Analysis of Multi-U type Borehole Heat Exchangers for Ground Source Heat Pump System

• Main Authors: Kam-Pang Lai, 黎錦鵬
• Other Authors: Sih-Li Chen
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/xh3ya5

碩士 === 國立臺灣大學 === 機械工程學研究所 === 107 === Ground Source Heat Pump(GSHP) System used Shallow Geothermal Energy to cool down or heat up of buildings, so the heat exchanging between Heat Pump and Shallow Geothermal Energy is important to GSHP’s performance. Here, a multi-U type borehole heat exchanger which uses groundwater as backfilled material and has similar operation mode to the shell-and-tube heat exchanger was designed. This heat exchanger has forced convection of groundwater through shell side to enhances heat exchanging. This study analyze the performance of GSHP combined with multi-U type borehole heat exchanger. This study analyzes the performance of multi-U type borehole heat exchanger with different parameters which included the water flow inside tube, ground water pumping capacity and the distance between the bottom of heat exchanger and the ground water well. The results showed that 92LPM, 73LPM and 1.6m of the water flow inside tube, ground water pumping capacity and the distance between the bottom of heat exchanger and the ground water well respectively are the best parameters for our system. At the best of our system, it showed the cooling coefficient of performance(COP) of GSHP cooling mode is 5.64 and a better cooling performance with 18% higher than conventional water chilling packages, the average heating coefficient of performance(COP) of GSHP heating mode is 4.99 and a better heating performance with 38% higher than conventional heat pump water heaters.This study showed using multi-U type borehole heat exchanger can provide a stable cooling and heating way of GSHP systems, and it can improve Heat Pump’s performance.