【作者】 贾春霞；

【导师】 吴静怡； 代彦军；

【作者基本信息】 上海交通大学 ， 制冷及低温工程， 2006， 博士

【摘要】 干燥剂除湿具有传质效率高、可用余热、太阳能低位热能驱动等突出优点,在室内环境湿度控制、工业干燥等场合有广泛用途。然而传统干燥剂存在吸湿量小、性能不够稳定以及再生要求相对较高等问题。本文研制了一种动态吸湿量大、再生容易、性能稳定的由硅胶和卤素盐(氯化锂)组成的新型复合干燥剂,可有效利用低位余热、太阳能等热源。论文确定了复合干燥剂的强制液解工艺过程,得到了复合干燥剂不发生液解的最佳成份配比,解决了困扰复合干燥剂应用的液解问题。实验测量了复合吸附剂和常用干燥剂(包括硅胶和沸石分子筛13X)在典型温度(25℃、35℃、40℃)下的空气吸水等温线,结果表明复合吸附剂的吸湿能力比常用吸附剂(如硅胶)的高出67%～145%。分析复合干燥剂的成份、孔隙结构、等温线类型以及吸附热等,提出了复合干燥剂—水分平衡吸附模型。揭示了硅胶基复合干燥剂材料基于物理吸附与化学吸附耦合作用的强化吸湿机理。论文提出了陶瓷基除湿转轮复合干燥剂浸渍和附着方法,制作了采用新型复合干燥剂材料的除湿转轮,设计搭建了干燥剂转轮除湿器除湿特性测试台,对干燥剂转轮除湿器的动态、稳态除湿特性进行了实验分析,并与常规转轮进行了对比。实验结果表明,在相同的气候条件下,复合干燥剂转轮的最佳再生温度低于硅胶转轮,而且除湿量比同规格的硅胶转轮提高了50%。在低湿的气候条件下,复合转轮的除湿优势更加明显。特别发展了陶瓷基干燥剂转轮除湿器数学模型,并进行了实验验证。在此基础上分析了除湿转轮各参数对转轮最优转速的影响,指明强化转轮传热、传质过程的途径。论文设计搭建了潜热、显热分级处理、应用新型干燥剂转轮除湿器的复合空调系统实验台,对复合除湿空调潜热传递规律和节能特性进行了理论分析与实验研究,揭示了利用新型干燥剂转轮除湿装置潜热、显热分级处理的空调流程的优越性和节能潜力,并围绕性能指标进行了优化。更多还原

【Abstract】 Desiccant dehumidification has high mass transfer efficiency. It can make use of low-grade heat energy as driving force, such as waste heat and solar energy. Furthermore it also can be applied in the following fields, for example humidity control, industry desiccant and so on. However traditional desiccant has smaller dynamic adsorption amounts, unstable dehumidification performance, and it needs high temperature to regenerate the conventional desiccant. In this paper a composite desiccant with bigger dynamic adsorption amounts, stable dehumidification performance and low regeneration temperature is developed. The new composite desiccant is composed of silica gel and lithium chloride. The lyolysis puzzled the application of composite desiccant. In this paper the craft of forced lyolysis is determined. Furthermore the lyolysis is avoided and the optimal mixture ratio of the composite desiccant is obtained. SEM-EDAX, ASAP2010 and dynamical mechanics/differential thermal analyzer are used to character the composite desiccant. The reinforce adsorption mechanism of composite desiccant is explored based on the couple of physics adsorption and chemical adsorption. The adsorption isotherm of composite desiccant and traditional desiccants (silica gel and 13X molecular sieve) are measured under the classic temperature (25℃、35℃、and 40℃). The experimental results indicate that adsorption capacity is higher than that of silica gel by about 67%～145%. This paper analysis the type of isotherm adsorption, adsorption heat and pore structure for composite desiccant. A water vapor equilibrium adsorption model of composite desiccant is put forward.The dipping and adhesion method of composite desiccant wheel is raised in this paper. A new composite desiccant wheel is made and experimental equipment of desiccant wheel is built up. The dynamic and steady dehumidification performance of the desiccant wheels are measured and compared with traditional silica gel wheel by means of the experimental equipment. The experimental results reveal that the optimal regeneration temperature of composite desiccant is lower than that of silica gel desiccant wheel under the same experimental conditions and the moisture removal amounts is higher than silica gel wheel by 30%~50%. Moreover the dehumidification predominance of the composite desiccant wheel is more obvious under low moisture climate. Especially a mathematical model for composite desiccant wheel based on ceramic is developed and validated by experimental data. On the base of valid model the effects of parameters on the optimal rotation speed are analyzed. These analytic results demonstrate the reinforce approach of heat and mass transfer.Hybrid air conditioner equipment that deals the latent heat and sensible heat separately is designed and established. The transfer rule of latent heat and energy conversion characteristic of the hybrid air conditioner are analyzed theoretically and experimentally. It illuminates the advantage and energy conversion potential of the hybrid air conditioner using the composite desiccant wheel. Moreover the performance is optimized according to the performance index.更多还原