京津唐电网进一步开发抽水蓄能电站的时序分析

京津唐电网为火主电网,电网电源结构单一,随着电网负荷及负荷峰谷差的增加,调峰容量严重不足,为满足电网调峰需求及改善电网电源结构,需建设一定容量的抽水蓄能电站,为此,就距负荷中心较近,开展工作较多的丰宁,板桥峪,桃花寺三座抽水蓄能电站进行比较分析,提出一较为合理,可行的蓄能电站开发时序及意见供参考。     

农村供水消毒设备运行管理与检测评价方法

饮用水消毒是供水工程必不可少的重要环节,是保证供水安全的最后一道屏障。在正确选择消毒技术和设备的基础上,消毒设备正常运行对保证饮用水消毒合格十分重要。在简要介绍了4种农村供水常用消毒设备组成和原理的基础上,根据全国6个省的6个县100多处农村供水消毒技术示范工程运行管理与监测评价经验,总结形成了适合农村供水特点的消毒设备运行操作方法及环境条件要求,提出了消毒效果评价指标、检测方法和频率,以期实现农村供水消毒设备正常运行和消毒效果达标。     

Analysis of the temperature and icing regimes of pipelines under severe climatic conditions

Temperature and icing regimes are presented for conduit operation. Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 4, June 2008, pp. 38–40.     

高地温引水隧洞围岩热——应力耦合分析

针对新疆某高地温环境下的圆形隧洞,采用有限元分析程序,分别对不同围岩半径下的温度场分布进行模拟,并以不同围岩半径下围岩与支护接触面处的温度作为围岩合理计算范围取值的参考,结合有关理论分析的结果,确定出围岩最佳计算半径。在此基础上进一步研究隧洞施工期围岩温度、应力和位移场在热—应力耦合作用下的分布问题。研究结果表明,当围岩外部温度为80℃、隧洞内部温度为5℃时,隧洞开挖后考虑温度和应力共同影响下的围岩最佳计算半径为24 m。隧洞围岩温度沿围岩厚度方向呈非线性递增变化。与常温(20℃)情况相比,高地温的存在会使隧洞围岩最大主应力减小,同时也会在隧洞拱顶和底拱处产生拉应力。     

Hydraulic and pollutant removal performance of stormwater filters under variable wetting and drying regimes.

Biofiltration systems are an effective stormwater treatment technology. However, their robustness is yet to be tested, particularly their performance following extended dry periods. The hydraulic and treatment performance of five different non-vegetated, soil-based filters under varying periods of inundation and drying was assessed. The infiltration capacity of the filters decreased during wet periods and increased following dry periods, most probably due to swelling and shrinkage of the filter media. Treatment of sediment, heavy metals and phosphorus was not influenced by the wetting and drying regime. However, outflow concentrations of nitrogen were significantly higher upon re-wetting following extended dry periods compared with wet periods. This result has implications for current design practices, as these nitrogen pulses could negatively impact the ecological health of downstream receiving waters.     

Ambient odour testing of concentrated animal feeding operations using field and laboratory olfactometers.

The Missouri Air Conservation Commission regulations include regulations that limit the amount of acceptable odor from confined animal feeding operations (CAFOs). The regulations concerning odor designate the use of a scentometer as a screening tool. The rules dictate that if an odor is detectable by an investigator at a dilution ratio of 5.4 using a scentometer then an air sample should be collected and sent to an olfactometry laboratory for an odor panel to determine the detection threshold and the intensity of the odor sample. The detection thresholds are determined following ASTM E679-91 and EN13725. The intensity is determined following ASTM E544-99. If the olfactometry laboratory determined the detection threshold of the sample to be above seven, then the CAFO would be in violation. If the olfactometry laboratory determined the intensity level to be above a level equivalent to 225 ppm of n-butanol, then the source of odor would be in violation. The CAFO odor rules came under scrutiny by representatives of the largest hog producer in the State of Missouri. Specifically, they argued that the detection threshold limit of seven in the CAFO portion of the rule was too low for the rule to realistically identify a violation. This paper presents the results of a study to find the appropriate regulatory level of odor as determined by laboratory olfactometry. The study took place from November 2001 to October 2002. Samples were collected from field locations that exhibited odor produced by confined animal feeding operations and from areas exhibiting no apparent odor. The odors were categorized based upon the scentometer level at which the odors were detectable, and then samples were sent to an odor evaluation laboratory for analysis by olfactometry.     

