热泵驱动的中空纤维膜液体除湿系统的热力学与动力学特性

Membrane-based liquid desiccant air dehumidification is highly desired in HVAC industry because it can overcome the problem of liquid droplet cross over existed in traditional direct-contact liquid desiccant air dehumidification systems. In this project, a heat pump driven hollow fiber membrane based liquid desiccant air dehumidification system is proposed. It uses a hydrophobic-hydrophilic composite membrane to realize non-contacting air dehumidification. The problem of droplets cross over is prevented. It uses a heat pump to realize salt solution heating/regeneration and cooling/absorption. Thus the Coefficient of Performance (COP) is improved. In this project, the thermodynamic and dynamic performances of the system and the transport properties in the membrane module will be investigated. The research content includes: to set up the static and dynamic thermodynamic models of the system, to disclose the influences of operating conditions and design parameters on system efficiencies, to clarify the relations of energy matching between various components, to disclose the energy saving theories. The investigation also includes: to set up the coupled heat and mass transfer model of the "liquid-membrane-gas" system in the membrane module; to know the transport dynamics of the membrane module, to disclose the fluid flow and heat and mass transfer mechanisms of the hollow fiber membrane module under trasitional flow regime; to clarify the intensification mechanisms of transport phenomena; to analyze the static and dynamic behaviors of the system, to study the thermodynamic and dynamic optimization theories of the system by extreme optimization algorithm. All these efforts will build up the fundamentals of the system for future industrialization.

膜式液体除湿技术可克服传统直接接触式液体除湿技术存在带液飞沫污染的弊端，在室内环境控制领域有重大需求。本项目提出一种热泵驱动的中空纤维膜液体除湿系统，它采用一种亲水/憎水复合膜将处理空气与吸湿盐溶液隔开，避免空气带液飞沫污染。它采用热泵实现吸湿溶液的加热再生与冷却吸收，提高了系统能源利用效率。项目将对该系统的热力学特性和中空纤维膜组件的传递动力学特性开展研究，所涉及的内容包括：建立系统的稳态和动态热力学模型，认识各种操作和设计条件对系统效率的作用机理，阐明各部件能量负荷匹配关系，揭示系统节能原理；建立膜组件中"液－膜－气"体系的热质耦合传递动力学模型，用分形理论揭示随机分布的中空纤维膜管束在过渡流状态下的流动与传递规律，阐明组件传递强化机理；分析系统静态与动态特性，对所建立的模型进行极值优化，研究系统热力学与动力学优化原理。上述研究将为该系统今后的实用化研究打下理论基础。

膜式液体除湿技术可克服传统直接接触式液体除湿技术存在带液飞沫污染的弊端，在室内环境控制领域有重大需求。本项目提出了一种热泵驱动的中空纤维膜液体除湿系统，它采用一种亲水/憎水复合膜将处理空气与吸湿盐溶液隔开，避免了空气带液飞沫污染。它采用热泵实现吸湿溶液的加热再生与冷却吸收，提高了系统能源利用效率。项目首先对该系统的热力学特性和中空纤维膜组件的传递动力学特性开展研究，建立了系统的稳态和动态热力学模型，研究了各种操作和设计条件对系统效率的作用机理，阐明各部件能量负荷匹配关系，揭示了系统节能原理。其次建立了膜组件中"液－膜－气"体系的热质耦合传递动力学模型，特别是研究了斜向冲刷管束的热质交换规律，阐明了实际流动工况下组件的传递强化机理。上述研究为该系统今后的实用化研究打下理论基础。