热通量计算方法在开敞海域温排水模拟中的应用——以田湾核电站为例

海气热通量对海气的热量交换具有重要的影响,能够很大程度地影响局部海域的热量扩散情况。在滨海电厂所在海域,由于温排水与环境水域温差引起的斜压效应,将对附近海域温度分布、局部环流结构变化等海洋生态环境造成影响,因此现有的数学模型要考虑海气热通量才能更加准确地模拟温排水造成的温升场。本文在了解田湾核电站温排水特点和附近海域潮流特征的基础上,应用FVCOM数值模式,采用《物理海洋学》中的海表面热通量计算方法,建立了田湾核电站附近海域温排水数值模型,对温排水造成的温升进行了模拟。模式考虑斜压效应,在排水口考虑了温排水的叠加效应,通过与实测资料比对表明:该文建立的田湾核电站温排水模型可以较好地模拟该海域的温度变化和温排水造成的温升变化。     

潮州电厂温排水特征分析

本文采用数值模拟和实测资料的方法对潮州电厂温排水扩散特征进行分析,并采用实测资料对模拟结果进行验证,结果显示;模拟结果与实测结果扩散面积和扩散方向基本一致;由于地形的原因,电厂温排水的排水口附近海域水动力较弱,与外围水交换能力较差,导致温排水涡积现象很明显;夏季大(小)潮温排水扩散面积小于冬季大(小)潮温排水扩散面积,大潮时温排水扩散面积小于小潮;取水口温升小,温排水排放对电厂取水没有明显影响.     

海水淡化浓海水与电厂温排水混排方案研究

本文以渤海湾为例，运用MIKE3 FM数值模拟软件建立了渤海湾天津附近海域海水淡化浓海水与电厂温排水混合排放温盐扩散三维数值模型，开展了浓海水和温排水不同混合比例温盐扩散对比研究。研究结果表明：浓海水与温排水混合排放可以使受纳海域盐升范围显著减小，并且混合比例越高，效果越明显。在温升影响方面，与等量温排水单独排放相比，混合排放会使底层海域温升包络面积增大，表层减小，但当混合比例超过1：30（温排水量约为35 m³/s），表层和底层海域温升包络面积接近于等量温排水单独排放的温升包络面积；综合考虑温盐扩散，当海水淡化浓海水排放量在10×104 m³/d，盐升不超过20时，与温排水混合排放比例超过1：30（温排水量超过35 m³/s），盐度在排放口附近可稀释到背景值，由于混合排放密度变化引起的温度下沉影响几乎可以忽略不计。相关研究结论可为海水淡化浓海水科学排放/推动海水淡化和海洋环境和谐可持续发展提供技术支撑。     

华能日照电厂二期扩建工程温排水排水方案优选

在已建立潮流模型的基础上,研究温排水的输移扩散,以华能日照电厂为例,对各温排水设计方案(包括排水口位置、排水量和温升等)进行预测分析.最佳推荐方案是一、二期工程温排水由排水口B合排.本文结果可为该海域海洋环境保护与管理提供科学依据.     

象山港电厂温排水的实测和数值模拟研究

为了研究象山港电厂温排水的热污染问题,对其附近海域的潮流和水温扩散进行了实测研究,给出了该海域潮流及水温扩散的特征。同时利用近海潮流模式(ECOMSED)建立了象山港潮流三维数值模型,对研究海域的潮流和水温扩散进行了模拟,得到了大小潮涨、落憩时刻的温升场的扩散范围,对比分析发现数模结果与实测结果符合较好。     

黄骅电厂二期工程温排水排放方案优选

在利用分步杂交有限元方法建立渤海湾潮流场的基础上,通过数值模拟的方法建立黄骅电厂温排水海域的温度场,对不同温排水设计方案进行了预测分析。设计方案充分考虑了排放口位置、排水量和温升对海域环境造成的影响,设计了一、二期工程排放口分建和合建时的五种方案。预测结果的对比分析显示,方案V(一、二期工程温排水集中由2排放)是最佳方案。     

