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dc.contributorDepartment of Building Services Engineeringen_US
dc.contributor.advisorDeng, Shiming (BSE)en_US
dc.contributor.advisorYan, Huaxia (BSE)en_US
dc.contributor.advisorFang, Guanyu (BSE)en_US
dc.creatorJiao, Yizhou-
dc.identifier.urihttps://theses.lib.polyu.edu.hk/handle/200/10874-
dc.languageEnglishen_US
dc.publisherHong Kong Polytechnic Universityen_US
dc.rightsAll rights reserveden_US
dc.titleNovel fuzzy logic controller and comparative study among fuzzy logic control, on-off control and proportional-integral control in a direct expansion air conditioning systemen_US
dcterms.abstractThis dissertation introduces a fuzzy logic control algorithm to replace the traditional on-off control algorithm which is widely applied by the direct expansion (DX) air conditioning (A/C) systems. The fuzzy logic control (FLC) law based variable speed technology enables both the compressor and the supply air fan in a DX A/C system to be continuously operated at a stepless-changed speed under the accurate temperature control. The fuzzy logic control had been proved highly effective in direct expansion air-conditioners in terms of control precision and energy saving. An improved fuzzy logic controller was developed by applying new inherent operating characteristic map containing 64 speed combinations of compressor and fan. Two experiments were conducted with an experimental DX A/C system at a simulated indoor environment, including the disturbance rejection test for fuzzy logic controller and the comparative test for the system controlled by on-off controller, PI controller and fuzzy logic controller. The experimental results indicated that fuzzy logic controller can have the best control performance in terms of control precision, response time, sensitivity and power consumption, and have a robust control stability without being influenced by the setpoint change and load disturbance.en_US
dcterms.extent103, [6] pages : color illustrationsen_US
dcterms.isPartOfPolyU Electronic Thesesen_US
dcterms.issued2020en_US
dcterms.educationalLevelM.Eng.en_US
dcterms.educationalLevelAll Masteren_US
dcterms.LCSHAir conditioning -- Controlen_US
dcterms.LCSHHong Kong Polytechnic University -- Dissertationsen_US
dcterms.accessRightsrestricted accessen_US

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Please use this identifier to cite or link to this item: https://theses.lib.polyu.edu.hk/handle/200/10874