【作者】 边争；

【导师】 连之伟；

【作者基本信息】 上海交通大学 ， 供热、供燃气、通风及空调工程， 2012， 硕士

【摘要】 基于超声雾化液体除湿的思想,设计出超声雾化液体除湿空调系统,并设计搭建了除湿系统性能测试实验台。采用质量比为1:1的氯化钙、氯化锂混合盐溶液作为除湿剂,实验测定了超声雾化液体除湿空调系统的效率。结果表明,在9种不同实验条件下,该系统的除湿效率约为18.1%~26.9%。实验还分析了盐溶液除湿剂的质量分数、气液反应时间、液气比等关键运行参数对系统性能的影响。结果表明,盐溶液质量分数、气液反应时间、液气比等因素对系统除湿效率有显著的影响。在38%~35%的范围内,随着混合盐溶液质量分数的逐渐减小,超声雾化液体除湿系统的除湿效率逐渐降低。在超声雾化液体除湿空调系统中,延长气液反应时间,可提高除湿效率。在本文实验条件下,系统的液气比仅为0.18~0.84。当液气比由0.18增至0.84时,除湿效率可提高约50%。在本文实验条件下,超声雾化液体除湿空调系统的被处理空气会产生约0.66℃~1.48℃的温升,且除湿效率越高,空气温升越大。采用数学分析的方法分析了各关键运行参数对超声雾化液体除湿空调系统性能的影响,作为系统改进策略的参考。数学分析的结果表明,对本文研究的超声雾化液体除湿系统,当液气比小于1.0时,保持其他运行参数不变,增加液气比值能够显著地提高系统的除湿效率,而当液气比大于1.0时,继续增加液气比对除湿效率的改善不明显。延长气液反应时间能够有效改善超声雾化液体除湿系统的效率,但气液反应时间与液气比会互相影响。经数学计算,当液气比为0.2时完全反应时间为1.6s,而液气比逐渐增大至1.0时,完全反应时间仅为0.3s。增加液气比会增加系统的耗液量,因此在适当的液气比条件下,需通过延长气液反应时间来增加系统效率、降低除湿成本。对于超声雾化液体除湿系统,粒径约50μm的盐溶液雾化颗粒使得除湿过程中的传质系数大大增加,继续减小粒径会增加雾化成本,因此该粒径是超声雾化除湿系统合适的选择。根据以上数学分析的结果,对超声雾化液体除湿空调系统进行了改进,以达到在合理利用建筑空间的同时,有效改善系统性能的目的。此外,在超声雾化液体除湿系统的研究基础上,结合传统的空气式溶液再生器提出了超声雾化液体再生的思想,并对除湿系统和再生系统进行了整合,设计出超声雾化液体除湿/再生系统。该系统能够有效地提高除湿/再生效率,降低系统阻力,减少系统输送能耗,并且合理利用太阳能、工业废热等低品位能源。更多还原

【Abstract】 Based on the conception of dehumidification with liquid desiccant making use of the ultrasound atomization technology, a new kind of ultrasound atomization dehumidifying system with liquid desiccant was designed, and an experiment bench was constructed for the performance analysis of the system. The mixed salt solution of Lithium chloride and Calcium chloride with the mass ratio 1:1 was used as the liquid desiccant in the system. The efficiency of the system was studied by different experiments. It’s found that the dehumidification efficiency of this system is 18.1%~26.9% under 9 groups of experimental conditions. In additional, the effects of quality concentration of calcium chloride and lithium chloride mixture solution, liquid-air ratio and air-liquid reaction time were analyzed according to experimental data. It’s found that the efficiency decreases when the salt quality concentration decreases from 38% to 35%; liquid-air ratio and air-liquid reaction time greatly affect the dehumidification efficiency. Increasing the reaction time helps improve efficiency of the ultrasound atomization dehumidifying system with liquid desiccant. Besides, the efficiency increases 50% when the liquid-air ratio increases from 0.18 to 0.84. Moreover, the temperature of the processed air is raised by 0.66℃~1.48℃when the efficiency increases.Mathematical model was established to predict efficiency of the ultrasound atomization dehumidifying system with liquid desiccant under different conditions. Results from the mathematical analysis could be used for the optimization of the system. It’s found that increasing the liquid-air ratio when it’s less than 1.0 could help improve the performance significantly. Meanwhile, if the value is higher than 1.0, keeping increasing the liquid-air ratio does not work well. Besides, increasing the air-liquid reaction time also improves the efficiency of the dehumidification system. However, relationship between the reaction time and liquid-air ratio is very complicated, and they are affected by each other. Through the mathematical analysis, it’s found that the reaction time is less than 1.6s if the liquid-air ratio is 0.2, but the reaction time could be reduced to 0.3s by increasing the liquid-air ratio to 1.0. However, raising the liquid-air ratio means increasing the consumption of the solution, so increasing the reaction time to improve the performance without increasing the cost of solution is preferred. The mass transfer coefficient during the dehumidifying process is increased by atomizing the liquid desiccant into droplets with the diameter about 50μm, which is appropriate for the ultrasound atomization dehumidifying system with liquid desiccant.An optimized ultrasound atomization dehumidifying system with liquid desiccant was designed according to the results of the mathematical analysis, of which the dehumidification efficiency is improved and the space utilization is more reasonable.At last, based on the research of ultrasound atomization dehumidifying system, a liquid desiccant regenerating system was proposed by optimizing traditional regenerator. The ultrasound atomization dehumidifying and regenerating system was designed, of which the dehumidification and regeneration efficiency is improved, and the energy consumption is lower by reducing the system resistance. Besides, the solar energy and industrial waste heat could be used in this ultrasound atomization dehumidifying and regenerating system.更多还原