• The Magazine for Energy Service Companies
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• s.25
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• pp.40-51
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• 2003

• The Magazine for Energy Service Companies
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• s.33
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• pp.24-29
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• 2005

• The Magazine for Energy Service Companies
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• s.37
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• pp.22-25
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• 2005

KCC 여천공장은 석고보드를 생산하고 있다. 대표적인 에너지 다소비업종인 화학산업 KCC 여천공장은 에너지절감이 곧 가격경쟁력 확보라는 생각으로 다양한 에너지절감 활동을 펼치고 있었다. 폐열회수기 ESCO사업과 자체 에너지절감사업등을 통해 에너지절감에 힘쓰는 KCC 여천공장을 찾았다.

• The Magazine for Energy Service Companies
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• s.16
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• pp.28-29
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• 2002

에너지관리공단 등과 연대하여 공동주택의 폐열회수기 설치 및 고효율조명기기 교체운동을 펼쳐 공동주택 입주민들의 관리비절감 효과를 상승시키는 것은 물론이고 입주민 상호간에 신뢰 구축 및 살기좋은 아파트 만들기에 저희 협회가 구심체 역할을 해나갈 예정입니다.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.21 no.5
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• pp.282-290
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• 2009

A ceramic monolith heat exchanger is studied to find the performance of heat transfer and pressure drop by numerical computation and $\xi$-NTU method. The numerical computation was performed throughout the domain including fluid region in exhaust gas-side rectangular ducts, ceramic core and fluid region in air-side rectangular duct with the air and exhaust in cross flow direction. In addition, the heat exchanger was also analyzed to estimate the performance by conventional $\xi$-NTU method with several Nusselt number correlations for flow in rectangular duct from literature. By comparisons of both performances by the numerical computation and the $\xi$-NTU method, the effectiveness by $\xi$-NTU method was closest to the result by numerical computation within a relative error of 2.14% when Stephan's Nusselt number correlation was adopted to the $\xi$-NTU method among the several correlations.

• Proceedings of the SAREK Conference
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• 2006.11a
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• pp.3-3
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• 2006

• Proceedings of the SAREK Conference
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• 2007.06a
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• pp.68-68
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• 2007

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.21 no.11
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• pp.613-620
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• 2009

The thermal stresses of a ceramic heat exchanger were analyzed numerically since the ceramic material is good in heat resistance but weak in the thermal stress. The analysis of thermal stress was conducted in the ceramic core with two boundary conditions depending on bolt jointing. The thermal stresses were computed by applying temperature and pressure distributions obtained from the numerical results of conjugate heat transfer to ANSYS WORKRBENCH. When number of bolt joining halls was reduced from $8\times2$ to $4\times2$, the maximum principal stresses decrease by 47.6~50.5% and increase in safety factors by 2.18~2.5 for ultimate tensile strength. Thus, it can be said that bolt joining halls should be minimized in ceramic heat exchanger to be efficient in reducing thermal stress. In addition, the width of particular gas flow passages were revised from 52 mm to 42 mm to reduce maximum thermal stresses since certain passages experienced high thermal stresses. From the revision, safety factors were increased by 13.8~14.1% for the boundary condition of $4\times2$ bolt joining halls. Therefore, it is suggested that thermal stress can be reduced by changing local geometry of a ceramic heat exchanger.

• Journal of the Korean Solar Energy Society
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• v.31 no.4
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• pp.9-18
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• 2011

This study assessed the performance of a compact heat exchanger with staggered tube banks for recuperation of high temperature exhaust thermal energy for SOFC fuel cell system. The compact heat exchanger in this study is two pass system which consists of $315{\times}202.5{\times}48.5mm^3$ and 132 tubes of $6.0mm{\Phi}$ for each heat exchanger. From experiments of the 2 pass heat exchanger system, air temperature was increased from $60{\sim}85^{\circ}C$ to $402{\sim}482^{\circ}C$ while gas temperature was decreased from $600^{\circ}C$ to $305{\sim}402^{\circ}C$ according to mass flow rates of 3.9~7.8 g/s. The experimental heat transfer rates of the heat exchanger were compared with CFD numerical solutions with the conventional ${\xi}-NTU$ method. From the comparisons, the following conclusions were obtained. For the heat exchanger system, the relative errors of heat transfer rate by CFD solution were from 7.1 to 27%, and those by ${\xi}-NTU$ method were from 0.6% to 21% compared with experimental data. From the comparisons, it can be said that both of CFD and ${\xi}-NTU$ method almost simulated to experimental data except specific conditions. Pressure drops through air tubes and gas passages were calculated with both of the CFD computation and head loss equations. The differences between them were from 14 to 22%.