有限时间排放的污染扩散模式及污染特征

ON DIFFUSION MODEL FOR POLLUTION RELEASE IN FINITE DURATION OF TIME AND ANALYSIS OF THE CHARACTERISTICS

关键词:  有限时间  扩散模式  烟羽模式  烟团模式

Key words:  Finite duration of time  Diffusion model  Plume model  Puff model

摘要:

利用烟团模式的思想,建立起有限时间排放的污染扩散模式。验证了在排放时间极短时,该模式和瞬时点源扩散的解析解完全一致;在排放时间充分长时,和连续点源的烟羽扩散模式有非常好的一致性。有限时间排放污染的特征,是随着事故发生、排放开始,地面污染浓度有一个很快的积累过程,从近源处开始浓度达到一种动态平衡;事故结束(即没有排放)时,由于大气的“净化”能力,污染慢慢减轻,直到最后“消失”.

Abstract:

Following the conceptual idea of puff model,a diffusion model that describes pollutants discharged in finite duration of time is set up,with which a complete consistence between the model and the analytic solutions with extremely short duration of release from a transient point source,and a perfect conformity between it and the plume model with sufficiently long duration of release in the form of a continuous point source,are obtained.The discharge of pollution within a limited time is featured by attainment of dynamic equilibrium of concentration at the ground surface beginning from the vicinity of the source shortly after the occurrence of accidents and subcequent release of pollution,and by eventual “disappearence” of pollution that is gradually reduced due to the purifying effect of the atmosphere when the accidents are over,or,there occurs an end to the release.