潜水推流器对龙景湖湖湾死水区水质影响试验研究

发布时间：2018-02-04 04:29

本文关键词： 湖泊死水区潜水推流器流速水质改善　出处：《重庆大学》2015年硕士论文　论文类型：学位论文

【摘要】：龙景湖湖面分布极不规则,形似掌状,除湖心区域较为宽阔外,还分布着大小不一的分岔湖湾,多数湖湾水流缓慢,流动性差,多为静止封闭缓流水体。用多普勒仪器对龙景湖各湖湾进行流速监测,通过EFDC软件对各监测点的断面进行流速绘制,通过对比最终将设备安放点选择在凌云桥靠近土坝一侧的湖湾,该处水流缓慢,初始水质较差,且适合设备安装,可以较好的反应潜水推流器的工作效果。通过参考大量文献,确定了潜水推流器选型的重要依据。对潜水推流器选型进行研究,结合湖湾现状的地形条件及水质情况,最后确定潜水推流器各参数为叶轮直径620mm,功率5kw,额定电流12A,转速480r/min,轴向推力1300N,重量184Kg。课题组采用浮筒形式安装潜水推流器。水深在0.5m~3m的范围内浮游植物的生物量最集中,推流器安装深度选择在水下2.0m处。课题组选取0.10m/s的流速作为潜水推流器所推送水体达到的流速限值,也将其作为推流器工作的有效范围界定条件。通过潜水推流器的运行,探求其运行效果对湖湾水质条件影响情况。论文主要研究结论如下:①对不同水深(表层,2m,4m)的各取样点的监测,位于1-2#点的流速最大,达到0.619m/s,而处于2m处水深的流速较其他水深的流速大,说明潜水推流器在水深2m处的影响最大,效果最好。1m处水深的流速也比较大,1-1#,2-1#点的流速分别为0.488m/s,0.489m/s,说明潜水推流器的作用范围在水深1~2m处影响明显。但是在20m以后,各监测点流速下降较快,说明潜水推流器对流速的作用在20m之后显著下降。竖向范围内,同一断面不同水深流速一般2m处的流速最大,其次1m处水深,表层流速一般最小。②潜水推流器在秋冬季节运行时,对湖湾内水质影响各有差异。其中流速和溶解氧浓度呈显著正相关,即流速越大,DO浓度越大;和叶绿素a,高锰酸盐指数呈显著负相关,流速越大,叶绿素a,高锰酸盐指数越低。不同时间段湖湾与对照点TP,TN,氨氮对比结果显示,2014年湖湾TP,TN,氨氮含量整体较对照点(巴渝园)分别下降了20%,20.7%,31.8%,比2012年湖湾监测值分别下降了35%,11.5%,30.7%左右。③湖湾春夏季的水质条件较差,其中Chl-a,CODMn含量较高,SD较小,TN,TP含量较低。夏季温度高,阳光充足,比较适合藻类生长,光合作用强,表层的DO较大,底层水体处于厌氧环境。湖湾秋冬季水质条件较好,其中Chl-a,CODMn含量较低,SD较大,TN,TP含量较高。秋冬季的温度下降,阳光强度弱,藻类生长缓慢,叶绿素a的含量最低。④对湖湾进行综合富营养化指数评价,整个湖湾水质比较稳定,整个监测时期内只有2014.12和2015.01的TSI50,水质良好,其余时间TSI值处于50~60之间,均处于轻度富营养化的状态,轻度污染。2012年和2014年湖湾综合营养状态指数有很大变化,整体来看,2014年湖湾的水质条件好于2012年。自2014.08月推流器运行以来,其运行效果对湖湾水质条件改善明显。潜水推流器的额定功率为5kw,每天运行耗电量较大。潜水推流器长期工作的状况下,可考虑采用太阳能发电系统,通过太阳能发电为潜水推流器提供清洁可再生能源,而且多余的电能可以储存供天气不好或者阳光不充足的时候使用,也可以并网为其他园内其他设施提供能源。不过太阳能发电系统的建设成本较高,确定推广使用之前需做好各项经济指标的比对,为建设太阳能发电系统提供可靠地依据。
[Abstract]:The Dragon King Lake Lake distribution is very irregular shape, palmate, except Lake area is broad, but also the distribution of the size of the bifurcation Bay Bay, most slow water flow, poor mobility, mostly static closed water bodies. The Dragon King Lake the lake bay with Doppler flow monitoring instrument based on the EFDC software the monitoring points of the section flow drawing, by contrast will end point selection in the equipment placed near the side of the dam bridge Lingyun Bay, the initial slow water flow, poor water quality, and is suitable for equipment installation, can better reflect the submerged propellers work. By referring to lots of documents, determine the important basis for diving pushing flow type selection. Research on submerged propellers selection, combined with the terrain conditions and the water quality of Lake Bay status, and finally determine the submerged propellers parameters for impeller diameter 620mm, power 5KW, rated current of 12A, speed 480r/ Min 1300N 184Kg., axial thrust, the research group with the installation of submersible buoy form weight flowmakers. The biomass of phytoplankton depth in the range of 0.5m~3m, flowmakers installed 2.0m depth under water. The research group of 0.10m/s is selected as the push push flow submersible water reaches the limiting value of flow velocity flow. Also, the effective range of current working conditions. Through the definition of submerged propellers operation, explore the operation effect of the water quality conditions of lake bay. The main conclusions are as follows: 1. For different water depths (surface, 2m, 4m) monitoring of each sampling point, the flow rate is 1-2# the largest, reached 0.619m/s, and in the flow rate of 2m at depth velocity than other depth, shows the influence of submerged propellers in the depth of 2m at the maximum, the best effect at.1m depth velocity is relatively large, 1-1#, 2-1# flow rate were 0.488m/s, 0. 