An analysis of the thermodynamic efficiency for exhaust gas recirculation-condensed water recirculation-waste heat recovery condensing boilers (EGR-CWR-WHR CB)

• Published in: Energy (Oxford) 2015-06, Vol.86, p.267-275
• Main Authors: Lee, Chang-Eon, Yu, Byeonghun, Lee, Seungro
• Format: Article
• Language: English
• Subjects: Boilers; Computational efficiency; Computing time; Condensed water recirculation (CWR); Condensing; Condensing boiler (CB); Exhaust; Exhaust gas recirculation (EGR); Gas temperature; Heat recovery; Thermodynamic efficiency; Waste heat recovery (WHR)
• ISSN: 0360-5442
• DOI: 10.1016/j.energy.2015.04.042

This study presents fundamental research on the development of a new boiler that is expected to have a higher efficiency and lower emissions than existing boilers. The thermodynamic efficiency of exhaust gas recirculation-condensed water recirculation-waste heat recovery condensing boilers (EGR-CWR-WHR CB) was calculated using thermodynamic analysis and was compared with other boilers. The results show the possibility of obtaining a high efficiency when the temperature of the exhaust gas is controlled within 50–60 °C because water in the exhaust gas is condensed within this temperature range. In addition, the enthalpy emitted by the exhaust gas for the new boiler is smaller because the amount of condensed water is increased by the high dew-point temperature and the low exhaust gas temperature. Thus, the new boiler can obtain a higher efficiency than can older boilers. The efficiency of the EGR-CWR-WHR CB proposed in this study is 93.91%, which is 7.04% higher than that of existing CB that is currently used frequently. •The study presents the development of a new boiler expected to have a high efficiency.•Thermodynamic efficiency of EGR-CWR-WHR condensing boiler was calculated.•Efficiency of EGR-CWR-WHR CB is 93.91%, which is 7.04% higher than existing CB.