Research Information System
Thesis Type: Doctorate
Institution Of The Thesis: Gazi University, Teknoloji Fakültesi, Enerji Sistemleri Mühendisliği, Turkey
Approval Date: 2021
Thesis Language: Turkish
Student: KERİM MARTİN
Supervisor: Kurtuluş Boran
Open Archive Collection: AVESIS Open Access Collection
Abstract:Heat recovery studies have been among the topics frequently studied by researchers at all times. This issue has become even more interesting in these days when energy resources around the world are at the point of depletion. Considerable energy savings are achieved thanks to waste heat recovery units. In this thesis, an experimental research has been carried out on improving the performance of an air-to-air heat recovery unit containing heat pipes by using 2 different nano fluids. Thermal efficiency, thermal resistance and temperature distributions along the heat pipes are considered as performance indicators. One of the nano fluids used instead of pure water in heat pipes is a hybrid nano fluid prepared with CuO and Fe nanoparticles, and the other is a nano fluid prepared with only CuO nanoparticles. Results were compared according to the Re numbers occurred in the air ducts. Using of the CuO + Fe / Pure Water hybrid nano fluid has ensured higher efficiency and recovery rates compared to other fluids. The highest efficiency value was reached as 28.2% under the condition that CuO + Fe / Pure Water nano fluid was used, the cold channel Re number was 7000 and the hot channel Re number was 16600. The highest recovery rate was also obtained as 86.8% in the experiment using this fluid. In this condition, the cold and hot duct Re numbers were 12300 and 10550, respectively. In terms of reducing the evaporator temperature and thermal resistance of the heat pipes, CuO + Fe / Pure Water was the best again. CuO / Pure Water came after CuO + Fe / Pure Water. In this thesis, the system was modelled in 2 dimensions in ANSYS Fluent 19 program and a numerical solution was also obtained. Thermal efficiency values obtained in numerical analysis were lower than experimental results. There were differences between the two analyses with values varying between 2% and 13.1%. This range is in the acceptable range in the literature