Diffusion Characteristics and Mechanisms of Thermal Plumes from Coastal Power Plants: A Numerical Simulation Study

Abstract

Plumes include thermal plumes and cold plumes, of which thermal plumes receive more attention. Thermal plumes refer to the formation of high-temperature fluid structures near a heat source, which diffuse and propagate within the surrounding environment. In this study, we simulate the formation and evolution of thermal plumes using numerical modeling. Taking Wushashan Power Plant in Xiangshan Bay as an example, the diffusion characteristics of the thermal plume near the power plant were simulated by the optimized FVCOM. Combined with statistical methods and advanced mathematical models, the plume diffusion range under different working conditions was quantified, and the diffusion mechanism was studied. For example, we found that when the flow velocity is halved, the diffusion area of the surface thermal plume decreases by more than half. When the flow rate in Xiangshan Bay is reduced to 5 m3/s, the area of surface temperature rise plumes is small. Using the Richardson number, the characteristics and mechanisms of stratification/mixing near the power plant were explored. It was found that the flow field near the power plant was mainly affected by the momentum of the outlet. During a typhoon, the wind strength and path impact thermal plume diffusion via wind-driven flow.