Landsat-8热红外数据监测田湾核电站温排水分布

基于2015—2017年的多景Landsat-8热红外数据,采用辐射传输方程法反演田湾核电站邻近海域海面温度,依据反演所得海面温升分布图对温排水的分布特征进行分析。结果表明:田湾核电站温排水的扩散方向和影响范围与潮汐状态密切相关。在涨潮中期阶段,温排水分布范围较小,其中1℃以上温升区域面积不足10 km~2;在高、低平潮阶段,温排水扩散面积相近,其中1℃以上温升区域面积约15 km~2;在落潮中期阶段温排水分布范围最大,1℃以上温升区域面积可达30 km~2,但4℃以上高温升区域面积较小。高温升区域多出现在排水口以南至以东附近海域,随着温排水向周围海域扩散,温升逐渐呈衰减分布。     

大亚湾海域温排水三维数值模拟

为了研究大亚湾海域核电站温排水热污染问题,本文利用POM模式建立了大亚湾潮流三维数值模型,在模型验证良好的基础上,结合建立在对流扩散理论基础之上的输运扩散模型,对大亚湾核电站和岭澳核电站一期工程合排后夏季两核电站温排水的稀释扩散过程进行了数值计算,得到了涨憩、涨急、落憩、落急四个典型时刻温升场的特征值,并进一步分析了温升场的变化特征。     

浙江苍南电厂冷却水温排放的数值模拟

电厂排放的冷却水水量大且热量高,其排放的热水将引起周围水域水温的升高,导致不同程度的热污染.针对浙江苍南电厂附近海域水流和污染物的对流扩散特点,采用MIKE21软件对电厂温排水进行数值模拟,分析不同潮型、不同流量及不同季节下的最大温升包络面积和取水口的温升变化.研究结果表明,电厂冷却水温排放的最大温升包络面积范围与流速和水深的关系密切.从本工程的情况来看,在高温升(4 ℃)区以保证率为97%的低水位潮型下的最大温升包络面积为最大,达0.69 km2,大潮、中潮和小潮相应的面积分别为0.63、0.66和0.48 km2;在低温升(0.5 ℃)区以小潮相应的面积为最大,达14.96 km2,中潮、大潮和保证率为97%的低水位潮型相应的面积分别为13.48、10.30和6.90 km2.温升包络面积与电厂冷却水的排放量不为线性关系.冬季电厂冷却水排放的温升包络面积大于夏季,冬季4 ℃温升包络面积是夏季的3倍,其它各级温升包络面积为夏季的1.1～1.4倍.由于取排水口被挡沙防浪堤隔开,故取水口区域的温升较小.研究成果可为电厂的建设提供依据.     

青岛滨海电厂温排水对海洋生态环境影响研究现状

随着滨海电厂的迅速发展,电厂温排水排放对邻近海域的生态环境影响越来越受到人们的关注。文章概括了青岛电厂温排水数值模拟现状、温排水排放对海洋生态环境影响方面的一些研究成果,并提出了存在的问题和今后应关注的研究方向。     

Landsat-8 TIRS数据在某核电站温排水监测中应用探讨

为探索Landsat-8 TIRS热红外数据在核电站温排水监测的应用能力,以某核电附近海域为研究区域,采用单窗算法建立核电站附近海域表面温度反演方法,并将该结果与时相接近的MODIS海温产品数据进行了对比分析。结果表明,反演的温度场可较精细地刻画该核电站附近温度场的分布情况,Landsat-8 TIRS数据可实现较高精度的核电站温排水监测。     

红沿河核电站邻近海域海流特征观测与分析

掌握核电站周边海域流场特征对保障核电冷源安全及研究排水口温排水输运规律具有重要意义。基于2013年12月~2014年2月在红沿河核电站邻近海域获取的四个站点海流连续观测资料,利用低通滤波和调和分析的方法,分析了该海域的余流和潮流特征。结果表明,核电站邻近海域冬季余流流速大于秋季,且随深度增加而减小;中层附近余流变化较小,越接近底层余流变化越大;海域潮流类型属于规则半日潮流,且浅水分潮特征显著; M_2和K_1分潮流的最大流速随深度增加而减小;除取水口站位外,其他站位主要分潮流运动形式皆表现为往复流特征。     

