Heat Extraction Analysis of a Novel Multi-tube Borehole Heat Exchanger in Lab Scale

• Main Authors: Cheng, Pao-Yuan, 鄭博元
• Other Authors: Wang, Chi-Chuan
• Format: Others
• Language: en_US
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/98656142549431520964

碩士 === 國立交通大學 === 機械工程系所 === 103 === The research studies on a common borehole heat exchanger applicable in geothermal energy- the common U-tube heat exchanger and the designed co-axial multi-tube heat exchanger. By reducing the size of the heat exchanger, the heat extraction performance of both heat exchangers are tested. The heat exchangers are composed of 4-charge pure copper tubes, with a height of 20 centimetres, the configurations are a u-tube and a coaxial multi-tube heat exchanger. By means of changing the flow rate and well-side temperature, the overall heat resistance, pressure drop, heat transfer rate, free convection coefficient of well-side are examined by recording the pressure and temperature of heat exchanger inlet and outlet. In order to study the flowing pattern on the shell-side of the heat exchanger, the vertical temperature distribution inside the simulated well is examined. Some fouling effects on heat transfer is also tested in the study.