The assessment of different operating strategies for minimising activated sludge deflocculation under temperature transient conditions.

Three operating strategies were tested for decreasing activated sludge deflocculation due to temperature shifts from 30 degrees to 45 degrees C: magnesium sludge enrichment, increased sludge retention time (33 d), and spikes of an easily degradable substrate (methanol). The temperature shifts were conducted sequentially in 4 parallel lab-scale sequencing batch reactors (SBRs) treating kraft pulp mill effluent. Three SBRs operated at an SRT = 20 days, and in one of them the sludge was not manipulated, thus, serving as a reference SBR. The temperature shift was associated with decreased soluble chemical oxygen demand (SCOD) removals, decreased sludge settleability and substrate removal capacity, and increased effluent suspended solids (ESS) and turbidity levels. The shift also increased the sludge specific respiration rates and reduced the sludge substrate removal capacity. Sludge deflocculation was assessed as floc solubilisation (increased effluent SCOD levels) and floc fragmentation (increase in effluent solids smaller than 50 microm). Mg enrichment of the sludge and methanol spikes reduced the ESS levels (in 9 and 25%), and the three operating strategies decreased effluent turbidity (in 22-35%) compared to the maximum levels from the non-manipulated reactor (44 mg ESS/L). The stronger sludge floc structure achieved by magnesium enrichment and a high sludge age of 33 days was unsuccessful in significantly decreasing deflocculation. The mechanisms involved in sludge deflocculation require further fundamental research.     

水下高围压磨料射流装置及冲蚀性能的研究

提出了水下高围压磨料射流切割模拟试验装置并对其进行了试验,得到了冲蚀深度与靶距,模拟水深,射流管长度及冲蚀时间的关系。同时对空气中磨料射流与纯水射流的冲蚀性能也进行了比较,本文较全面地揭示了水下磨料射流的冲蚀性能,为实际应用提供了必要的依据。     

高地温引水隧洞隔热支护结构温度及应力特性分析

以解决高地温特殊环境下引水隧洞支护结构隔热保温问题及优化支护结构设计为目标,研究高地温引水隧洞不同隔热支护结构聚苯乙烯泡沫聚苯板(EPS)、聚苯乙烯泡沫挤塑板(XPS)的温度分布规律及受力特性,以新疆某水电站引水隧洞为研究对象,基于隧洞现场监测试验成果,采用有限元软件对支护结构的温度场和应力场进行模拟。结果表明:采用隔热层能减少温度对围岩和支护结构温度分布的影响;高地温隔热支护结构中隔热选材必须具有良好的保温隔热性能和一定的强度;EPS板两侧温差比XPS板两侧温差大2.11℃;相较XPS复合衬砌和普通混凝土衬砌, EPS复合衬砌内外温差最小,EPS复合支护结构隔热性能最好;三种衬砌结构拱顶处环向应力均最大,相比之下EPS复合衬砌环向应力最小,其值为0.40 MPa,EPS复合支护结构受力特性最好。对比分析结果表明,支护结构隔热选材上EPS板性能优于XPS板。     

泵站进水流道混凝土施工期温控防裂研究

大型泵站流道部分结构复杂且厚薄不均,其施工期混凝土开裂问题尤为突出.结合南水北调洪泽泵站工程,借助于有限单元法,对高温季节浇筑的泵站肘形进水流道混凝土施工期的温度场及应力场进行了动态仿真,在分析进水流道的易裂部位和开裂机理的基础上,提出有效防裂措施,包括控制浇筑温度在28℃以内,同时采用塑料管冷却及拆模后的表面保温措施.现场实际施工结果表明:仿真结果合理、防裂方法有效可行.     