Application of satellite infrared data for mapping of thermal plume contamination in coastal ecosystem of Korea

The 5900 MW Younggwang nuclear power station on the west coast of Korea discharges warm water affecting coastal ecology [KORDI report (2003). Wide area observation of the impact of the operation of Younggwang nuclear power plant 5 and 6, No. BSPI 319-00-1426-3, KORDI, Seoul, Korea]. Here the spatial and temporal characteristics of the thermal plume signature of warm water are reported from a time series (1985-2003) of space-borne, thermal infrared data from Landsat and National Oceanic and Atmospheric Administration (NOAA) satellites. Sea surface temperature (SST) were characterized using advanced very high resolution radiometer data from the NOAA satellites. These data demonstrated the general pattern and extension of the thermal plume signature in the Younggwang coastal areas. In contrast, the analysis of SST from thematic mapper data using the Landsat-5 and 7 satellites provided enhanced information about the plume shape, dimension and direction of dispersion in these waters. The thermal plume signature was detected from 70 to 100 km to the south of the discharge during the summer monsoon and 50 to 70 km to the northwest during the winter monsoon. The mean detected plume temperature was 28 degrees C in summer and 12 degrees C in winter. The DeltaT varied from 2 to 4 degrees C in winter and 2 degrees C in summer. These values are lower than the re-circulating water temperature (6-9 degrees C). In addition the temperature difference between tidal flats and offshore (SSTtidal flats - SSToffsore) was found to vary from 5.4 to 8.5 degrees C during the flood tides and 3.5 degrees C during the ebb tide. The data also suggest that water heated by direct solar radiation on the tidal flats during the flood tides might have been transported offshore during the ebb tide. Based on these results we suggest that there is an urgent need to protect the health of Younggwang coastal marine ecosystem from the severe thermal impact by the large quantity of warm water discharged from the Younggwang nuclear power plant.     

核电站附近海域漂流海藻的漂移路径数值模拟

研究核电站附近海域漂流海藻的漂流路径对保障核电站冷源安全具有重要意义。本研究根据辽东湾东部海域漂流海藻的分布特征,构建该海域的二维水动力和粒子追踪数值预测、预报模型,基于近年实际观测的海流和潮位数据,对水动力模型进行验证,并根据2019年5月至8月释放北斗和GPS浮标采集数据,对该海域相同工况下的海藻漂移路径进行校验,均吻合良好。同时,对该海域7月大潮期,取水口附近海域的海藻堵塞风险进行了模拟分析,得到各不同工况下,漂流海藻到达取水口定义威胁区范围内的时间。结果表明,该数值模型能够对漂流海藻的漂移路径进行准确模拟,可为科学规避或有效减轻漂流海藻对核电站冷源取水口的堵塞风险提供技术支撑。     

滨海核电站取水口精细流场测量的设计与实例

冷源取水安全是核电运行安全的重要部分,会受到多种海洋堵塞物的威胁。为科学支撑滨海核电站取水口堵塞物防治工作,亟须掌握取水口的精细流场。走航和定点相结合的测量方式可同时获取流场的时空变化特征,适用于滨海核电站取水口精细流场的测量;走航测量宜采用具有底跟踪功能的ADCP,该设备具有测量精度高和数据处理简便的优点,然而在使用中应注重规范性以减少测量误差;以潮流为主的海域在涨急和落急时段的流场较稳定,在这段时间内进行走航数据插值可得到涨急和落急时段的精细流场;应用该方案获取某滨海核电站取水口的精细流场,测量结果显示取水口的流场较复杂,小范围流场受取水影响显著,呈现非潮流特征。     

Dynamics of the Mackenzie River plume on the inner Beaufort shelf during an open water period in summer

