Experimental investigation and analysis of composite silica-gel coated fin-tube heat exchangers

Desiccant coated heat exchanger provides a promising option for desiccant cooling system, since it can handle sensible load and latent load simultaneously within one component. It is fabricated by coating desiccant material on the surface of conventional fin-tube heat exchanger. In order to enhance the performance of conventional silica gel coated heat exchanger (SGCHE), a novel composite silica gel coated heat exchanger (CCHE) is proposed and fabricated. An experimental setup is built to test and compare the dynamic performance of SGCHE and CCHE. Influences of main operation parameters including water temperatures and inlet air conditions on system performance are analyzed in terms of average dehumidification capacity (D_avg) and thermal coefficient of performance (COP_th). Optimization of cycle switch modes is also discussed. Experimental results show that CCHE has better dehumidification performance compared with SGCHE. In addition, pre-cooling before dehumidification process is found to be advantageous to both D_avg and COP_th.     

Modeling the effect of a superabsorbent polymer material as desiccant in maize drying using CFD

Maize is an important foodstuff in many countries, and one of most susceptible crops to mold and aflatoxin contamination, which results in considerable postharvest losses and is a burden to consumers’ health, especially in developing countries. The timely drying of harvested maize is essential to halt mold development, ensuring safe storage. The effect of the incorporation of a superabsorbent polymer (SAP) as desiccant in a maize dryer was studied using computational fluid dynamics simulations which accounted for heat and mass transfer between maize, SAP and air. The adsorption capacity and adsorption rate of a commercial SAP material were experimentally determined at different temperature and relative humidity levels, which served as basis for the adsorption model required in the simulations. A maize bulk with SAP packages distributed in it was modeled. Results showed that the SAP material increases the drying rate substantially, particularly in the upper bulk zone where the air reaching it is dehumidified the most. The maize closer to the upper bulk surface starts drying from the beginning of the process instead of lagging for hours or days before the drying front reaches it. An inconvenience of the SAP material is the tendency of granules to swell and stick together as moisture reaches a threshold, which may reduce its performance. Thus, provided this issue is resolved or minimized, SAP materials could successfully assist the rapid drying of maize and other crops. They may also be used during storage to avoid rewetting of the crops during periods of high relative humidity.     

凹凸棒石粘土干燥剂的制备与性能研究

本文就利用凹凸棒石粘土制作干燥剂的实验研究作一介绍，通过加入一种或多种改性剂，有效的改善了凹凸棒石粘土的吸湿性能，并且在加入粘结剂制成球形颗粒后仍然能保持较高的吸湿率，吸湿后不变形，具有较高的强度，成本低，无污染，能反复再生使用。     

湿度独立控制空调系统的工程实践

结合实际工程介绍了一个以溶液处理新风实现湿度独立控制的空调系统，对系统的运行情况进行了测试，根据测试结果提出了一种送风含湿量的控制策略。测试结果表明，在室外潮湿的情况下，溶液除湿机组提供的冷量约占所需冷量的50％；在室外相对干燥的情况下，除湿机组提供的冷量约占所需冷量的40％。与传统电压缩制冷系统相比，当电热价比值为3时，湿度独立控制的空调系统可减少20％的运行费用。     

Achievable working range for solid all-desiccant air-conditioning systems under specific space comfort requirements

Solid desiccant air-conditioning systems present a promising solution, in terms of performance level and environmental protection, pointing out their potential to be coupled with thermal solar or waste heat energy source. Nevertheless, these systems are characterized by constraints to the load they can satisfy, through the trade-off between the dehumidification cooling capacity and the latent load of the conditioned space. On that level, one has to note that, for steady environmental conditions, the conditioned space does not present unique value of load, but range of load, corresponding to an array of acceptable temperature and (usually relative) humidity values. In this work a methodology is proposed for the definition of the system's achievable working range under specific set of space (comfort) requirements. Through this approach, the systems present greater potential for covering the space requirements, thus presenting more possibilities on a design basis, and more flexible control strategies, as well. The proposed methodology is presented and discussed through the case study of a solar desiccant air-conditioning system coupled to a typical residential building.     

燃气空调技术概述

本文从经济、技术层面简要介绍了以天然气为一次能源的各种空调技术，包括基本原理、技术特点、设备等。着重介绍了有可能在国内成功推广的天然气发动机驱动技术和相关的复合空调系统。     

转轮除湿器的数学模型及性能研究

建立了转轮除湿器的传热传质数学模型,利用有限差分法对方程组进行离散求解,并编制程序进行模拟,模拟结果与实验数据吻合较好,得到了稳态运行一个周期内空气温湿度和吸附剂温度、吸附率的变化规律及转轮除湿能力的影响因素.     

深圳光明土地储备大厦空调设计

本文介绍了该工程的空调设计,重点介绍了冷热源形式、空调风系统和空调水系统的划分,并对空调设计的节能措施进行了简要的总结和归纳。     

液体干燥剂除湿式燃气空调系统及应用

介绍了液体干燥剂除湿式燃气空调系统的特点及应用。