Journal of ILASS-Korea (한국분무공학회지)

Institute for Liquid Atomization and Spray Systems-Korea (한국분무공학회)
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Experimental Validation on Performance of Waste-heat-recovery Boiler with Water Injection

물분사 폐열회수 보일러의 효용성에 대한 실험적 검증

  • 신재훈 (인하대학교 대학원 기계공학과) ;
  • 박태준 (인하대학교 대학원 기계공학과) ;
  • 조현석 (인하대학교 수소기반 기계시스템 연구단) ;
  • 유준상 (인하대학교 수소기반 기계시스템 연구단) ;
  • 문석수 (인하대학교) ;
  • 이창언 (인하대학교)
  • Received : 2023.02.16
  • Accepted : 2023.03.06
  • Published : 2023.03.31
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Abstract

The waste-heat-recovery boiler with water spray (HR-B/WS) applies the heat exchange between the inlet air and exhaust gas with the water spray into the inlet air. The evaporation of water in the inlet air promotes heat recovery from the exhaust gas so that thermal efficiency can be improved by the enhanced condensing effect. The NOx emission can also be reduced by lowering the flame temperature due to the dilution effect of the water. In this study, the validity of this concept is examined by the practical boiler test performed with a 24 kW condensing boiler under the full load condition according to the water injection amount. The theoretical amount of water injection is calculated under the assumption of full evaporation of the sprayed water, which is calculated as 50 g/min. Since the injected water cannot evaporate fully in the actual system, the maximum water spray amount is set as 100 g/min. The results showed that the water injection can increase the thermal efficiency up to 95.59% and reduce NOx and CO emissions simultaneously to 8.9 ppm and 35 ppm at 0% of O2. Although the heat energy loss increased due to the unevaporated water, the increase in water injection amount caused higher thermal efficiency due to the increased amount of the evaporated water.

Keywords

Acknowledgement

본 논문은 2020년도 산업통상자원부 및 산업기술평가관리원(KEIT) 연구비 지원에 의한 연구임(과제번호: 20010957).

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