دانلود مقاله ISI انگلیسی شماره 146037
ترجمه فارسی عنوان مقاله

مقاله پژوهشی بررسی عددی بر عملکرد گرمادهی حرارت یک سیستم زمین گرمایی مبدل حرارتی پایه

عنوان انگلیسی
Research PaperNumerical investigation on heat extraction performance of a downhole heat exchanger geothermal system
کد مقاله سال انتشار تعداد صفحات مقاله انگلیسی
146037 2018 30 صفحه PDF
منبع

Publisher : Elsevier - Science Direct (الزویر - ساینس دایرکت)

Journal : Applied Thermal Engineering, Volume 134, April 2018, Pages 513-526

پیش نمایش مقاله
پیش نمایش مقاله  مقاله پژوهشی بررسی عددی بر عملکرد گرمادهی حرارت یک سیستم زمین گرمایی مبدل حرارتی پایه

چکیده انگلیسی

The downhole heat exchanger (DHE) geothermal system is commonly used to exploit geothermal energy for space heating. In this paper, a 3D unsteady state numerical model is established to couple fluid flow and heat transfer processes of DHE system. The model is validated by field experimental data. Temperature and velocity fields are analyzed to understand thermal process of DHE system. Heat extraction performances of three different DHE structures, including single U-tube, double U-tube and spiral tube, are compared. Subsequently, cases are studied to investigate how key parameters affect DHE performance. Simulation results depict that spiral-tube has the best heat extraction performance. As working fluid mass flow rate rises, outlet temperature declines and thermal power increases. When inlet temperature ascends, outlet temperature rises while thermal power decreases. Effects of reservoir porosity and tube wall heat conductivity on DHE performance are minor. Higher subsurface water velocity and larger rock heat conductivity can improve DHE performance, but the former has a more significant influence. Besides, subsurface water flow direction has neglected influence on performances of single and double U-tube, but appreciable impact on that of spiral tube. Key findings of this work are beneficial for optimal design and optimization of DHE geothermal system.