Title: Exergy analysis of an inter-city bus air-conditioning system

Authors: E. Tosun; M. Bilgili; G. Tuccar; A. Yasar; K. Aydin

Addresses: Engineering and Architecture Faculty, Department of Mechanical Engineering, Cukurova University, P.O. Box 01330, Adana, Turkey ' Ceyhan Engineering Faculty, Department of Mechanical Engineering, Cukurova University, P.O. Box 01950, Adana, Turkey ' Faculty of Engineering and Natural Sciences, Department of Mechanical Engineering, Adana Science and Technology University, P.O. Box 01180, Adana, Turkey ' Ceyhan Engineering Faculty, Department of Mechanical Engineering, Cukurova University, P.O. Box 01950, Adana, Turkey ' Engineering and Architecture Faculty, Department of Automotive Engineering, Cukurova University, P.O. Box 01330, Adana, Turkey

Abstract: In this paper, exergy analysis was implemented to improve the inter-city bus air-conditioning (AC) system design. Firstly, an inter-city bus with a passenger capacity of 56 people was selected and then its hourly cooling load capacity was determined with the help of cooling load hourly analysis program (HAP). Analyses were performed for different air mixing ratios (MRs) and seasons. Coefficient of performance (COP), exergy efficiency (ψ) and exergy destructions (Ėxdest) of whole system and its each sub-units were evaluated. Results demonstrated that the atmospheric air temperature and air MR substantially affect the inter-city bus AC systems' performance. According to the results obtained for July, when air MR is 0.5, maximum exergy destruction value was calculated as 6.96 kW at compressor. Exergy destruction values were computed as 2.78, 2.61 and 0.99 kW for evaporator, condenser and expansion valve, respectively.

Keywords: exergy efficiency; intercity buses; air conditioning; exergy destruction; COP; coefficient of performance; air mixing ratio; cooling load capacity; isentropic efficiency; thermal transmittance; psychometric diagram; sensible heat gains; latent heat gains; evaporator; condenser; expansion valve.

DOI: 10.1504/IJEX.2016.078094

International Journal of Exergy, 2016 Vol.20 No.4, pp.445 - 464

Available online: 27 Jul 2016 *

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