超声波强化蒸发传热性能研究
发布时间：2018-11-10 17:45
【摘要】：超声蒸发器是利用超声波技术辅助物料蒸发浓缩的一种新型蒸发设备,它特别适用于易结垢、易发泡及高沸点物料的浓缩。由于超声波技术强化液体蒸发传热的机理性研究不足及沸腾传热的复杂性,目前鲜有超声蒸发装置用于工业生产的报道,且适用于超声蒸发器设计计算的基础数据相当匮乏。本文以自来水为实验物料,研究超声蒸发器的传热性能,并分析了超声波强化蒸发的程度。实验结果表明：1)利用单因素法得出各主要操作参数对超声蒸发器性能的影响：传热系数,蒸发效率,蒸发速率随着蒸发温度,进料流量的增加而增大,随超声波功率密度的提高先增大后减小。2)通过分析各主要参数对超声波强化传热系数的影响得出：强化效率随着超声功率密度的增强,先增大至25.29%而后减小；随蒸发温度的提高,强化效率由29.85%逐渐减小至24%左右,然后趋于稳定；随传热温差的提高基本稳定在20%；随进料流量的增加由19.4%缓慢增大至22.55%。超声波作用于蒸发器时,传热系数提高17.06%～29.85%。3)分别采用正交法和响应面分析法对超声蒸发动力学过程进行了回归分析,得出各主要操作参数对超声蒸发器的总传热系数敏感性：传热温差蒸发温度进料流量超声功率密度。分析对比了所得多元线性回归模型和多元二次回归模型：多元二次回归模型的相关系数97.09%和预测精度高达91.89%,可用于估计不同参数条件下传热系数。并且得出超声蒸发装置的最佳操作条件：蒸发温度85℃,处理量481/h,功率密度0.7455W/cm2,传热温差20℃,传热系数理论能达到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，
本文编号：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，
本文编号：2323145
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