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

Study on computing methods of heat fluxes in simulating the diffusion of cooling water in the open area——Acase study in the Tianwan nuclear power station

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。

The variation of air-sea heat flux has important influence on heat exchange between ocean and atmosphere, and greatly affects the heat diffusion of cooling in local area. Near coastal power stations the buoyancy effect yielded by the difference of temperature between the cooling water and the background water will affect the distribution of temperature nearby, variation of local circulation and other ocean ecosystem. Therefore, the mathematical models must consider air-sea heat flux in order to simulate the temperature rise caused by thermal discharge accurately. On the basis of the features of thermal discharge and the tidal flow characteristics in Tianwan nuclear power station, a three-dimensional ocean model FVCOM is used. Besides, a surface heat flux calculating method is introduced into the model and then a thermal discharged including temperature and temperature rise is established in this paper. The barotropic pressure gradient force is considered in this model. Discharging temperature is set to water intake temperature plus 8℃ rise from the plant, which includes the impact from the temperature rise of water intake. Validations results show that the model in this paper can well simulate the temperature rise caused by thermal discharging.