变负荷机组锅炉经济连续排污流量的确定

通过开展变负荷机组的热化学实验，监督不同负荷工况下的汽水品质，确定较为经济的锅炉连续排污流量，对产生的效益进行了分析和计算。     

Retention of Sediment and Nutrient Loads with Peak Runoff Control

The purpose of this research was to evaluate peak runoff control as a water protection method to reduce sediment and nutrient loads. Increased eutrophication of surface waters and risk of floods demands cost effective methods to reduce pollutant input and risks of flooding. With the peak runoff control it is possible to cut the main peaks and store the runoff water temporarily in ditches. The method decreases the suspended solids (SS) and nutrient loads by reducing flow velocities, and improving the settling of sediment particles. The method was tested in two heavily drained adjacent peat harvesting areas suffering considerable erosion. The peak flows were cut by 27–87%, the SS load by 61–94%, the total nitrogen (Ntot) by 45–91%, and the total phosphorus (Ptot) load by 47–88%. The peak runoff control method operated most effectively during extreme events when most of the SS load is transported. A detailed particle analysis of runoff water showed that water detention reduced the median particle size of SS load as the largest particles settle. The results clearly indicate that the peak runoff control is an effective method to control the sediment loads and peak flows from peatland drainage.     

Phosphorus Retention by Bioretention Mesocosms Using Media Formulated for Phosphorus Sorption: Response to Accelerated Loads

Recent research indicates that phosphorus (P) retention by bioretention systems comprising sandy media may not be effective for even a decade of urban runoff loads. To improve P retention for longer durations, this paper present findings from bioretention mesocosms using media amended with red mud (RM), a by-product of bauxite processing; water treatment residuals (WTRs), a by-product of water treatment; or Krasnozem soil (K), a highly aggregated clay soil. All treatments were vegetated except for one (K20nv). All treatments had outlets to restrict outflows except for one (WTR-Knr). To simulate the effect of long-term nutrient loads, the mesocosms were loaded weekly with secondary treated effluent with P concentrations averaging 3.3??mg-L-1. Over 80 weeks, this comprised hydraulic loads from 24.5 to 29.3??m-year-1 at a flow-weighted average between 2.8 and 3.2??mg-L-1 PO4-P, or mass loads from 1,115 to 1,284??kg-ha-1 PO4-P. These cumulative P loads represent the equivalent of over three decades of runoff loads. After 80 weeks, cumulative PO4-P retention in the K and RM soil treatments ranged from 79% to 95%, whereas PO4-P retention in the WTR treatments ranged from 95% to 99% of the input load. At 6-month intervals, the treatments were dosed with at least four sequential dosing runs of synthetic storm water with concentrations less than 0.8??mg-L-1 PO4-P. After 56 weeks of effluent loading, removal of PO4-P from storm water was negative 109% in the unvegetated K20nv treatment, compared with 33% retention in the corresponding vegetated K20 treatment. The K40 treatment with the most K retained 69% PO4-P, while the RM10 treatment with the most RM retained 78% PO4-P. After 80 weeks of effluent loading, removal of PO4-P from storm water was negative in both the K20nv and vegetated K20 treatments. The K40 treatment retained 76% PO4-P, and the RM10 treatment retained 55% PO4-P, while the total dissolved P (TDP) retention was 72% and 52%, respectively. After 110 weeks of effluent loading comprising 1,598??kg-ha-1 PO4-P, equivalent to 48?years of bioretention loads, PO4-P retention from storm water by the K40 treatment increased to 85%, and retention by the RM10 treatment increased to 91%. TDP retention also increased to 78% and 75%, respectively. These observations of P retention increasing after exposure to additional loads are uncharacteristic of typical sorption responses. After 80 weeks of effluent loading equivalent to 32?years of bioretention loads, the flow-restricted WTR-K treatment removed 99% of the storm-water PO4-P load while the corresponding free-discharge WTR-Knr treatment retained 94%. The WTR-K treatment was less effective than the WTR-Knr treatment in the earlier storm-water runs. The restricted outlet WTR30 treatment, which contained the most WTRs, retained 99% of the storm-water PO4-P load. These high rates of P retention from storm water after accelerated P loads indicate that these amendments can provide effective P retention for the expected lifetime of bioretention facilities.     

