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在大型火、核电厂中,大水域火、核电厂温排水影响受纳水体的温升变化需要进行物理模型试验研究。基于温度测控仪技术,以某核电厂温排水不同温升变化影响为基础,对取、排水口附近水体表面温升、横断面温升及轴线方向的温升进行观测。研究设计出多路温度测控系统,实现对温排水物理模型取、排水口多点温度观测布置,从而给模型试验研究带来有依据的观测数据。 相似文献
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非结构化网格在印尼亚齐电厂温排水模型中的应用研究 总被引:2,自引:2,他引:0
印尼亚齐(ACEH)电厂取水口温升是判断工程平面布置方案优劣的关键。应用局部加密的非结构化网格建立了平面二维潮流温排水数学模型。该模型能很好地描述复杂地形,既保证了工程区域水动力计算精度,也减少了计算量。在水动力计算过程中考虑了洋流和季风等长周期动力因素,研究了温排水在这种长周期动力条件下的扩散规律。计算了不同布置方案条件下温排水的影响范围,对不同布置方案进行了评价。 相似文献
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《水道港口》2017,(1):26-30
大量温排水不断地排入海域将引起水温升高,导致不同程度的热污染。本文基于平面二维理想水池数值模拟实验,揭示了沿海电厂温排水热扩散对周围水动力条件的响应机制,分析了温排水在不同水深和流速条件下的最大温升包络面积变化情况。研究结果表明,流速越大温升降低快,高温升(4℃)包络面积越小。在水深为4m时,低温升(1℃)包络面积并没有随流速的增大而减小,而是呈增大的趋势。当水深为6 m、8 m、10 m时,低温升(1℃)包络面积随流速的增大而减小。同一潮差条件下,随着水深的增大,1℃、2℃、3℃、4℃温升包络面积均减小,而且温升等值线的温升值越大,其包络面积平均减小的比例越大。最大温升包络线面积与潮流流速和水深关系密切。 相似文献
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文章以印尼某燃煤电厂工程为背景,研究了取排水明渠的不同布置形式对温排水扩散趋势和取水口温升的影响。并对原设计方案进行优化,在取水温升满足设计要求的条件下使工程更为经济合理。可为类似工程提供参考。 相似文献
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This paper describes the development and application of a 3-dimensional model of the barotropic and baroclinic circulation on the continental shelf west of Vancouver Island, Canada. A previous study with a 2D barotropic model and field data revealed that several tidal constituents have a significant baroclinic component (the K1 in particular). Thus we embarked on another study with a 3D model to study the baroclinic effects on the residual and several selected tidal constituents.The 3D model uses a harmonic expansion in time and a finite element discretization in space. All nonlinear terms are retained, including quadratic bottom stress, advection and wave transport (continuity nonlinearity). The equations are solved as a global and a local problem, where the global problem is the solution of the wave equation formulation of the shallow water equations, and the local problem is the solution of the momentum equation for the vertical velocity profile. These equations are coupled to the advection-diffusion equation for density so that density gradient forcing is included in the momentum equations. However, the study presented here describes diagnostic calculations for the baroclinic residual circulation only.The model is sufficiently efficient that it encourages sensitivity testing with a large number of model runs. In this sense, the model is akin to an extension of analytical solutions to the domain of irregular geometry and bottom topography where this parameter space can be explored in some detail.In particular, the consequences of the sigma coordinate system used by the model are explored. Test cases using an idealized representation of the continental shelf, shelf break and shelf slope, lead to an estimation of the velocity errors caused by interpolation errors inherent in the sigma coordinate system. On the basis of these estimates, the computational grid used in the 2D model is found to have inadequate resolution. Thus a new grid is generated with increased accuracy in the region of the shelf break. However, even with increased resolution, spurious baroclinic circulation seaward of the shelf break and in the vicinity of Juan de Fuca canyon remained a significant problem when the pressure gradient terms were evaluated using the σ coordinate system and using a realistic density profile.With the new grid, diagnostic calculations of the barotropic and baroclinic residual circulation are performed using forcing from the observed σt (density) field and from the gradient of this field. 相似文献
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龙口港扩建工程航道规划潮流分析 总被引:3,自引:1,他引:2
