水喷雾灭火及低倍数泡沫灭火系统在油罐消防的应用

介绍油罐区设置固定式水喷雾消防冷却水系统及固定式低倍数泡沫灭火系统,并简述水消防系统选择、水雾喷头及空气泡沫产生器的选型、布置、系统环形供水管布置和油罐区消防供水等问题。     

厌氧池/人工湿地/生物塘系统处理奶牛养殖场废水

采用厌氧池/人工湿地/生物塘的组合工艺对某奶牛养殖场废水进行处理.结果表明,该系统的处理效果良好,SS和COD主要在厌氧池和人工湿地中被去除,NH 4-N、TN和TP主要在人工湿地和生物塘中被去除,整个系统对SS、COD、NH 4-N、TN和TP的平均去除率分别为91%、74%、72%、62%和85%,出水水质可达到<农田灌溉水质标准>(GB 5084-2005)的要求.该系统的成本低廉且易于运行维护,具有良好的经济效益与环境效益.     

Exploring public preferences for traditional farming landscapes

Given that an increasing share of budgetary resources are now being spent on measures aimed at protecting the visual quality of agricultural landscapes it will be important to better understand individuals’ landscape preferences and the factors that influence those preferences. Within this context, using a nationally representive survey of Irish residents, the central aim of this study was to gain more insight into people's preferences regarding traditional farming landscapes. Individuals rated agricultural landscapes in terms of beauty quite highly but given a choice prefer traditional more extensive farming landscapes over more modern intensive farming landscapes. Moreover, the results suggest that there are systematic differences in preferences for traditional farm landscapes between different demographic groupings and also depending on individuals’ environmental value orientations. Accordingly, in studying preferences for agricultural landscapes in particular areas it will be necessary to consider the social and demographic characteristics of the population as well as the physical aspects of the landscape.     

蔬菜质量安全可追溯系统的设计与实现

将网络信息技术与蔬菜种植业实际相结合,应用EAN·UCC条码为蔬菜产品标识,构建了一套蔬菜质量安全可追溯系统,实现对蔬菜产品质量的追溯管理。该系统为增强政府管理部门的监管手段和监管效率,提高生产企业生产管理水平,增加企业竞争力,增强消费者的安全感提供了技术保障。该系统已在深圳市实际应用。     

季节性冻土对风电场杆塔基础稳定性影响研究

本文分析了风电场架空输电线路的特点以及季节性冻土对线路基础的危害,并结合风电场中35 kV直流输电线路杆塔基础的稳定进行分析.计算结果表明,在季节性冻土地区,特别是对冻深较大的地区,在基础埋深达到要求的同时,切向冻胀力也会对基础的稳定造成不利影响.因此,对季节性冻土地区的输电线路基础工程除按一般地区的要求进行设计施工外...     

配电系统潮流计算中风电场节点的处理方法

20世纪80年代以来,风力发电在世界范围内得到了迅猛发展.并网运行的风电场对配电系统的电能质量,潮流与网损等都将产生一定影响.潮流计算是对这些影响进行评估的最基本手段.介绍了含风力发电的配电系统的确定性潮流计算及随机潮流计算中风电场节点的不同处理方法,并进行比较,得出各自的适用场合.     

风电机组通信模块软硬件设计

针对IEC61400-25明确提出风电机组的通信应基于制造报文规范通信协议,设计并实现一种基于IEC61400—25标准的风电机组通信模块。该模块采用ARM9＋JAVA＋MMS结构,通过提供IED配置、IED信息模型的重构、设备参数的读写等通信服务,以及对标准MMS通信协议风电场无缝通信的实现,可屏蔽风电机组的通信差异,有效解决一致通信问题,提高风电场通信的效率与可靠性。     

风电场风能资源评估几个关键问题分析

正确科学地对风资源进行评估,意义重大。针对我国风电场工程可行性研究报告的现状和GB/T 18709—2002《风电场风能资源测量方法》、GB/T 18710—2002《风电场风能资源评估方法》、《全国风能资源评价技术规定》等的某些条款进行了阐述,指出目前风资源评估中存在的一些问题并提出了一些建议,希望为以后的相关工作人员提供一个参考。     

Multiobjective optimization in combinatorial wind farms system integration and resistive SFCL using analytical hierarchy process

This paper presents a positive approach for low voltage ride-through (LVRT) improvement of the permanent magnet synchronous generator (PMSG) based on a large wind power plant (WPP) of 50 MW. The proposed method utilizes the conventional current control strategy to provide a reactive power requirement and retain the active power production during and after the fault for the grid codes compliance. Besides that, a resistive superconducting fault current limiter (RSFCL) as an additional self-healing support is applied outside the WPP to further increase the rated active power of the installation, thereby enhance the dc-link voltage smoothness, as well as the LVRT capability of the 50 MW WPP. This is achieved by limiting the exceed fault current and diminishing the voltage dip level, leading to increase the voltage safety margin of the LVRT curve. Furthermore, the effect of the installed RSFCL on the extreme load reduction is effectively demonstrated. A large WPP has a complicated structure using several components, and the inclusion of RSFCL composes this layout more problematic for optimal performance of the system. Hence, the most-widely decision-making technique based on the analytic hierarchy process (AHP) is proposed for the optimal design of the combinatorial RSFCL and 50 MW WPP to compute the three-dimensional alignment in Pareto front at the end of the optimization run. The numerical simulations verify effectiveness of the proposed approach, using the Pareto optimality concept.     

城市中心“农业生态建筑”解读

解读以建筑农场为代表的农业生态建筑的形成背景、类型特点及生态技术,分析城市环境、居民与农业建筑、自然资源之间构成的生态循环特征,探讨我国未来都市农业发展方向。