高地温隧洞喷射混凝土粘结强度及其有限元分析

针对在高地温隧洞中喷射混凝土和岩壁间粘结强度的问题,采用模拟现场试验的方法,对不同温度的岩板喷射混凝土,在恒定的温度下养护28 d龄期,通过钻芯拉拔试验测得喷射混凝土与岩板的粘结强度。再对混凝土岩板进行模拟隧洞过水试验,过水完成后再次测定混凝土与岩板的粘结强度,最后利用大型有限元软件ANSYS对混凝土岩板温度场进行模拟,得出相应的应力分布与试验结果进行对比。结果表明:过水前,喷射混凝土与岩板间的粘结强度随着温度升高而降低;过水后,随着温度逐渐升高,喷射混凝土与岩板的粘结强度降低幅度逐渐增大。     

贝叶斯框架下的大坝变形交互式时变预测模型及其验证

大坝变形是同一时刻内外多重风险因素综合作用的结果,应用时序分析方法挖掘历史监测数据潜在规律是变形预测的常用方法,现有时变预测模型不仅参数配置难度高,且难以融入专业知识,导致预测效果并不理想。本文提出一种耦合自动预测算法与大坝专业知识的交互式变形预测模型。该模型在贝叶斯框架下,以加法模型为基础重构各时序分解项作为模型底层,根据仿真结果甄选模型参数缺省值进行自动预测,通过结合参数化检测与直观参数配置实现交互式建模,并借助拟合可视化和统计指标准确反映预测误差来源,从而进一步修正参数以提高模型适用性。基于上述流程协同构建的大坝变形循环预测体系,以某混凝土坝多测点长期变形监测数据为例,对模型的准确性、鲁棒性和灵活性进行了有效验证与分析,为大坝变形安全预测与分析提供了新的模型和手段。     

柳河流域降水量时空变化分析

柳河是辽河下游右岸一级支流,是一条多沙河流。通过对流域降雨地区分布、年内变化、年际变化规律研究分析,对流域治理和生态恢复提供依据。     

北京市节水灌溉管材及设备应用现状和质量控制措施分析

通过对北京市农业节水灌溉管材及设备应用现状进行调研,从节水增效、最大限度发挥设备作用等角度出发,分析了北京市农业节水灌溉管材及设备应用现状和存在的问题。结合北京市农业节水灌溉实际情况及发展需求,从设计、评审、招标采购、施工、管护等各个环节提出了加强主要节水灌溉管材与设备质量控制和监管措施的具体对策建议。     

Analysis of sulfur and nitrogen odorants using solid-phase microextraction and GC-MS.

An analytical method involving solid-phase micro-extraction (SPME) and gas chromatography-mass spectrometry (GC-MS) was applied to analyze biosolids odors. A selective ion monitoring (SIM)-based MS method was developed, using SPME injections of odorant standards under the full-scan mode to select the quantification and confirmation ions for each odorant. The odorants analyzed in this study include: dimethylsulfide, dimethyldisulfide, methyl mercaptan, hydrogen sulfide, carbon disulfide, trimethylamine and dimethylamine. We have used this method to quantify parts-per-billion levels of odorant vapors produced during anaerobic incubation of digested wastewater sludge. Important considerations for expedient and accurate calibration under static and dynamic flow conditions are discussed. The SPME-GC-MS method may give a positive intercept in the calibration curve, especially under static sampling conditions, which sets a practical detection limit for odor analysis.     

常温厌氧生物滤池处理生活污水原理与技术

介绍厌氧生物处理的基本原理、温度对厌氧处理的影响和厌氧生物滤池处理技术的特点,综述了国内常温厌氧生物滤池处理生活污水技术的研究成果.为了解决常温厌氧生物滤池脱氮除磷效率低、出水N、P浓度高的问题,提出常温厌氧生物滤池组合人工湿地或人工土地渗滤处理工艺的设想,在不曝气的条件下,满足高标准的出水需求,降低能耗.     

迪那河五一水库水温预测分析研究

对迪那河五一水库水温结构类型进行判别,用经验公式法对水库水温及下泄水温进行预测,并对其进行分析。结果表明:水库各月的月平均水温在45m水深以下,水温保持不变,在0―45m水深范围水温变化有所不同;水库下泄水温在4月至10月恒为7.5℃,比月平均水温略低,但要低于河道水温。水库对水温有一定的调节作用,在外界气温高的阶段能抑制水温的升高,相反能抑制水温的降低。迪那河汛期时的河流泥沙及水库运行方式对水库中底层水温及下泄水温有一定的增温作用。     

温州市大中型水库防洪功能发挥制约因素及应对措施分析

温州市地理位置特殊,台风、洪涝灾害频发,防汛压力较大。通过分析影响温州市大中型水库防洪功能正常发挥的主要制约因素,提出了具体的应对措施,可为类似地区水利工程管理者提供参考借鉴。