文中建立了龙口湾正交坐标系下变网格二维潮流数学模型,利用数值模拟成果分析了龙口湾潮流分布与变化规律。根据潮流分布特点,提出利用屺坶岛对波浪的掩护作用在岛头西部深槽布置新航道走向时,潮流方向与航道交角以及航道横向流速小,有利于航道稳定和船舶航行安全。研究了港口平面规划方案与航道扩建方案共同作用下的港区和航道的潮流变化特征,研究表明:在屺坶岛掩护区内侧沿等深线向布置码头前缘线和航道,通过适当规划可使码头泊位区和航道区水流平顺,潮流流向基本平行于航道走向和码头前沿线。 相似文献
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茅尾海浅滩位于河流出口与潮水相互作用的区域,航道开发面临特殊的水流、泥沙问题。借助潮流物理模型试验,模拟整个茅尾海海域潮流情况,对开发航道方案流态、潮流场变化进行模型试验对比分析,对航道泥沙淤积问题进行计算分析。试验及分析结果表明:3个方案中,瓦泾江出口航道挖深最大,航道水流增加最大,淤积强度也最大,不利于航道维护;大榄江航道方案B利用深槽,挖深较小,水流变化也不大,但航道最大横流最大,不利于船舶航行安全。鉴于在河流出口与潮水作用浅滩开挖航道将面临落潮归槽水流影响、局部流速及淤积量增加较大、航道拐弯处横流太大影响船舶安全等问题,航道开发应尽量利用横流较小的深槽,可适当进行开挖。 相似文献
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徒骇河坝上闸下游通航研究 总被引:2,自引:1,他引:1
建立了徒骇河二维潮流数学模型,模型采用数学物理方法,将不规则域下求解变换成矩形规则域下求解,计算中,首先采用天然实测资料对模型进行率定,通过有关参数调整,使数值计算成果与天然实测资料达到精度要求。然后通过对自然状态下潮流过程的模拟,分析河段通航条件以及潮位、潮流特征。随后对航道不同疏浚方案和取水条件与潮流的相互影响进行计算,研究航道不同疏浚方案引起的潮流变化。最后采用分析方法,对航道不同扩建方案的回淤以及取水口最大取水能力进行预测。 相似文献
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It is often advantageous to model a semi-enclosed estuarine or coastal embayment (e.g. fish farms or tidal inlets, or typhoon shelters) as a separate system within a larger water body connected to the outer sea. The water quality of the system depends crucially on its flushing time—the average time of a particle in the system. The flushing time is governed by the barotropic and baroclinic tidal exchanges between the system and the outer sea. We describe herein a general method to determine systematically the flushing time of a stratified water body via a numerical tracer experiment. Numerical solution of the 3D flow and mass transport equations for many practical problems show that the tracer mass removal process depends on the physical topography and bathymetry, tidal range and the degree of stratification in the outer sea. Field application suggests that the tracer mass variation can be well approximated by a double-exponential decay curve that can be described by three flushing coefficients. Using a simple analytical two-segment model, the flushing coefficients can be given a clear physical interpretation, and the flushing time can be easily determined in terms of the coefficients. The method is illustrated by application to a number of tidal inlets in Hong Kong, in both the dry and wet season. The connection between the numerically determined flushing time and the traditional bulk flushing time obtained from salt-balance methods is established. 相似文献
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滨州港大堡泊位扩建工程潮流分析 总被引:4,自引:1,他引:3
建立了套尔河15 km河段二维潮流数学模型。计算中首先采用天然实测资料对模型进行率定与验证,通过有关参数调整,使模型数值计算成果与天然实测资料达到精度要求。然后通过对河段自然条件下实测潮位、潮流过程进行的模拟,分析了工程区潮流变化特点。随后对泊位扩建工程措施的不同工况条件与潮流的相互影响进行了模拟,分析了各方案的潮流情况,对不同规划方案成果的优劣进行了比较。方案三在新老码头区潮流流向平顺、流速增加、无回流,利于港池稳定;河道宽阔利于船舶进出码头;岸上施工便利,是扩建工程泊位规划的优选方案。为规划设计提供了科学依据。 相似文献
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J.M. de Kok 《Journal of Marine Systems》1996,8(3-4)
The outflow of Rhine water into the shallow Southern Bight of the North Sea leads to almost discontinuous vertical density distributions and sharp frontal structures around the river mouth. Strong tidal motion, wind and baroclinic effects have large influence on the dynamics and dispersion of river water. A three-dimensional tidal model, including advective and diffusive transport of salinity, is used in the two-layer mode for simulation of Rhine water outflow to quantify the interaction of the different processes and the effect on dispersion and mixing of river water. Layer depths are adjusted in a way that no advective transports between upper and lower layer take place in case of sufficiently stable stratification. In case of weak or no stratification the upper layer depth is fixed, and advective transports between layers are computed. Model results show frontal eddy development and (limited) growing internal waves due to baroclinic instability. Comparisons with observational data are presented. 相似文献
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