Decision Support System for Stakeholder Involvement

Stakeholder involvement is essential to the development of a total maximum daily load (TMDL) and its implementation plan. A tool, beyond a simulation model, is needed to support the decision making process that requires negotiation and compromise among stakeholders. The decision support system (DSS) described herein has a TMDL module to calculate various combinations of point and nonpoint loads that can meet the water quality criteria. Its Consensus module allows stakeholders to formulate, evaluate, modify, and vote for alternatives. The DSS displays bar charts for pollution loads from various subwatersheds and attributes the nonpoint loads to land uses. The water quality consequence of the pollution loads is output in maps, which shows sections meeting criteria in green and those not in red. The DSS requires a front end effort of site specific adaptation and model calibration. An Internet-based stakeholder process was developed to allow more concerned citizens to participate in management decisions.     

Rain Loads and Flow Attenuation on Roofs

Basic relationships are derived for calculating the flow attenuation and depth of storm water on roofs. Hyetographs and corresponding hydrographs are specialized to the case of roof drainage and incorporated in methods which are presented for analysis and design of roof drains. Roof storage and outflow are characterized for various roof geometries and outflow devices. The methods are applied to examples found in the literature, including those in standards of Factory Mutual Insurance Company, ASCE, and others. Assumptions implicit in those standards are tested and their limitations demonstrated. A critical duration at which the greatest water depth and outflow occur must be found on a case-by-case basis. The critical durations can differ significantly from the fixed durations specified in standards. The corresponding maximum water depths and peak outflows can also differ accordingly. For determination of roof loads, these results will have their greatest importance in warmer climates in which the rain loads govern over snow loads. An example of design specifically for flow attenuation is also presented.     

太钢4350m~3高炉稳定炉体热负荷的实践

针对太钢4350m~3高炉软水密闭循环冷却的特点,通过分析炉内煤气流分布Z值、W值对炉体各段热负荷的影响,炉腹煤气量、焦炭质量等对全炉热负荷的影响,总结了实现炉体热负荷的稳定性和可控化的操作经验。     

Utility of LANDSAT-Derived Land Use Data for Estimating Storm-Water Pollutant Loads in an Urbanizing Area

In many watersheds located in southern California, efforts are being focused on urban runoff because of its adverse impact on receiving water quality. The Sweetwater River watershed is a good example, where the drainage area is rapidly urbanizing and deteriorating reservoir water quality. Contaminated storm water is captured and diverted but as urbanization increases, additional runoff will be generated which will overload the existing infrastructure. To better manage the diversion systems and minimize future construction, storm-water volumes and pollutant loadings need to be estimated. Due to the lack of real-time storm-water runoff monitoring data, pollutant loadings must be estimated from land use information. We used satellite imagery to estimate selected storm-water pollutant loads and compared the results to predictions using land use information from public records. Satellite imagery was useful in estimating storm-water pollutant loads and identifying high loading areas. Satellite imagery with appropriate classification is a promising tool for watershed management and for prioritizing best management practices.     

Spurious Correlation in the USEPA Rating Curve Method for Estimating Pollutant Loads

Water quality models are important tools used for developing total maximum daily loads (TMDLs), which are used to implement water quality standards. The writers have developed a tool which spatially interpolates output from the Chesapeake Bay Program Watershed Model (WSM) and requires little time, data, or training. In contrast, the WSM requires extensive time, data, and training to run. This study examines if the writers’ tool provides accurate estimates of pollutant loads as compared to observed pollutant loads calculated using two different rating curve methods. The accuracy of the tool was assessed based on Nash–Sutcliffe coefficients. This study found that the tool provided moderate estimates of total nitrogen, poor estimates of total phosphorus, and that the rating curve method used to calculate observed loads affected the conclusion of the accuracy of the writers’ tool for predicting total sediment. A key finding of this study is that the widely used load-derived method for calculating observed loads exhibits spurious correlation. The writers discuss the imperative need to use sound statistical methods when estimating pollutant loads and TMDLs, and suggest an alternative approach for developing rating curves which is not subject to the problem of spurious correlation.     

