DOI QR코드

DOI QR Code

A Study on the Effects of Etching Surface Characteristics on Condensation Heat Transfer in Pre-heating Exchanger

급기 예열 열교환기에서 에칭 표면 특성이 응축 열전달에 미치는 영향에 관한 연구

  • Seok, Sungchul (Dept. of Mechanical Engineering, Graduate School of Kookmin University) ;
  • Hwang, Seung Sik (Dept. of Mechanical Engineering, Graduate School of Kookmin University) ;
  • Choi, Gyu Hong (Dept. of Mechanical Engineering, Graduate School of Kookmin University) ;
  • Shin, Donghoon (Dept. of Mechanical Engineering, Graduate School of Kookmin University) ;
  • Chung, Tae Yong (Dept. of Mechanical Engineering, Kookmin University)
  • 석성철 (국민대학교 대학원 기계공학과) ;
  • 황승식 (국민대학교 대학원 기계공학과) ;
  • 최규홍 (국민대학교 대학원 기계공학과) ;
  • 신동훈 (국민대학교 대학원 기계공학과) ;
  • 정태용 (국민대학교 기계공학과)
  • Received : 2014.01.06
  • Accepted : 2014.05.28
  • Published : 2014.06.30

Abstract

In order to improve the heat efficiency of the general residential boiler, we performed an experiment of condensation heat transfer to air pre-heating exchanger adhered to the condensing boiler. In this study, surface roughness was imposed on the surface of stainless steel by etching. And in order to evaluate the heat transfer performance on each plate, the counter flow heat exchanger fabricated with polycarbonate in used. As a result, on etching treated plate's overall heat transfer coefficient is higher than the original plate. And etching treated plate during 60 seconds with etchant is the to average 15% compared to bare stainless steel. And we studied the heat transfer enhancement factor through the analysis of surface characteristics using AFM.

일반 가정용 보일러의 열효율을 증진시키기 위해서 콘덴싱 보일러에 부착되는 급기 예열 열교환기의 응축 열전달에 대한 실험을 수행하였다. 본 연구에서는 스테인리스의 표면에 대하여 에칭을 이용하여 표면 거칠기를 부과하였다. 그리고 열전달 성능 평가를 위해 대향유동 열교환기를 폴리카보네이트로 제작하였고 원판과 비교 실험을 수행하였다. 그 결과 에칭 처리한 모든 시편의 총괄열전달계수는 원판에 비해 증가하는 것을 확인할 수 있었고, 에칭 시간이 60초인 시편에서 평균 15%까지 증가하였다. 그리고 AFM 장비를 이용하여 표면 특성에 대한 분석을 통하여 열전달 증진 요인에 대해 연구하였다.

Keywords

References

  1. Li Xiao-wei, Meng Ji-an, Li Zhi-xin, "Roughness enhanced mechanism for turbulent convective heat transfer" International Journal of Heat and Mass Transfer, 2011, Vol.54, No9-10, pp.1775-1781 https://doi.org/10.1016/j.ijheatmasstransfer.2010.12.039
  2. J. Nikuradse, "Laws for flow in rough pipes" VDI Forschungsheft 361 4. Series B, 1933
  3. K. Ceylan, G.Kelbaliyev, "The roughness effects on friction and heat transfer in the fully developed turbulent flow in pipes" Appl. Therm. Eng.23, 2003, pp.557-570 https://doi.org/10.1016/S1359-4311(02)00225-9
  4. Jaehyeok Heo. Rin Yun. Yongtaek Lee. Yongchan Kim., "Condensation Heat Transfer Characteristics of R-134a with Wall Thickness and Surface Roughness on Stainless Steel Horizontal Plain Tubes" Trans. of the KSME(B), 2006, Vol.30, No.12, pp.1203-1210 https://doi.org/10.3795/KSME-B.2006.30.12.1203
  5. Ahn S.W, Son K.P, "Effects of Rib Geometries on the Friction Factors and Heat Transfer in the Channel", Trans. of the KSME(B), 2001, Vol.2, No.2, pp.241-247
  6. V. Simonis, P. Poskas, V. Ragaisis, "Enhancement of heat transfer and hydraulic drag in gas-cooled helical channels with artificial roughness on convex wall", Nuclear Engineering and Design, 2012, Vol.245, pp.153-160 https://doi.org/10.1016/j.nucengdes.2012.01.026
  7. A. Garcia, J.P. Solano, P.G. Vicente, A. Viedma, "The influence of artificial roughness shape on heat transfer enhancement : Corrugated tubes, dimpled tubes and wire coils", Applied Thermal Engineering, 2012, Vol.35, pp.196-201 https://doi.org/10.1016/j.applthermaleng.2011.10.030
  8. Frank P.Incropera, David P.DeWitt, Theodore L.Bergman, Adrienne S.Lavine, "Introduction to Heat Transfer" WILEY, 2012, pp.698-737.