燃煤电厂优化用水及水污染防治工程改造方案的探讨

目前很多燃煤电厂为了提高经济效益,对厂内的各类废水进行梯级利用,以达到优化节水的目的,达到经济效益的同时亦能体现社会责任。燃煤电厂运行系统复杂,各个工区及生活区都会产生各类废水,对这些废水进行处理即可以重复利用。经对厂内的各类废水进行梯级利用后,可以有效减少水源取水需求量及污水排放量,实现节水减排目的。本文针对广西某燃煤电厂优化用水及水污染防治工程改造方案进行探讨,以期为以后此类项目提供参考。

大型火电厂全厂水平衡试验与深度优化用水分析

根据GB/T 12452—2008《企业水平衡测试通则》、DL/T 606.5—2009《火力发电厂能量平衡导则第5部分:水平衡试验》、DL/T 783—2018《火力发电厂节水导则》等,对一大型复杂火电厂(310 MW煤机+330 MW煤机+2×390 MW燃机+2×660 MW煤机)的全厂取水、用水、排水状况进行调查和水平衡试验,明确了各用水系统的现状和存在的问题,并对现有的用水状况进行评价,提出了电厂深度优化用水方案和节约用水的合理建议,预期节水效果较为明显。

基于全厂水平衡试验的燃煤电厂深度优化用水分析

根据《火力发电厂水务管理导则》(DL/T 1337-2014)、《火力发电厂能量平衡导则》(DL/T 606.5-2009)第5部分:水平衡试验,要求,对某燃煤电厂2×145 MW+2×335 MW机组进行全厂水平衡试验,掌握了全厂及各子系统的取水、用水、排水现状,对现有水量数据及用水指标进行分析评价,提出了电厂深度优化用水方案,预期节水效果较为明显。

火力发电厂水系统深度优化技术的实践

通过对水系统中取水、用水和排水设施的技术改造,江苏华电扬州发电有限公司将迈进节水型火力发电企业行列。对本企业发电过程中水系统设备技术升级,提高了原水预处理能力、锅炉补给水精度以及循环水工业水的利用率,并通过整合生活污水、渣水、含煤废水、脱硫废水等处理系统,实行梯级利用,实现废水零排放,最大限度地利用水资源,发电水耗率由1.75 m^(3)/MW·h之上降低到1.71 m^(3)/MW·h以下,达到节水型企业标准,年节约水费80余万元。这种在对水系统综合性分析基础上的深度优化技术运用,对于水系统不合理尤其是水资源利用不科学的火力发电厂具有积极的指导作用,对节能环保工作的开展亦具有很大的参考价值。

海水直流冷却机组全厂废水零排放技术优化选择

以海水直流电厂为对象,探讨了电厂优化用水的主要方案,通过废水分级分质回用大幅减少末端废水处理量,同时对目前常用的末端废水浓缩固化技术方案进行了技术经济比较。

DSF-GWO算法在玛纳斯河灌区种植结构优化中的应用

针对水资源总量约束条件下玛纳斯河灌区种植结构优化和农业用水合理配置的科学问题,以玛纳斯河灌区(石河子灌区、莫索湾灌区和下野地灌区)小麦、棉花、玉米、葡萄4种典型作物种植结构为基础,构建多目标优化配置模型对作物种植结构进行优化调整,采用改进后的灰狼优化算法(DSF-GWO)求解社会满足型(方案1)、节水优先型(方案2)、经济成本型(方案3)、综合发展型(方案4)4种发展情景下的子灌区农业种植结构优化方案.结果表明:石河子灌区方案2和方案3产生相同经济效益时,方案3的生态、社会效益比方案2分别低4.3%和7.3%,因此,方案2较适合石河子灌区规划年种植结构发展要求;莫索湾灌区方案4产生的经济效益分别高于方案1和方案3的3.6%和4.2%,生态效益高于方案2的0.5%,因此,选择方案4符合莫索湾灌区规划年种植结构发展需求;下野地灌区方案4产生的经济、社会效益均高于其他方案,生态效益对比其他方案相差较小,所以选择方案4对下野地灌区规划年种植结构进行调整.

