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水温分层是深水型水库水质内源污染的主要诱因。针对现有消减水温分层技术的高能耗问题,尝试利用扬水曝气器的周期性出流作为扰动源,在气水两相流条件下诱导产生内波。基于模型水库水温垂向密度剖面的历时信息,计算水库内波的特征参数,分析内波的特性及其消减水温分层的效果。当曝气量为50~200 L/h、跃温层温度梯度为0.34~0.49℃/cm时,在特定条件下能产生内波,内波的波幅在跃温层浮力频率最小处最大。随曝气时间推移,内波的能量逐渐耗散,波幅逐渐减小,内波有破碎趋势。随曝气量减小,内波的特征参数值的总趋势是先逐渐增大到极值,再逐渐减小。随温度梯度增大,内波周期有减小趋势,波速、波长、波幅则相反。内波特性受温度梯度影响较大。在本中试条件下,相对传统的循环水流混合,内波混合可使消减分层的效率提高25%~60%。
Water temperature stratification is the main cause of endogenous pollution of water quality in deepwater reservoirs. Aiming at the problem of high energy consumption of existing water temperature stratification dewatering technology, attempts are made to utilize the periodic outflow of the pumped aerator as a disturbance source to induce the generation of an internal wave under the condition of gas-water two-phase flow. Based on the time-history information of the vertical density profile of the model reservoir water temperature, the characteristic parameters of the wave in the reservoir are calculated, and the characteristics of the internal wave and the effect of water temperature stratification are analyzed. When the aeration rate is 50 ~ 200 L / h and the gradient temperature gradient is 0.34 ~ 0.49 ℃ / cm, the internal wave can be generated under certain conditions. The amplitude of the internal wave is the largest at the minimum of the buoyancy frequency of the thermal layer. With the aeration time, the energy of the internal wave gradually dissipated, the amplitude decreased gradually, the internal wave has a tendency to break. With the decrease of aeration, the general trend of the characteristic parameters of internal waves is to gradually increase to the extreme value and then decrease gradually. With the increase of temperature gradient, the internal wave period tends to decrease, and the wave speed, wavelength and amplitude are opposite. Internal temperature characteristics of the greater impact of temperature gradient. Under the conditions of this pilot, the mixing efficiency of inner-wave mixing can be reduced by 25% -60% compared with that of traditional circulating water.