting the field bus technologies based on net connection to form the hierarchical architecture and employing genetic algorithm to intelligently optimize the parameters of the topology structure at the field execution level and the parameters of a local controller. Praxis has proved that this realization can shorten the system development cycle, improve the system's reliability, and achieve conspicuous social economic benefits. 相似文献
6.
Increasing demand is fueling the booming polyurethane industry worldwide. An impeding issue for polyurethane industry is how to handle the large quantity of hydrogen chloride byproduct generated from the synthesis of intermediates, i.e., isocyanates. In the meantime, the traditional chloro-alkaline process suffers both from the high energy intensity of electrolysis method and the disparity in the chlorine and caustic soda market. To solve these problems, the state-of-the-art chlorine recycling technologies are reviewed and compared. Approaches for cost-effective utilization of chlorine in polyurethane industry are investigated. Chinese academies and enterprises’ on-going effort on the development of a novel hydrogen chloride oxidation process for the synthesis of chlorine is presented. With this process, the closed loop recycling of chlorine can be realized. Tremendous economic, environmental and social benefits can be expected. A wide adoption of this technology will significantly advance the sustainable development of polyurethane industry. 相似文献
7.
We established a hydrodynamic model to simulate the pollutant transport and decay process in the case of a pollution incident in the sections of the Yangtze and the Jialing passing through the city area of Chongqing. The Boussinesq assumptions and the Navier-Stokes equations of incompressible fluid were applied to setting up the pollutant diffusion equations and the equations for the decay process. E. coli was taken as the example pollutant, and chloride dosage, light, temperature and ultraviolet intensity were considered in the equations for bacterial decay process. The calculated values of the fluid velocities in the two rivers agree well with corresponding measured results, indicating an ideal accuracy of the model. In simulation, the concentration of E. coli in water was assumed to be zero before the accident. The upriver boundary velocity was ?1.35 m/s for the Jialing flow and 1.75 m/s for the Yangtze flow, and the downriver boundary was water depth set at 0. Simulation results show that the bacteria are transported downstream along the riverbank. A long and narrow pollutant belt develops at 12 h after the start of the accident ascribed to the quick longitudinal transfer. After the pollution sources are cut off, the pollutant concentration decreases slowly, mostly by advection and diffusion, suggesting inadequate self-purification ability of the rivers and the necessity of effective decontaminating measures in the case of a pollution incident. The model can be a useful tool for understanding the polluting situations of an improper discharge incident and evaluating the effects of decontaminating measures for the water body of the Three Gorges Reservoir. 相似文献
8.
WUBin 《重庆大学学报(英文版)》2002,1(1):56-60
In order to plow an access to low cost automation,the method to set up the most economical and optimized control system is studied.Such a system is achieved by adopting the field bus technologies based on net connection to form the hierarchical architecture and employing genetic algorithm to intelliently optimize the parameters of the topology structure at the field execution level and the parameters of a local controller,Praxios has proved that this realization can shorten the system development cycle,improve the systtem‘s reliability,and achieve conspicuous social economic benefits. 相似文献
9.
IAMTRAKUL Pawinee TEKNOMO Kardi GE Jian HOKAO Kazunori 《浙江大学学报(A卷英文版)》2005,6(8):900-906
INTRODUCTION Public parks are representative of city green ar-eas that provide numerous recreation opportunities to the people in the community. At the same time, public parks offer social, economic, and environmental benefits. High quality park service contributes to urban quality, but requires a large city government budget on personnel, parks resources, and admini-stration to maintain public parks’ high quality of ser-vice. In order to maintain and explain the budget for public parks… 相似文献
10.
伍成波 《重庆大学学报(英文版)》2003,2(2)
1. Introduction The bake-out and start-up technologies of aluminum reduction cells is one of the important factors affecting the service life of cells. The service life of cells is of importance to economic benefit in aluminum reduction cells production. Especially for big prebaked cells, the study on bake-out and start-up is even more important. The present methods of bake-out include aluminum fluid bake-out, coke granule bake-out and graphite bake-out [1,2]. The disadvantage of aluminum ba… 相似文献
11.