Optimal rotor wear design in hypotrochoidal gear pump using genetic algorithm

The wear rate between the rotors of a hypotrochoidal gear pump is characterized.Using the knowledge of shape design on the rotors,the contact stresses without hydrodynamic effect between the rotor teeth were evaluated through the calculation of the Hertzian contact stress.Based on the above results and the sliding velocity between the rotors,a genetic algorithm (GA) was used as an optimization technique forminimizing the wear rate proportional factor (WRPF).The result shows that the wear rate or the WRPF can be reduced considerably,e.g.approximately 12.8%,throughout the optimization using GA.

Application Research of Oil Development Costs in Reservoir Management

Based on oil development costs, the application research in the technical and economic limits calculation of oil development and the production optimal allocation to all the oilfields, was finished. At the same time, according to the regression of real development costs, a new method for oil well economic water cut and oil well economic rate are set up, the production optimal allocation is developed with satisfactory results.

Application of experimental design in optimization of crude oil adsorption from saline waste water using raw bagasse

Experimental design was applied in the optimization of crude oil adsorption from saline waste water using raw bagasse.The application of response surface methodology(RSM) was presented with temperature,salinity of water,pH,adsorbent dose,and initial oil content as factors.A quadratic model could be used to approximate the mathematical relationship of crude oil removal on the five significant independent variables.Predicted values and experimental values are found to be in good agreement with R2 of 97.44%.The result of optimization shows that the maximum crude oil removal is equal to 67.38% under the optimal condition of temperature of 46.53 °C,salinity of 37.2 g/L,pH of 3,adsorbent dose of 9 g/L and initial oil content of 300×10-6.

Cr(Ⅲ) removal from simulated solution using hydrous magnesium oxide coated fly ash： Optimization by response surface methodology (RSM)

Hydrous magnesium oxide coated fly ash （MFA） has environmental remediation potential by providing a sub- strate for the adsorption of aqueous Cr（Ⅲ）. Aqueous Cr（Ⅲ） adsorption onto MFA was examined as a function of MFA dosage, pH and initial Cr（Ⅲ） concentration with the Box-Behnken approach used for experimental design and optimization using response surface methodology （RSM）. pH and dosage （dosage and concentration） have significant interactive effects on Cr（Ⅲ） adsorption efficiency. Analysis of variance shows that the response surface quadratic model is highly significant and can effectively predict the experimental outcomes. Cr（Ⅲ） removal effi- ciency of 98% was obtained using optimized conditions of MFA dosage, pH and initial Cr（Ⅲ） concentration of 1,5 7 g. L- 1, 4.11 and 126 mg. L- 1, respectively. Cr（Ⅲ） adsorption onto MFA is mainly attributed to the interaction between Or（Ⅲ） and the functional group --OH of the hydrous magnesium oxide, in all probability caused by chemisorptions. The results of this study can conduce to reveal the interactions between Cr（Ⅲ） pollutant and MFA characteristics, posing important implications for the cost-effective alternative adsorption technology in the treatment of heavy metal containing wastewater.

Energy and Water Optimization in Biofuel Plants

In this paper we address the topic of energy and water optimization in the production of bioethanol from corn and switchgrass. We show that in order for these manufacturing processes to be attractive,there is a need to go beyond traditional heat integration and water recycling techniques. Thus,we propose a strategy based on mathe-matical programming techniques to model and optimize the structure of the processes,and perform heat integration including the use of multi-effect distillation columns and integrated water networks to show that the energy effi-ciency and water consumption in bioethanol plants can be significantly improved. Specifically,under some circum-stances energy can even be produced and the water consumption can be reduced below the values required for the production of gasoline.

