【作者】 陈磊；

【导师】 费学宁；

【作者基本信息】 天津大学 ， 环境工程， 2015， 博士

【摘要】 在全球经济快速发展同时,无论是工业领域还是水资源淡化领域,低能耗处理高浓度含盐废水及资源化,仍是广大科研工作者关注的热点问题。介观喷雾蒸发分离浓盐水脱盐技术不仅具有节能低碳的优点,对高浓度含盐废水资源化利用还具有积极意义,同时该工艺与膜法结合可有效地提高浓盐水的处理效率。构建介观喷雾蒸发分离高浓度盐水处理系统,完成系统脱盐机理、运行测试、性能模拟和初步的经济性分析研究,主要结论如下:1、构建介观喷雾蒸发分离浓盐水系统,系统由供热系统、雾化系统、水路系统、气路系统和回收系统等组成。建立高浓度盐水介观喷雾蒸发过程的离散相模型并进行验证,运用Fluent软件对高浓度盐水介观喷雾蒸发分离过程进行了模拟仿真,着重探讨了不同压缩空气气压、热空气温度、流量、浓盐水进料水流量对浓盐水的蒸发量和蒸发率的影响,实测对比分析发现,实际测试与模拟结果的变化趋势一致,说明模型合理。2、通过试验研究浓盐水介观喷雾蒸发效率,得出系统最优工况为:空气压缩机气压值为0.3 MPa,热空气流量为65 m3/h,热空气温度为270℃,进料流量为11 L/h;建立两相流喷嘴介观喷雾性能测试系统,通过试验分析两相流喷嘴雾化效果发现:最佳液压为0.1 MPa,最佳气压为0.2 MPa;液体温度越高,雾化液滴的平均粒径越小;含盐量对雾化效果影响较小。3、设计构建槽式中高温太阳能集热器,研究槽式太阳能集热器的集热性能,拟合空气流量与热利用效率关系的二次抛物线,并对拟合的空气流量与热利用效率的关系式进行误差分析,该拟合的关系式可行。4、构建槽式太阳能介观喷雾蒸发浓盐水系统,在最优工况条件下进行了高浓度盐水浓度测试,可以将浓度为146.79 g/L的浓盐水浓缩成351.88 g/L的浓缩液同时有干盐粒结晶析出;在日照充足的天气条件下,太阳能介观喷雾蒸发系统喷蒸浓盐水8小时比电能集热系统节省近70%的电耗。通过Colebrook White阻力理论分析,若对系统进行优化,其耗电量将进一步降低。更多还原

【Abstract】 With the blossom of global economy, brine disposal with low energy consumption and reutilization is still a hot issue both in industry and desalination field. Brine mesoscopic spray evaporation technology not only has advantages of energy saving and low carbon dioxide release, but is useful to reutilization of high concentration brine. In addition, the technology integrated with membrane process can enhance the brine disposal efficiency.In this paper, a mesoscopic spraying evaporation system is applied to high concentration brine disposal. A running test is conducted and the desalting mechanism, performance simulation as well as economic analysis of this system have been investigated. The main conclusions are as follows:1.The mesoscopic spraying evaporation system consists of five components, including heat supply system, evaporation system, feed supply system, gas system, and recovery system. A discrete phase model in brine mesoscopic spraying evaporation system was developed.The brine droplet evaporation and diffusion process in heating airflow was simulated by Fluent. This model was verified by comparing simulation temperature with the experimental. Several operating parameters, including compressed air pressure, temperature and flux of heating air, feed rate of brine, were investigated to examine their effects on the evaporation(E) and the evaporation rate(R). It must be stressed out that the simulation results showed a great agreement with the measured ones.Therefore, the model is reasonable.2. Experiments were conducted to enhance spray evaporation efficiency. It was found that the optimum working condition iscompressed air pressure at 0.3MPa, heating air flux at 65 m3/h, temperature at 270℃, feed flux at 11 L/h. A test system was built to investigate the mesoscopic spray performance of the two-fluid nozzle. It was found that the optimum working condition is liquid pressure at 0.1 MPa and gas pressure at 0.2 MPa. In addition, the higher liquid temperature is, the smaller brine average diameter is; brine s alinity has little effect on atomization.3. A set of parabolic trough solar collector device was designed, and the performance of it was investigated. The parabolic relationship between air flux and solar collector efficiency was fitted, and it was proved to be feasible by error analysis.4. A mesoscopic spraying evaporation system integrated with a set of parabolic trough solar collector device was built, in which brine can be condensed from 146.79 g/L to 351.88 g/L under the optimum operating condition. Compared with system powered by electric energy, the power consumption in mesoscopic spray evaporation system with solar collector was saved approximately 70% under the same condition that both two systems operated for eight hours in one day. In addition, the system was optimized through Colebrook White equation, which revealed that the power consumption could be further reduced.更多还原