Effects of gastric loads and food deprivation on subsequent food intake in suckling rats.

In 4 experiments, a total of 478 suckling Charles River rats were subjected to deprivation periods of 6-8 hrs. Intake following deprivation was greater in deprived than in nondeprived Ss but did not increase with increasing deprivation. Gastric loads of NaCl solutions depressed subsequent intake; 3% NaCl was more effective than .9% NaCl. Other gastric loads of varying osmotic and caloric values also depressed subsequent intake. In order of increasing effectiveness in depressing intake, the gastric loads were protein hydrolystate, heavy cream, water, milk, lactose, glucose, and corn oil. Effectiveness was unrelated to osmotic or caloric value of the load. Gastric fill and, possibly, some property of carbohydrate appeared to be important determinants of satiety in the S. (22 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Analysis of the Stability of I-Walls with Gaps between the I-Wall and the Levee Fill

Following Hurricane Katrina an extensive investigation of the performance of floodwalls in the New Orleans area was undertaken by the U. S. Army Corps of Engineers and others. This investigation included detailed study of failures of cantilevered sheet pile “I-walls” during the hurricane. An important lesson from this investigation was that gaps can form on the canal side of I-walls as the water rises in the canal and causes the I-wall to deflect. Once formed, these gaps filled with water, resulting in significantly higher loads on the walls. Gap formation was a key factor in several I-wall failures, and modeling such gaps correctly is clearly an important aspect of analyzing I-wall stability. This paper describes simple procedures for estimating the depths of gaps behind I-walls, for calculating the loads to which they are subjected, and for including them in stability analyses. The effects of gaps on the stability of the 17th Canal and the London Avenue Canal I-walls are discussed.     

Estimating Nonpoint Source Pollution in the Upper Yangtze River Using the Export Coefficient Model, Remote Sensing, and Geographical Information System

Recently, increasing nutrient (i.e., nitrogen and phosphorus) concentrations have been observed in the surface water of many countries and this nonpoint source (NPS) pollution has become an important factor in the deterioration of water quality in the upper reach of the Yangtze River Basin. In this paper, the NPS pollution loads in the upper reach of Yangtze River Basin in the year 2000 were estimated using export coefficient model and remote sensing techniques. The spatial distributions of the NPS loads within the watershed were then displayed using geographical information system. Results indicated that the total nitrogen load was 1.947×106?t and the total phosphorus load was 8.364×104?t. Important source areas for the nutrients were croplands in the Jinsha R. and Jialing R. watershed, as well as the Chongqing municipality.     

浅谈变频调速装置在风机及水泵中的应用

某公司为降低成本,节能降耗,对负载变化较大的风机、水泵引进变频调速技术,通过调节风机、水泵的转速来调节其提供的风量、流量,取得了良好的节能效果。     

株冶废水中和工艺改进探讨

本文简介株洲冶炼厂废水处理厂工艺和现状，分析了现有石灰中和法一段中和工艺和设备难以应付废水跑酸跑液冲击负荷的原因。提出利用现工艺配置均化池，在跑酸跑液时进行预中和的改良二段中和工艺。     

Surface Analysis of Chesapeake Bay Water Quality Response to Different Nutrient and Sediment Loads

Based on a set of Chesapeake Bay Estuarine Model (CBEM) scenarios, a three-dimensional response surface of a water quality index, such as chlorophyll concentration, versus a pair of loading constituents, e.g., nitrogen and phosphorus, is constructed. The responses of water quality, such as dissolved oxygen, chlorophyll, and water clarity, to nitrogen, phosphorus, and sediment loads are analyzed. From the response surface, a water quality response is estimated under loading conditions beyond that of a limited set of scenarios. Response surfaces may be used to determine the possible universe of nutrient and sediment load reductions needed to obtain a particular water quality standard and to examine the tradeoffs among nutrient and sediment load reductions that achieve the same water quality objective.     