The oceanographic conditions of the Mackenzie River plume in the Arctic Ocean were examined during a 12-day period in August 2007. Field observations in the river channel and the delta region (2–6 m depth), ship-based observations on the shelf and satellite observations of sea surface temperatures indicate that movements of plume density fronts cause changes in water temperatures of over 10  C over a few days. We used a 1D model to compare the strength of stratification versus surface wind stress, and a 3D numerical model to simulate the plume motions under forcing from the river flows, local wind and water level variations from tides and wind-driven surge. The results indicate that the coastal region is stratified with a ∼2 m thick surface plume even in water depths of 3–4 m, resulting in strong vertical variation of horizontal currents. Moderate easterly winds of 5–10 m/s are sufficient to induce offshore transport of the surface plume and onshore transport of the deeper shelf water, leading to large fluctuations in temperature and salinity in the coastal region. This study examined a period of offshore transport and mean water level set-down, and indicates the rapid response of the plume to wind over the shallow delta.     

Nutrient transport from an artificial upwelling of deep sea water

The transport of nutrient-rich, deep sea water from an artificial upwelling pipe has been simulated. A numerical model has been built within a commercial Computational Fluid Dynamics (CFD) package. The model considers the flow of the deep sea water after it is ejected from the pipe outlet in a negatively buoyant plume (densimetric Froude number = −2.6), within a stably stratified ocean environment subject to strong ocean current cross flow. Two cross-flow profiles were tested with momentum flux ratios equal to 0.92 and 3.7. The standard k-ε turbulence model has been employed and a range of turbulent Schmidt and Prandtl numbers tested. In all cases the results show that the rapid diffusion of heat and salinity at the pipe outlet causes the plume to attain neutral buoyancy very rapidly, preventing strong fountain-like behavior. At the higher momentum flux ratio fountain-like behavior is more pronounced close to the pipe outlet. The strong cross-current makes horizontal advection the dominant transport process downstream. The nutrient plume trajectory remains largely within one relatively thin stratified layer, making any ocean cross-flow profile less important. Very little unsteady behavior was observed. The results show that the nutrient is reduced to less than 2% of its inlet concentration 10 meters downstream of the inlet and this result is largely independent of turbulent Prandtl or Schmidt number. Initial results would suggest that if such an artificial upwelling were to be viable for an ocean farming project, a large number of upwelling pipes would be necessary. Further work will have to determine the minimum nutrient concentration required to sustain a viable phytoplankton population and the required spacing between upwelling pipes.     

Peculiarities of Polluted Water Spreading from a Submarine Source in Stratified Coastal Environment

We study the spreading of wastewaters from an underwater source in a stratified coastal environment using the results of satellite monitoring and mathematical modeling. The problem is considered as applied to deepwater discharge in the region of Golubaya Bay of the Black Sea near Sebastopol. The main factors preventing upwelling of pollution to the sea surface are analyzed on the basis of a numerical model. It is shown that peculiarities of wastewater spreading depend on the character of stratification and velocity of the background current. The main factor influencing the uplift of these waters to the surface is the existence of water layers with high vertical gradients of water density. We reveal the structure of the wastewater field consisting of a plume and a jet extended in the direction of the background current, which is located in the density interface. If stratification is weak, the plume may reach the sea surface and form a local region of water pollution, which is recorded in multispectral satellite images. It is found that the mass of polluted waters is characterized by negative anomalies of temperature and salinity.     

湛江近海M2分潮的数值模拟

利用潮汐模型,在高分辨率的自适应曲线网格下,采用潮汐调和常数作为控制模拟精度的方法,模拟了洪江附近海域M2分潮的运动特征。模拟所得的潮汐调和常数同实测值相比,误差较小。根据模拟结果绘制的M2分潮的同潮图,揭示了湛江附近海域M2分潮振幅和迟角的分布特征以及M2分潮的传播和发展规律。模拟得到的M2分潮分别在涨憩、落憩、涨急和落急几个典型时刻的流场,揭示了湛江附近海域M2分潮潮流的分布特征及其运动规律。