Author(s): Haiwen Zhang; Ping Ji; Yijun Zhao; Jue Yuan; Li Zeng; Xiaoli Chen
Keywords: Numerical modelling; Heat dispersion; Cooling water; Water discharge; Inland power plant
Abstract: A numerical modelling study on heat dispersion of cooling water for the purpose of site selection of inland power plants is presented in this study. A 3D hydrodynamic modelling by using MIKE 3 HD with flexible mesh (FM) has been carried out to simulate the distribution of temperature rise due to the cooling water discharge in rectangular channel. A series of scenarios with different ratio of width to water depth (β=B/h) and various ratio of ambient flow discharge to outfall discharge (γ=Q a/Q o) have been simulated. Based on the modelling results, the dispersed areas of temperature rise (1, 2, 3and 4℃) have been counted. Moreover, considering the specific limit on the transverse dispersed distance of temperature rise for environmental protection, the maximum transverse dispersed distance of temperature rise for 1℃ (y) has been analyzed. It was found that, the distance (y) can be approximately described by a function of water depth (h) ,the ratio of width to water depth (β) ,the ratio of ambient flow discharge to outfall discharge (γ) and the ambient Froude number (Fr=U/ (gh) 0. 5, where, U is the ambient current speed) .Thus an approximate estimation of the distance (y) was established. The estimated and observed distance results have been compared, and they matched well. This estimation has been applied to get an approximate limit of the ratio of ambient flow discharge to outfall discharge which can be used as a reference for the site selection of inland power plants.