Energy and exergy analysis on gasoline engine based on mapping characteristics experiment

• Published in: Applied energy 2013-02, Vol.102, p.622-630
• Main Authors: Fu, Jianqin, Liu, Jingping, Feng, Renhua, Yang, Yanping, Wang, Linjun, Wang, Yong
• Format: Article
• Language: English
• Subjects: Applied sciences; Cooling; efficiency; Energy; Energy balance; Energy distribution; Energy grade; Energy management; Energy use; Energy. Thermal use of fuels; Engines and turbines; Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc; Exact sciences and technology; Exergy; Exergy analysis; Fuel consumption; gasoline; Gasoline engine; Gasoline engines; heat; Waste heat; Waste heat recovery
• ISSN: 0306-2619; 1872-9118
• DOI: 10.1016/j.apenergy.2012.08.013

► Exhaust gas energy has higher exergy efficiency than cooling water energy. ► The higher exhaust gas exergy efficiency appears in high-speed and high-load area. ► The higher cooling water exergy efficiency appears in low-speed and low-load area. ► Gasoline engine fuel efficiency can come up to 60% through waste heat recovery. In order to evaluate the energy utilization efficiency of gasoline engine and predict the recovery potential for waste heat energy, energy distribution and waste heat energy characteristics of a naturally aspirated gasoline engine have been studied by combining the methods of energy and exergy analysis. During the research processes, engine energy balance tests were conducted under mapping characteristics, and the parameters required for calculating the energy balance and exergy balance were measured. On this basis, waste heat recovery potential and gasoline engine total exergy efficiency were studied by using the method of exergy analysis. Research results show: at low-speed and low-load, waste heat energy mainly focuses on cooling water; at high-speed and high-load, exhaust gas energy is larger than cooling water energy not only in quantity, but also in exergy percentage and exergy efficiency; the highest exhaust gas exergy efficiency appears in high-speed and high-load area, while the highest cooling water exergy efficiency appears in low-speed and low-load area; theoretically, total fuel efficiency of this gasoline engine can be nearly improved by a time through waste heat recovery, and the maximum total fuel efficiency can reach 60%.