| Author: | Li, Xuejing |
| Title: | Development of an adaptive fuzzy controller for simultaneous indoor air temperature and humidity control using a direct expansion (DX) air conditioning (A/C) system |
| Advisors: | Deng, Shiming (BSE) |
| Degree: | M.Eng. |
| Year: | 2019 |
| Subject: | Hong Kong Polytechnic University -- Dissertations Air conditioning -- Control Humidity -- Control |
| Department: | Department of Building Services Engineering |
| Pages: | xv, 87 pages : color illustrations |
| Language: | English |
| Abstract: | In buildings, to control indoor air humidity at a suitable level is as important as to control indoor air temperature since indoor humidity directly affect people's thermal comfort. Most of previous studies only focused on temperature and thought less about humidity. For example, in hot and humid area like Hong Kong, the time of using A/C system is near seven months every year from March to October. Not only the requirement of removing heat load is high, but also the requirement of removing moisture load is high. Recently, direct expansion air conditioning systems are widely used all over the world since its well control performance, the characteristic of energy-efficient and cost-efficient and the simpler structure. While the performance of controlling humidity was not as well as desired, and then variable-speed direct expansion air conditioning systems were developed which aimed to achieve simultaneous control of indoor air temperature and humidity. It varies the speed of compressor and supply fan which were installed in the air conditioner, and generally, compressor was used to control indoor humidity and supply fan was applied to control the temperature. Furthermore, adaptive fuzzy controller was added to this kind of A/C system which only needed previous studies' and people's experience, while did not need an accurate and complicated mathematical model. The fuzzy control method made simultaneous control of indoor air temperature and humidity became easier. Firstly, this project introduced the basic information of DX A/C system, VS DX A/C system and the requirement of controlling indoor humidity. Secondly, this project did an review of previous controllers of controlling indoor air temperature or both indoor air temperature and humidity. Next, this project introduced fuzzy control and added adaptive fuzzy control to A/C system, and controllability test was carried out to test the controller's performance. |
| Rights: | All rights reserved |
| Access: | restricted access |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| 991022370852503411.pdf | For All Users (off-campus access for PolyU Staff & Students only) | 3.8 MB | Adobe PDF | View/Open |
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