Heat recovery boilers with water spray. Part I: Thermodynamic analysis validation and boiler practicality

• Published in: Thermal science and engineering progress 2020-08, Vol.18, p.100491, Article 100491
• Main Authors: Lee, Chang-Eon, Kim, Do-Hyun
• Format: Article
• Language: English
• Subjects: Chain-block structure method; Heat recovery boiler; High efficiency; Low NOX emission; Thermodynamic analysis; Water spray
• ISSN: 2451-9049; 2451-9049
• DOI: 10.1016/j.tsep.2020.100491

•Chain-block analysis is convenient for setting up mass and energy balances for each component and overall system.•Thermal efficiency of HR-B/WS is superior to simple HR-B by approximately 6%.•Heat recovery boilers with water spray reduce NOX emission while retaining high efficiency.•Chain-block analysis provides design specification information for all system components. This study develops a thermodynamic analysis method to determine thermal efficiency and provide information regarding capacity design specification for each system component. A chain-block structure analysis method is introduced for heat recovery boilers with water-spray (HR-B/WS), where water is sprayed onto the inlet air stream and/or reaction zone. We subsequently validated the proposed analysis method and investigated the boiler system practically. HR-B/WSs are expected to achieve up to 95% efficiency with reduced NOX emission. Additional water spray onto the combustion chamber may be a useful mechanism to reduce NOX emission while retaining high efficiency when insufficient water is supplied to the heat exchanger.