물분사 폐열회수 보일러의 효용성에 대한 실험적 검증 = Experimental Validation on Performance of Waste-heat-recovery Boiler with Water Injection

다국어 초록 (Multilingual 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.

참고문헌 (Reference)

1 이창언 ; 김도현 ; 금성민, "물 분사 폐열회수 보일러의 설계 사양을 구하는 열역학적 해석법" 대한기계학회 44 (44): 535-545, 2020

2 신재훈 ; 문석수, "가습연소 폐열회수 보일러의 물분사 설계모델 구축에 관한 연구" 한국분무공학회 26 (26): 96-103, 2021

3 S. Panagiotis, "Water gas shift reaction:research developments and applications" Elsevier 2015

4 M. J. Moran, "Principles of engineering thermodynamics" Wiley 2018

5 D. H. Kim, "Heat recoveryboilers with water spray: Part II: Parametric analysis and optimization of design specifications" 19 : 100643-, 2020

6 C. E. Lee, "Heat recovery boilers with water spray. Part I: Thermodynamic analysis validation and boiler practicality" 18 : 100491-, 2020

7 M. Wei, "Experimental investigation on vapor-pump equipped gas boiler for flue gas heat recovery" 147 : 371-379, 2019

8 K. Murat, "Emissions analysis of an SI engine with humidified air induction" 147 : 235-241, 2018

9 J. Kuck, "Efficiency of vapour-pump-equipped condensing boilers" 16 : 233-244, 1996

10 B. Yu, "Effects of exhaust gas recirculation on the thermal efficiency and combustion characteristics for premixed combustion system" 49 : 375-383, 2013

11 C. E. Lee, "Analysis of the thermodynamic performance of a waste heat recovery boiler with additional water spray onto combustion air stream" 135 : 197-205, 2018