金属填料型吸收式除湿器的除湿性能研究

通过理论和实验相结合的方式,对金属填料型吸收式除湿器的除湿性能进行了研究,分析和讨论了空气和溶液的进口状态参数对出口状态参数的影响.依据双膜理论建立了该除湿器的传热传质数学模型,并进行了理论研究.实验测试与模拟计算结果表明,溶液的状态参数对除湿器传热传质的影响较大.实验过程中除湿器运行稳定,具有应用的可行性.     

溶液热回收系统研究现状及发展趋势

介绍了溶液热回收系统的工作原理与系统结构。综述了除湿剂、塔填料、空气与溶液传热传质、热质回收塔和释放塔的研究现状及发展趋势。     

膜式液体除湿组件研究综述

膜式液体除湿技术可以有效解决传统气液直接接触除湿器中气液夹带问题。在膜式液体除湿技术中,除湿溶液与空气被防水透气膜隔离,在保证溶液吸收空气中水蒸气的同时,防止溶液渗透到空气中。文中详细综述了现有膜式液体除湿系统研究中所用的除湿溶液,以及其中常用的膜组件,并从理论模型和试验研究两方面分别对在室内配置和室外配置的平板式和中空纤维膜式膜组件的性能展开了分析。最后还对膜式液体除湿组件未来发展方向进行了展望。     

利用蒸发式冷凝器再生除湿溶液时传质系数的实验研究

建立了溶液再生式蒸发冷凝器实验台,利用冷凝热再生氯化锂除湿溶液,对影响空气与除湿溶液之间传质系数的主要因素进行了实验测试.在大量实验数据基础上,分析了除湿溶液质量流速及空气迎面风速对空气与液膜之间传质系数的影响,并回归得到了传质系数的经验公式,为利用低品位热源再生除湿溶液提供理论依据.     

液体除湿器的数值模拟分析

建立了带填充物的液体除湿器的传热传质数值模型,并进行了相应的数值计算。计算结果表明,溶液入口温度和浓度对除湿性能有显著影响,进而影响液体除湿冷却空调的送风温度。     

溶液除湿过程热质交换规律分析

除湿器和再生器是溶液除湿系统的重要传热传质部件。建立了一个测试叉流除湿、再生模块性能的实验台，以溴化锂溶液为除湿剂，用除湿量、除湿效率和体积传质系数描述除湿效果，实验测试了溶液和被处理空气的进口参数对除湿器性能的影响。由实验数据得到的准则关联式，可供叉流除湿器设计参考使用。     

采用吸湿剂处理湿空气的流程优化分析

分析了吸湿剂与空气直接接触的热湿传递过程,得到了溶液与空气热湿传递过程中传热、传湿阻力表达式,比较了溶液-空气不同进口状态的传热、传湿不匹配系数.在溶液进口状态等浓度线上进行的热湿传递过程传热、传湿不匹配系数最小,而等焓线上发生的过程的传热、传湿不匹配系数较大.在构建溶液与空气的热湿处理流程中,应尽可能使除湿与再生过程贴近溶液等浓度线进行.固体吸湿剂与溶液之间的性质差异使得固体吸湿剂与空气间的热湿传递过程一般沿着等焓线发生.     

溶液除湿空调系统中叉流再生装置热质交换性能分析

再生器是溶液除湿空调系统中的重要传热传质部件。搭建了叉流再生器性能测试的实验台,并建立了叉流再生器中传热传质过程的数学模型。以溴化锂溶液为除湿剂,采用总换热量、全热效率描述再生器的热质交换总体效果,采用再生量、再生效率描述传质效果,实验测试了溶液和空气的进口参数对再生器性能的影响,并与逆流再生器的实验结果进行了比较。以实验得到的量纲一传质系数作为数学模型的输入条件,数值计算结果与73组实验数据吻合很好,全热效率和再生效率的偏差均集中在±15%以内。     

