평관에서 순수 및 혼합냉매의 외부응축 열전달 상관식 개발

초록

The condensation of pure and zeotropic refrigerant mixtures on the outside of a smooth tube was studied. Tested refrigerants were R11, R12, R22, R123, R134a, R32, R410A, R407C and R32/R134a, R134a/R123 with different compositions. The HTCs were experimentally determined using a test section composed by a smooth tube at the vapor temperature 39℃ with the wall subcoolings of 3∼8 K. The experimental HTCs of the binary mixtures showed the important effects of GTD and the strong decrease of the HTCs in comparison with the pure fluids data. The measured values of the pure fluids and the different zeotropic mixtures were compared with the correlated data based on nusselt's film theory.