中国环境科学
中國環境科學
중국배경과학
China Environmental Science
2015年
9期
2690-2697
,共8页
孙昕%刘凌炜%段飞飞%解岳
孫昕%劉凌煒%段飛飛%解嶽
손흔%류릉위%단비비%해악
等温层曝气%溶解氧%模型%曝气量%气泡直径
等溫層曝氣%溶解氧%模型%曝氣量%氣泡直徑
등온층폭기%용해양%모형%폭기량%기포직경
hypolimnetic aeration%dissolved oxygen%model%air flowrate%bubble diameter
分析了等温层曝气器曝气室内气泡-水接触界面的氧传质过程,确定了表征氧传质效果的各项参数,在双膜理论基础上建立了等温层曝气充氧动力学模型及其解析方法.应用本模型预测了美国 Prince 湖等温层曝气器的充氧效果.根据等温层曝气充氧动力学模型的预测结果,随曝气量的增加和气泡直径的减小,氧总传质系数和氧传质速率均增大;随曝气量和气泡直径的增大,曝气效率下降.在等温层曝气器结构固定的情况下,减小气泡直径和增加水深均有利于改善曝气室的充氧效果,尤其是当气泡直径达到 μm 级别时;当曝气量超过一定临界值0.06m3/s时,曝气室的充氧效果略有削弱.根据曝气量对氧传质速率、曝气效率和单位时间内曝气室的充氧量的影响特性曲线,可确定等温层曝气器的优化运行条件.
分析瞭等溫層曝氣器曝氣室內氣泡-水接觸界麵的氧傳質過程,確定瞭錶徵氧傳質效果的各項參數,在雙膜理論基礎上建立瞭等溫層曝氣充氧動力學模型及其解析方法.應用本模型預測瞭美國 Prince 湖等溫層曝氣器的充氧效果.根據等溫層曝氣充氧動力學模型的預測結果,隨曝氣量的增加和氣泡直徑的減小,氧總傳質繫數和氧傳質速率均增大;隨曝氣量和氣泡直徑的增大,曝氣效率下降.在等溫層曝氣器結構固定的情況下,減小氣泡直徑和增加水深均有利于改善曝氣室的充氧效果,尤其是噹氣泡直徑達到 μm 級彆時;噹曝氣量超過一定臨界值0.06m3/s時,曝氣室的充氧效果略有削弱.根據曝氣量對氧傳質速率、曝氣效率和單位時間內曝氣室的充氧量的影響特性麯線,可確定等溫層曝氣器的優化運行條件.
분석료등온층폭기기폭기실내기포-수접촉계면적양전질과정,학정료표정양전질효과적각항삼수,재쌍막이론기출상건립료등온층폭기충양동역학모형급기해석방법.응용본모형예측료미국 Prince 호등온층폭기기적충양효과.근거등온층폭기충양동역학모형적예측결과,수폭기량적증가화기포직경적감소,양총전질계수화양전질속솔균증대;수폭기량화기포직경적증대,폭기효솔하강.재등온층폭기기결구고정적정황하,감소기포직경화증가수심균유리우개선폭기실적충양효과,우기시당기포직경체도 μm 급별시;당폭기량초과일정림계치0.06m3/s시,폭기실적충양효과략유삭약.근거폭기량대양전질속솔、폭기효솔화단위시간내폭기실적충양량적영향특성곡선,가학정등온층폭기기적우화운행조건.
Oxygen transfer process from the air bubbles to the water was mainly analyzed in the aeration chamber of a hypolimnetic aerator, parameters characterizing the effectiveness of oxygen transfer were properly determined,a dynamical model of oxygen transfer for hypolimnetic aeration was developed based on the double-layer theory. The effectiveness of oxygenation was well predicted using the developed dynamical model of oxygen transfer for hypolimnetic aeration. Based on the predicted results using the dynamical model of oxygen transfer, when the air flowrate increased or the bubble diameter decreased, the oxygen transfer coefficient and the oxygen transfer rate increased. When the air flowrate and bubble diameter increased, the aeration efficiency decreased. Under fixed configuration conditions of a hypolimnetic aerator, decreasing the bubble diameter and increasing the water depth above the air diffusors would be helpful to improve the effectiveness of oxygenation in the aeration chamber of a hypolimnetic aerator, especially when the bubble diameter was of micrometer level. When the air flowrate increased to a critical value of0.06m3/s, the effectiveness of oxygenation in the aeration chamber would become weaker. Judged from the influencing characteristic curves of air flowrate on the oxygen transfer rate, aeration efficiency and oxygen input of the aeration chamber per unit time, the optimized operational conditions of a hypolimnetic aerator can be determined.