Effects of Long-Term Dynamic Loading and Fluctuating Water Table on Helical Anchor Performance for Small Wind Tower Foundations

The application of this study is to use helical anchors as a foundation system for small wind tower (1–10?kW) guyed cables. Helical anchors are currently used to anchor guyed cables of cell or transmission towers. However, the increased dynamic vibrations a wind turbine adds to the tower and foundation system under working loads, as well as extreme environmental conditions (e.g., straight line winds, ice load, or sudden furling shocks), require additional knowledge about the behavior of helical anchors. These field conditions were simulated in this study from tower-instrumented field data on wind speed and tower response. These tower responses were then transmitted to the helical anchors through an extensive, large-scale testing program that included monitoring the performance of the helical anchor foundation under dynamic loads, subject to natural variations in both wind regimes, precipitation (water level) and variations in helical anchor geometry. This paper compares the uplift prediction methods used in helical anchor design as well as discusses the effects of long-term dynamic loading and fluctuating water table on helical anchor performance.     

Spatial-Dynamic Modeling of Algal Biomass in Lake Erie: Relative Impacts of Dreissenid Mussels and Nutrient Loads

Over the past several decades, reductions in phytoplankton stocks and increased water clarity in Lake Erie have resulted from phosphorus load abatement and the introduction of zebra (Dreissena polymorpha) and quagga mussels (D. bugensis). The relative impacts of these developments and their implications for lake management have remained difficult to delineate. To address this issue, we numerically model the complex biophysical interactions occurring in Lake Erie using a two-dimensional hydrodynamic and water quality model that is extended to include dreissenid mussel and zooplankton algorithms. The model reasonably simulates longitudinal trends in water quality as well as the dynamics of central basin hypoxia. Phosphorus is the limiting nutrient through the euphotic zone and its control decreases the algal growth rate and biomass ( ～ 55–60%). Filter feeding by dreissenid mussels also decreases algal biomass ( ～ 25–30%), simultaneously stimulating increased net algae growth through enhanced algal consumption and subsequent phosphorus recycling. Effective recycling implies that algae stocks are ultimately regulated by external phosphorus loads. Returning phosphorus loads to pre-abatement 1960s levels, in the presence of dreissenid mussels, results in a western basin algae concentration of ～ 0.7?mg?dry?weight?L?1 with a potential for nuisance algae growth.     

Wave Diffraction by a Vertical Cylinder with a Porous Ring Plate

Linearized potential wave theory is applied to investigate the phenomenon of wave diffraction by a vertical circular cylinder with a thin ring plate in water of finite depth. By means of the eigenfunction expansion method, harmonic expressions for the velocity potential are obtained. The numerical results for the wave loads and the wave height surrounding the body are discussed. It is found that the presence of a thin ring plate causes the focusing of wave energy near the rear edge of the cylinder for small dimensionless porous-effect parameters. A porous ring plate behaves as a wave absorber, which leads to a decrease of the wave height until setdown occurs. The ring plate can decrease not only the horizontal wave force but also the moment on the cylinder. In general, the mechanism of decreasing the wave loads on the cylinder by a porous ring plate is different from that by an impermeable ring plate. An impermeable ring plate attached to the cylinder causes wave focusing near the rear edge of the cylinder so that the difference between wave heights at the front edge and at the rear edge of the cylinder becomes small; hence the wave loads on the cylinder are decreased. A porous ring plate behaves as a wave absorber, which decreases the wave height at the front edge of the cylinder, and thus leads to a decrease of wave loads on the cylinder.     

