湛江湾海域温排水温升分布及热环境容量模拟

Numerical Simulation on the Temperature Rise Distribution and Heat Environmental Capacity Change due to Thermal Discharge in Zhanjiang Bay

【目的】研究湛江湾水域在湾内电厂温排水及潮汐影响下的温升分布情况及热环境容量,为湛江湾的治理、开发与规划提供科学依据。【方法】结合湛江湾内电厂实际排热布局,通过Delft3D建立能反映电厂温排水热力特性的三维数学模型,计算分析特征时刻湛江湾的温升情况,绘制特征时刻的温升分布图,并利用试算法计算湛江湾近海海域热环境容量与剩余热环境容量。【结果与结论】湾内三处电厂排热口附近均有一定的热量积累,3.5℃的温升包络面积在大潮涨、落憩时分别为0.96 km^(2)、1.4 km^(2);在小潮涨、落憩时分别为4.1 km^(2)、3.6 km^(2)。潮动力对半封闭海湾湛江湾温升过程起主导作用。大潮时高温升面积小,低温升面积大,小潮时反之。在现有的排放布局下,五里山港海洋保护区在大潮涨潮时,出现温升超过限制标准情况。热环境容量:京信电厂>湛江电厂>湛江钢铁电厂,京信电厂附近海域剩余热环境容量最大(66.4%),可适当加以开发利用;湛江电厂附近海域热环境容量已经超标77.6%,需削减排放量或改进工艺。

【Objective】 This paper comprehensively analyzes the problem of thermal discharge of multiple power plants in Zhanjiang Bay, so as to provide scientific reference for the treatment,development and planning of Zhanjiang Bay. 【Method】Combined with the actual thermal discharge of the power plant in Zhanjiang Bay, a three-dimensional mathematical model is established through Delft3D, reflecting the thermal characteristics of the thermal discharge of the power plants and predicting the temperature rise in Zhanjiang Bay at the characteristic time, plotting the temperature rise distribution at the characteristic moments, and test algorithm is used to calculate the thermal environment capacity and residual thermal environment capacity of Zhanjiang Bay.【Result and Conclusion】There is a certain amount of heat accumulation near the heat outlet of the three power plants, the envelope areas of temperature rise of 3.5 ℃ are 0.96 km^(2) and 1.4 km^(2) respectively at spring tide’s flood slack and ebb slack. Tidal power plays a leading role in the temperature rise process of Zhanjiang Bay,which is a semi closed Bay. In spring tide, the area of high temperature rise(3.5 ℃) is small, the area of low temperature rise(0.5 ℃) is large, while the areas during neap tide are opposite. In the existing distribution of thermal discharge, the temperature rise in Wulishan marine reserve exceeds the limit standard when the spring tide rises. Thermal environmental capacity: Jingxin power plant > Zhanjiang power plant > Zhanjiang iron and steel power plant. The residual thermal environmental capacity of the sea area near Jingxin power plant is the largest(66.4%), which can be properly developed and utilized;The thermal environment capacity of the sea area near Zhanjiang Power Plant is 77.6% over the limit standard, and it is necessary to reduce the thermal discharge or improve the process.