溶液除湿方式对室内空气品质影响的初步研究

在溶液除湿空调空气处理过程中，因溶液与空气直接接触，可能对室内空气品质产生负面影响，但同时也可以去除空气中的有害物质。以溴化锂溶液为例，进行了室内空气溴、锂离子的测定，溴化锂溶液对甲醛的吸收实验，除湿溶液对细菌和病毒生长的影响实验，并初步探讨了气液交换模块的除尘作用。     

液体除湿填料塔液体夹带和压降问题研究

分析了填料塔液体夹带量和压降与气流速度和溶液流量的关系,通过实验研究得出了液体夹带量随风机频率和溶液流量的变化关系,提出了解决液体夹带问题的方法。     

Experimental study on dehumidifier and regenerator of liquid desiccant cooling air conditioning system

A new type of air conditioning system, the liquid desiccant evaporation cooling air conditioning system (LDCS) is introduced in this paper. Desiccant evaporation cooling technology is environmental friendly and can be used to condition the indoor environment of buildings. Unlike conventional air conditioning systems, the system can be driven by low-grade heat sources such as solar energy and industrial waste heat with temperatures between 60 and 80 °C. In this paper, a LDCS, as well as a packed tower for the regenerator and dehumidifier is described. The effects of heating source temperature, air temperature and humidity, desiccant solution temperature and desiccant solution concentration on the rates of dehumidification and regeneration are discussed. Based on the experimental results, mass transfer coefficients of the regeneration process were experimentally obtained. The results showed that the mean mass transfer coefficient of the packing regenerator was 4 g/(m² s). In the experiments of dehumidification, it was found that there was maximal tower efficiency with the suitable inlet humidity of the indoor air. The effective curves of heating temperature on the outlet parameters of the regenerator were obtained. The relationships of regeneration mass transfer coefficient as a function of heating temperature and desiccant concentration are introduced.     

液体除湿空调系统国内外研究进展

对液体除湿空调系统、除湿剂、除湿系统中热质交换数学模型的国内外研究进展进行了阐述.     

Similarity of coupled heat and mass transfer between air–water and air–liquid desiccant direct-contact systems

Packed-bed heat and mass transfer devices are widely used in air-conditioning systems, such as cooling tower, evaporative cooler of air–water direct-contact devices, dehumidifier and regenerator of air–liquid desiccant direct-contact devices. Similarities of heat and mass transfer characteristics between air–water and air–liquid desiccant devices are considered and investigated in this paper. Same reachable handling region of outlet air can be obtained for both air–water and air–liquid desiccant devices, which is among three boundary lines, isenthalpic line of inlet air, iso-relative humidity line of inlet fluid (water or desiccant), and the connecting line of inlet statuses of air and fluid. Inlet conditions of air and fluid affect heat and mass transfer characteristics to some extent, so that a zonal method is proposed only according to the relative statuses of inlet air to inlet fluid. Four zones, dehumidification zones A, D and regeneration zones B, C, are divided for air-desiccant direct-contact devices. The first three zones A, B and C are divided for air–water direct-contact devices, with the same zonal properties as those of air-desiccant devices. In order to obtain better humidification performance, fluid should be heated (in zone C) rather than air (in zone B). And fluid should be cooled (in zone A) rather than air (in zone D) to obtain better dehumidification performance. Counter-flow pattern should be applied for best mass transfer performance in the same conditions within the recommended zone A or C, while parallel-flow pattern is the best in zone B or D.     

Performance analysis on the internally cooled dehumidifier using liquid desiccant

Dehumidifier is one of the most important components in liquid desiccant air-conditioning systems. Previous study shows that the internally cooled dehumidifier may have better mass transfer performance than the adiabatic unit. The effect of flow pattern, especially the flow direction of air to desiccant on the internally cooled dehumidifier performance is numerically analyzed in detail. The result shows that counter-flow configuration of air to desiccant has better dehumidification performance, and parallel-flow configuration performs the poorest with the same conditions, due to more uniform mass transfer driving force expressed in the counter-flow configuration. The decrease of the desiccant concentration is the main factor that influences the internally cooled dehumidifier's performance, while the increase of the desiccant temperature is the main performance restricting factor in adiabatic dehumidifier. Internally cooled dehumidifier has better mass transfer performance compared with adiabatic dehumidifier plus external heat exchanger.