نوع مقاله : مقاله پژوهشی
نویسندگان
1 پردیس دانشکده های فنی- دانشگاه تهران
2 پردیس دانشکده های های فنی - دانشگاه تهران
3 مرکز تحقیقات ساختمان و مسکن
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
In this study, the heat transfer properties of R-134a under convective boiling conditions in horizontal microfinned flattened tubes were investigated. Microfinned copper tubes with outer diameter of 9.52 mm were flattened into oblong shapes with different internal heights of 6.6, 5.5, 3.8 and 2.8 mm. The experimental set-up used in this investigation was a well instrumented vapor compression refrigeration cycle. It consisted of a test evaporator, on which all experiments were carried out. In addition, there was a pre-evaporator to achieve the required vapor qualities. A post-evaporator was used to superheat the fluid before entering the compressor. The refrigerant which flows inside the tube of evaporators is electrically heated by an electrical coil wrapped around it.The experiments were carried out for mass velocities from 74 to 107 kgm
کلیدواژهها [English]