Production Benefits of Double-Cropping Rice Under Optimized Application of Nitrogen and Potassium Fertilizers Combined with Chinese Milk Vetch and Straw Co-Returning to Fields

In order to explore the technology and effects of reducing nitrogen and potassium fertilizer applications in double-cropping rice,a field plot experiment was conducted to study the effects of optimized application of nitrogen and potassium fertilizers combined with returning Chinese milk vetch and straw to fields on yield,fertilizer utilization efficiency,net photosynthetic rate(Pn),stomatal conductance(Gs),intercellular CO_(2) concentration(Ci),chlorophyll content(SPAD value)and soil physical and chemical properties in late rice harvest period.The results showed that the optimized application of nitrogen and potassium fertilizers combined with the integrated technology of Chinese milk vetch and straw co-returning to the field could enhance the photosynthetic efficiency of double-cropping rice,increase rice yield,and enhance soil biological activity,especially T4 treatment involving the returning of Chinese milk vetch and straw to the field instead of 30%nitrogen fertilizer achieved the highest rice yield,fertilizer use efficiency,net photosynthetic rate and soil biological activity.Compared with the conventional fertilization treatment T2,the total rice yield of T4 treatment increased by 4.1%,among which the early rice and late rice increased by 6.3%and 2.4%,respectively;Pn,Gs and SPAD values of flag leaves at full heading stage significantly increased,and the contents of soil active organic carbon,alkali hydrolyzed nitrogen,available phosphorus and readily available potassium significantly increased.

State Space Approach to Mass Exchange Network Synthesis

State space approach is an effective method to mass-exchange network (MEN) synthesis. By decomposing the network into two interactive parts, a distribution network and a process operator, the synthesis problem can be formulated into a mixed integer nonlinear programming (MINLP) model. In this article, a generalized state space model based on typical MEN is established and verified in two cases. A new asymmetrical operator and cost index are also adopted to speed up the solution process. The results demonstrate the efficiency of the proposed approach.

Application of genetic algorithm for influent flow distribution in the four stage A/O biological nutrient removal system

The application of the Genetic Algorithm （GA） for the influent flow optimized distribution in the four stage pilot plant of Step-Feed Biological Nutrient Removal （BNR） System was discussed. Under decided process parameter and influent water conditions, the objective function of optimization was designed to minimize the difference between estimated and required effluent concentrations at the four stage pilot plant of Step-Feed BNR System, the optimized parameter for influent distribution ratios of the four stages is 37.2%, 27.4%, 23.2% and 12.2% respectively. According to the optimizations results and raw wastewater pilot-scale experiment, the average removal efficiencies for pollutants are higher.

A stepwise optimal design of water network

In order to take full advantage of regeneration process to reduce fresh water consumption and avoid the accumulation of trace contaminants, regeneration reuse and regeneration recycle should be distinctive. A stepwise optimal design for water network is developed to simplify solution procedures for the formulated MINLP problem. In this paper, a feasible water reuse network framework is generated. Some heuristic rules from water reuse network are used to guide the placement of regeneration process. Then the outlet stream of regeneration process is considered as new water source. Regeneration reuse network structure is obtained through an iterative optimal procedure by taking the insights from reuse water network structure. Furthermore, regeneration recycle is only utilized to eliminate fresh water usage for processes in which regeneration reuse is impossible. Compared with the results obtained by relevant researches for the same example, the present method not only provides an appropriate regeneration reuse water network with minimum fresh water and regenerated water flow rate but also suggests a water network involving regeneration recycle with minimum recycle water flow rate. The design can utilize reuse, regeneration reuse and regeneration recycle step by step with minor water network structure change to achieve better flexibility. It can satisfy different demands for new plants and modernization of existing plants.

Research on optimal design of wastewater reclamation and reuse for a university

An optimal design of wastewater reuse for a University is concerned in this paper. The raw water and the capacity of wastewater reuse were determined according to the wastewater characteristic of a university; the treatment process was chosen by building a cost-benefit model; and the modeling test was performed about the operation effect of the proposed project and the recommended water quality of reclaimed water. It is estimated that 3.4×10^5 m^3/a tap water and 6.1×10^5 Yuan/a will be saved if the project was put into operation and the proposed project will reduce the total quantity of pollutant efficiently and bring lots of social and economic benefits.

某铝业水平衡测试分析

水平衡测试是加强用水科学管理,最大限度地节约用水和合理用水的一项基础工作,是在查清单位给排水管网基础上,所有供用和排水设施的各种水量通过计量仪表,按照一定的规程和方法进行测试。涉及到用水单位管理的各个方面,同时也表现出较强的综合性、技术性。通过测试、计算、分析有效利用水量和损耗水量,明确节水潜力,找出优化用水的途径,以提高单位用水的经济效益。