Among the numerous inland river basins in the arid northwest China, Shiyang River basin is known for its most serious water shortage that constrains its social and economic developments and for some of the worst eco-logical and environmental deterioration in China. The research on the value of water resources used for ecosystem is the basis for reasonable allocation of water resources between users of ecosystem and economic system. In this paper the concept of dynamic value for the ecosystem services is proposed. A modified coefficient for the ecosys-tem service value per unit area is proposed according to the cover degrees of biomes combined with expert consul-tation. Based on the developmental stage coefficient and scarcity of ecological resources, a dynamic evaluation method is proposed. The theoretical formula and simple calculation formula of the sharing benefits coefficient and benefits per unit ecological water utilization are proposed. The result shows that the benefit of unit ecological water utilization in the lower reach was greater than that in the upper reach in the Shiyang River basin. 相似文献
12.
通过对矿井水成分的分析,提出矿井水净化为饮用水处理方法,设计矿井水处理工艺及流程,既防止了矿井水外排对环境污染,又节省了水资源,增加经济效益和社会环境效益。 相似文献
13.
高校水电综合管理新模式探讨 总被引：4，自引：0，他引：4
薛秋茸 《五邑大学学报(社会科学版)》2005,7(1):88-91
水电费用是高等院校公共开支的重要组成部分，引入科学方法，加强水电管理，进一步节流减支极具研究价值和经济意义。高校应在水电管理现状基础上，树立系统思想，优化以定额管理为中心的水电综合管理模式，以期实现水电节流减支，提高办学效益。 相似文献
14.
南水北调中线工程水源区基于合理经济开发的环境保护 总被引：1，自引：0，他引：1
李益民 《南阳师范学院学报》2006,5(9):55-57
通过对南水北调中线工程水源区环境遭受破坏的原因分析,指出了不合理的经济开发是环境被破坏的根源,探讨了水源区环境保护的主动方式和被动方式,并提出了基于合理经济开发的主动式环境保护对策。 相似文献
15.
冯正国 《河北能源职业技术学院学报》2007,7(3):66-68
为节约用水,缓解水资源紧缺的矛盾,充分利用洗衣、洗澡等生活废水,通过对用水量的计算,得到每天排放的废水量,并以此为依据,设计出套管式生活废水二次利用积水器.不仅外观尺寸设计美观合理,而且从内部结构及工作原理方面进行了合理的设计,经实际使用后,能达到预期的节水效果,并取得了良好的经济效益和社会效益. 相似文献
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17.
ZHOU Hou-gui 《重庆大学学报(英文版)》2006,5(2):111-114
1 Introduction a Water resource of rivers is a reusable and invaluable natural resource. Peddle irrigation wheel, water mill and man-made channel in ancient times, and water gate, reservoir, dam, and artificial waterways nowadays show that man has been ex… 相似文献
18.
追求环境效益是商品包装中应有的价值取向,但包装设计者往往只重视商家的经济效益,而忽视了这一设计给生态环境带来的损害。在建设环境友好型和资源节约型社会背景下,实现商品包装中经济效益与环境效益的统一,显得尤为必要。 相似文献
19.
我国水环境的生态问题表现为天然水资源系统、水环境开发利用系统和水环境管理系统,三个系统之间紧密联系、互相制约。必须理顺三者之间的关系,在保持水环境系统尤其是天然水资源系统完整性的基础上,澄清功能,采取政治的、经济的、技术的措施,尤其是高效的行政、法律管理,才能保证我国水环境可持续发展战略的实现。 相似文献
20.
介绍了非洲东部和南部雨水管网系统中雨水回用的实践与经验,并介绍了在Sub-Saharan Africa开展的雨水回用工程实践情况,包括国家政策的调研、回用理念的构建、雨水系统的建设和回用技术的评估.雨水回用技术在非洲东南部地区被大力推广,并被普遍接受,应用于生活用水及农业用水的补充以及环境可持续发展建设的各个方面.截止目前,已有12个国家级的雨水回用机构建成,他们为雨水回用系统的建设提供整体规划和技术指导.政府和投资商也逐渐转变态度,为推进雨水回用技术在经济、制度和技术上提供了优惠政策.合理的土地与水体管理是雨水资源利用最大化的关键.除了政策和制度的协调外,还需要充足的预算支持来推动技术的广泛应用. 相似文献