超聲波強化蒸發(fā)傳熱性能研究
發(fā)布時間：2018-11-10 17:45
【摘要】：超聲蒸發(fā)器是利用超聲波技術(shù)輔助物料蒸發(fā)濃縮的一種新型蒸發(fā)設備,它特別適用于易結(jié)垢、易發(fā)泡及高沸點物料的濃縮。由于超聲波技術(shù)強化液體蒸發(fā)傳熱的機理性研究不足及沸騰傳熱的復雜性,目前鮮有超聲蒸發(fā)裝置用于工業(yè)生產(chǎn)的報道,且適用于超聲蒸發(fā)器設計計算的基礎數(shù)據(jù)相當匱乏。本文以自來水為實驗物料,研究超聲蒸發(fā)器的傳熱性能,并分析了超聲波強化蒸發(fā)的程度。實驗結(jié)果表明：1)利用單因素法得出各主要操作參數(shù)對超聲蒸發(fā)器性能的影響：傳熱系數(shù),蒸發(fā)效率,蒸發(fā)速率隨著蒸發(fā)溫度,進料流量的增加而增大,隨超聲波功率密度的提高先增大后減小。2)通過分析各主要參數(shù)對超聲波強化傳熱系數(shù)的影響得出：強化效率隨著超聲功率密度的增強,先增大至25.29%而后減�。浑S蒸發(fā)溫度的提高,強化效率由29.85%逐漸減小至24%左右,然后趨于穩(wěn)定；隨傳熱溫差的提高基本穩(wěn)定在20%；隨進料流量的增加由19.4%緩慢增大至22.55%。超聲波作用于蒸發(fā)器時,傳熱系數(shù)提高17.06%～29.85%。3)分別采用正交法和響應面分析法對超聲蒸發(fā)動力學過程進行了回歸分析,得出各主要操作參數(shù)對超聲蒸發(fā)器的總傳熱系數(shù)敏感性：傳熱溫差蒸發(fā)溫度進料流量超聲功率密度。分析對比了所得多元線性回歸模型和多元二次回歸模型：多元二次回歸模型的相關(guān)系數(shù)97.09%和預測精度高達91.89%,可用于估計不同參數(shù)條件下傳熱系數(shù)。并且得出超聲蒸發(fā)裝置的最佳操作條件：蒸發(fā)溫度85℃,處理量481/h,功率密度0.7455W/cm2,傳熱溫差20℃,傳熱系數(shù)理論能達到1185.5W/m2·℃。
[Abstract]:Ultrasonic evaporator is a new type of evaporation equipment which is used to aid material evaporation and concentration by ultrasonic technology. It is especially suitable for the concentration of easily scaling, foaming and high boiling point materials. Due to the lack of research on the mechanism and complexity of boiling heat transfer enhanced by ultrasonic technology, there are few reports of ultrasonic evaporator used in industrial production, and the basic data suitable for design and calculation of ultrasonic evaporator are rather scarce. In this paper, the heat transfer performance of ultrasonic evaporator is studied with tap water as experimental material, and the degree of ultrasonic enhanced evaporation is analyzed. The experimental results show that: 1) the effects of main operating parameters on the performance of ultrasonic evaporator are obtained by single factor method: heat transfer coefficient, evaporation efficiency and evaporation rate increase with the increase of evaporation temperature and feed flow rate. By analyzing the influence of the main parameters on the ultrasonic enhancement heat transfer coefficient, it is concluded that the enhancement efficiency increases to 25.29% at first and then decreases with the increase of ultrasonic power density. With the increase of evaporation temperature, the enhancement efficiency decreases gradually from 29.85% to about 24%, then tends to be stable; with the increase of heat transfer temperature difference, it is basically stable at 20%; with the increase of feed flow rate, it increases slowly from 19.4% to 22.55%. When the ultrasonic wave acts on the evaporator, the heat transfer coefficient is increased by 17.06 and 29.85.3) the dynamic process of ultrasonic evaporation is analyzed by orthogonal method and response surface analysis method, respectively. The sensitivity of the main operating parameters to the total heat transfer coefficient of the ultrasonic evaporator is obtained. The multivariate linear regression model and the multivariate quadratic regression model are analyzed and compared. The correlation coefficient of the multivariate quadratic regression model is 97.09% and the prediction accuracy is as high as 91.89, which can be used to estimate the heat transfer coefficient under different parameters. The optimum operating conditions of ultrasonic evaporator are as follows: evaporation temperature 85 鈩，
本文編號：2323145
[Abstract]:Ultrasonic evaporator is a new type of evaporation equipment which is used to aid material evaporation and concentration by ultrasonic technology. It is especially suitable for the concentration of easily scaling, foaming and high boiling point materials. Due to the lack of research on the mechanism and complexity of boiling heat transfer enhanced by ultrasonic technology, there are few reports of ultrasonic evaporator used in industrial production, and the basic data suitable for design and calculation of ultrasonic evaporator are rather scarce. In this paper, the heat transfer performance of ultrasonic evaporator is studied with tap water as experimental material, and the degree of ultrasonic enhanced evaporation is analyzed. The experimental results show that: 1) the effects of main operating parameters on the performance of ultrasonic evaporator are obtained by single factor method: heat transfer coefficient, evaporation efficiency and evaporation rate increase with the increase of evaporation temperature and feed flow rate. By analyzing the influence of the main parameters on the ultrasonic enhancement heat transfer coefficient, it is concluded that the enhancement efficiency increases to 25.29% at first and then decreases with the increase of ultrasonic power density. With the increase of evaporation temperature, the enhancement efficiency decreases gradually from 29.85% to about 24%, then tends to be stable; with the increase of heat transfer temperature difference, it is basically stable at 20%; with the increase of feed flow rate, it increases slowly from 19.4% to 22.55%. When the ultrasonic wave acts on the evaporator, the heat transfer coefficient is increased by 17.06 and 29.85.3) the dynamic process of ultrasonic evaporation is analyzed by orthogonal method and response surface analysis method, respectively. The sensitivity of the main operating parameters to the total heat transfer coefficient of the ultrasonic evaporator is obtained. The multivariate linear regression model and the multivariate quadratic regression model are analyzed and compared. The correlation coefficient of the multivariate quadratic regression model is 97.09% and the prediction accuracy is as high as 91.89, which can be used to estimate the heat transfer coefficient under different parameters. The optimum operating conditions of ultrasonic evaporator are as follows: evaporation temperature 85 鈩，
本文編號：2323145
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