Hydrologic and Water Quality Integration Tool: HydroWAMIT

A spatially distributed and continuous hydrologic model focusing on total maximum daily load (TMDL) projects was developed. Hydrologic models frequently used for TMDLs such as the hydrologic simulation program—FORTRAN (HSPF), soil and water assessment tool (SWAT), and generalized watershed loading function (GWLF) differ considerably in terms of spatial resolution, simulated processes, and linkage flexibility to external water quality models. The requirement of using an external water quality model for simulating specific processes is not uncommon. In addition, the scale of the watershed and water quality modeling, and the need for a robust and cost-effective modeling framework justify the development of alternative watershed modeling tools for TMDLs. The hydrologic and water quality integration tool (HydroWAMIT) is a spatially distributed and continuous time model that incorporates some of the features of GWLF and HSPF to provide a robust modeling structure for TMDL projects. HydroWAMIT operates within the WAMIT structure, developed by Omni Environmental LLC for the Passaic River TMDL in N. J. HydroWAMIT is divided into some basic components: the hydrologic component, responsible for the simulation of surface flow and baseflow from subwatersheds; the nonpoint-source (NPS) component, responsible for the calculation of the subwatershed NPS loads; and the linkage component, responsible for linking the flows and loads from HydroWAMIT to the water quality analysis simulation program (WASP). HydroWAMIT operates with the diffusion analogy flow model for flow routing. HydroWAMIT provides surface runoff, baseflow and associated loads as outputs for a daily timestep, and is relatively easy to calibrate compared to hydrologic models like HSPF. HydroWAMIT assumes that the soil profile is divided into saturated and unsaturated layers. The water available in the unsaturated layer directly affects the surface runoff from pervious areas. Surface runoff from impervious areas is calculated separately according to precipitation and the impervious fractions of the watershed. Baseflow is given by a linear function of the available water in the saturated zone. The utility of HydroWAMIT is illustrated for the North Branch and South Branch Raritan River Watershed (NSBRW) in New Jersey. The model was calibrated, validated, and linked to the WASP. The NPS component was tested for total dissolved solids. Available weather data and point-source discharges were used to prepare the meteorological and flow inputs for the model. Digital land use, soil type datasets, and digital elevation models were used for determining input data parameters and model segmentation. HydroWAMIT was successfully calibrated and validated for monthly and daily flows for the NSBRW outlet. The model statistics obtained using HydroWAMIT are comparable with statistics of HSPF and SWAT applications for medium and large drainage areas. The results show that HydroWAMIT is a feasible alternative to HSPF and SWAT, especially for large-scale TMDLs that require particular processes for water quality simulation and minor hydrologic model calibration effort.     

地震时作用于深水桥墩上的动水力及对桥墩动力响应的影响

基于势流体理论,针对一典型实体矩形截面桥墩,分析了不同水深时,动水对桥墩自振特性的影响.研究了不同水深和地震波类型等条件下,作用于桥墩上动水压力的分布规律及其合力作用点位置,并分析了动水对矩形截面桥墩在地震作用下动力响应的影响.结果表明,由于动水和结构相互作用的影响,矩形截面桥墩的自振周期、墩底弯矩及剪力的峰值会随着水深的增加而不断增大.动水使墩底弯矩和剪力分别最多增大了31%和50%,因此动水对桥墩动力反应的影响不可忽略.并且,不同类型地震波对作用于桥墩上的动水压力分布的影响也不相同.根据日本规范计算作用于矩形截面桥墩上的动水力的结果与本文的结果更为接近.     

Erosion resistance of some antifriction materials intended for operation in water

Conclusions In light of the investigation described in can be concluded that bronze infiltrated with PTFE holds considerable promise for operation under conditions of lubrication with hot water and without lubricant, since it possesses both high erosion resistance and good antifriction properties. It can be used, in combination with chromized surfaces, for bearings and seals in rubbing units of pumps and turbines operating at sliding speeds of up to 50 m/sec (15,000 rpm), loads of up to 2 kg/cm², lubricating water temperatures of up to 110°C, and water pressures of up to 20 atm.Translated from Poroshkovaya Metallurgiya, No. 11(155), pp. 82–86, November, 1975.