Efficient use of energy sources are one of the main focus item in recent researches. The continous increase in energy usage and demand lead researchers and scientists to diversify renewable sources. One of most substantial renewable energy is geothermal energy where main consumption areas are conventional housing, tourism, agriculture and industry. In todays technology, every aspect of geothermal sources are being used. These sources are generally called as low temperature field if between 20-70 ºC, medium temperature field at 70-150 ºC, high temperature field if above 150 ºC. After 135 ºC ground water is being used in circle, residual water temperature is being reduced to about 80 ºC. This study is focused on to increase temperature of tap water which is around atmosphere temperature (~20 ºC) to more utilizable temperatures (~35 ºC) at faucet by using residual water in a heat exchanger. ANSYS-Fluent FEA software has been used to design a U-type, cross flow, 10 mm and 20 mm in diameter double pipe system. 80 ºC water flows through inner while 20 ºC tap water through outer tube and the heat exchanger provides a 35 ºC tap water which is more usable in house appliances. To compare accuracy of FEA results, theoretical convection heat transfer coefficients are calculated with various nusselt numbers from literature studies and cross-checked with calculated coefficient in ANSYS. Thereby analysis results are justified to be correct. Besides required pump power has been calculated to keep continuous flow loop at heat exchanger.
Anahtar Kelimeler: Hairpin heat exchanger, Double pipe system, FEA (Finite Element Analysis), Heat transfer coefficient, Cross flow
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