Development and evaluation of transfer functions for a variable speed compressor
Küçük Resim Yok
Tarih
2012
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
In this study, transfer functions of electronic expansion valve and variable speed scroll compressor in a chiller system are developed based on an experimental analysis. Dynamic behaviours of water temperature at chiller output and refrigerant superheat at evaporator outlet have either the first- or the second-order linear models, respectively. Different from the existing modelling studies in literature novel models are presented for variable speed refrigeration system with scroll compressor and liquid type evaporator. The scroll compressor used in the current study is not produced for variable speed operation however it is operated with some limitations in the range of 30 to 50 Hz through an inverter. Similar restrictions are presented for the electronic expansion valve as 10 per cent to 35 per cent opening range because of operational limitations. To validate transfer functions of the variable speed scroll compressor and electronic expansion valve, mean square error values for all transfer functions are calculated. The mean square error values vary between 0.0126 and 0.3116. In addition, all transfer functions are designed and tested using corresponding proportional-integral-derivative controllers in order to see their applicability. The results indicate that energy savings are a consequence of operating the chiller at smaller frequencies than the basic 50 Hz while partial load occurred. © Authors 2011.
Açıklama
Anahtar Kelimeler
chiller, control, modelling, refrigeration, transfer function, variable speed
Kaynak
Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering
WoS Q Değeri
Scopus Q Değeri
Q3
Cilt
226
Sayı
3
