LNG 냉열을 회수하기 위해 재킷 냉각수를 열원으로 하는 유기랭킨사이클의 열교환기 설계

Abstract

In this study, the thermal design of the evaporator and condenser in the ORC system using the jacket cooling water as the high temperature heat source and the cooling heat of LNG as the low temperature heat source was carried out. R134a was used as the working fluid for the ORC system. In the case of the evaporator, Shah"s correlation shows the lowest heat transfer coefficient among the two-phase flow heat transfer coefficients in tubes obtained from the literature. It was found that the contribution of nuclear boiling in the low quality region was dominant. Kandlikar"s correlation also showed the contribution of nuclear boiling. As the quality is increased, the contribution of convective evaporation was not significant. Lim"s correlation showed the highest heat transfer coefficient, and the contribution of nuclear boiling in the whole quality region was not as large as that of convective evaporation. Therefore, the total heat transfer surface area of the evaporator was the highest when obtained from Shah"s correlation. Low value was obtained when obtained from the correlation of Lim. In the condenser, the shell-side heat transfer coefficient obtained from Nusselt analysis was the lowest, followed by Kern and Eissenberg. The heat transfer surface area of the condenser showed the highest when obtained from Nusselt analysis.