489m/s, indicating that the effect of range of submerged propellers in 1~2m water depth is obvious. But after 20m, the monitoring points of flow rate decreased rapidly, that is to push the diving flow velocity decreased significantly after 20m. The vertical range, the same section of different depth and velocity of 2m flow rate at the maximum, followed by 1m. Water depth, surface velocity of the general minimum. The submerged propellers in autumn and winter when running on the lake bay water quality impact is different. The velocity and concentration of dissolved oxygen was positively related to the flow rate, the concentration of DO is higher; and negatively related to chlorophyll a, permanganate index, the higher the velocity, chlorophyll a, permanganate index is low. Different time Bay and the control points of TP, TN, ammonia nitrogen results showed that the 2014 Bay TP, TN, the ammonia nitrogen content compared with the control point (Bayu garden) were decreased by 20%, 20.7%, 31.8%, compared with 2012 Bay monitoring respectively. Decreased by 35%, 11.5%, 30.7%. The bay water quality conditions in spring and summer of the poor, including Chl-a, CODMn content is high, the small SD, TN, TP were low. The summer high temperature, sunshine, more suitable for the growth of algae photosynthesis, strong, the surface of the larger DO, the bottom water in the anaerobic environment of lake. Bay in autumn and winter conditions of water quality better, including Chl-a, CODMn content is low, the larger SD, TN, TP were higher in autumn and winter. The temperature decreased and the sunlight intensity is weak, slow growth of algae, the lowest chlorophyll a content. The comprehensive index of eutrophication of Lake Bay evaluation, the bay water quality is relatively stable, the monitoring period is only 2014.12 and 2015.01 TSI50, the water quality is good, the rest of the time the TSI value is between 50~60, were in mild eutrophic state, light pollution.2012 and 2014 Bay comprehensive nutrition state index has a great change. Overall, the Bay in 2014 Good water quality conditions in 2012. Since the 2014.08 month flowmakers operation, the operation effect on water quality condition of Lake Bay was improved significantly. The rated power of submerged propellers is 5kW, the everyday operation of large power consumption. Submerged propellers long-term working conditions, consider using the solar power system, solar power is through submerged propellers provide clean and renewable energy, and the excess electricity can be stored for bad weather or when the sunlight is not sufficient to use, can also be connected to provide energy for the other in other facilities. But the solar power system construction cost is higher, need to determine the alignment of various economic indicators used before, to provide reliable basis for the construction of solar power generation system.

【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X524

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