| Author: | Tang, Yuhao |
| Title: | Performance analysis of a counter flow liquid desiccant dehumidifier using different packing materials |
| Advisors: | Xiao, Fu (BSE) |
| Degree: | M.Eng. |
| Year: | 2017 |
| Subject: | Hong Kong Polytechnic University -- Dissertations Air conditioning Humidity -- Control Drying agents |
| Department: | Department of Building Services Engineering |
| Pages: | xii, 79 pages : color illustrations |
| Language: | English |
| Abstract: | Liquid desiccant cooling system has been drawn more attention due to its high efficiency and convenient utilization of low-grade heat comparing with conventional air conditioning system. In most cases, conventional air conditioning systems have to cool the air below its dew point to remove the moisture from the air. The evaporator has to operate at low temperature which will lead to the drop of coefficient of performance (COP). The liquid desiccant system handles the humidity individually which makes the whole air conditioning system more efficient. However, the high specific surface area packing material was seldom investigated in liquid desiccant air conditioning. In addition to high specific surface area, performance studies of metal packing material were seldom conducted. Several characteristics of metal packing material make them particularly feasible for liquid desiccant air conditioning system: high structural strength and high thermal conductivity. Therefore, a comparison of three types of packing material can help optimize the design of dehumidifier. In this study, the dehumidification performance of three types of packing materials are investigated in a counter flow dehumidifier using structural packing and lithium chloride solution. The aim of this research is to optimize the liquid desiccant system in Hong Kong. An experimental setup was built to study the liquid desiccant dehumidification performance. The experimental rig includes four parts: dehumidifier part, solution part, air part and measurement part. Three packing materials (fiber, plastics and metal) were tested in various conditions. Results show that the fiber material has higher moisture effectiveness in most cases. In addition, the influence of six inlet parameters on dehumidification performance is compared. The inlet air temperature is of very little concern for whole dehumidification performance. For each packing material, a new empirical equation of moisture effectiveness is developed with essential inlet parameters of air and solution. Three new correlation equations can be used to design the dehumidifier and predict the performance of the liquid desiccant based air conditioning system. The predicted results generated by proposed correlations show good agreement with experimental data. The deviations are within ±20%. This dissertation will help engineers optimize the design of liquid desiccant dehumidifier with different materials. |
| Rights: | All rights reserved |
| Access: | restricted access |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| 991021959948703411.pdf | For All Users (off-campus access for PolyU Staff & Students only) | 2.1 MB | Adobe PDF | View/Open |
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