| Title |
The Effects of the Installation Conditions of Ground Loop Heat Exchanger to the Thermal Conductivity and Borehole Resistance |
| Authors |
임효재(Hyo Jae Lim) ; 공형진(Hyoung Jin Kong) ; 강성재(Sung Jae Kang) ; 최재호(Jae Ho Choi) |
| Keywords |
지중열교환기 ; 지중 유효 열전도도 ; 열응답 시험 ; 열 저항 Ground loop heat exchanger ; Ground effective thermal conductivity ; Thermal response test ; Thermal resistance |
| Abstract |
A ground loop heat exchanger in a ground source heat pump system is an important unit that determines the thermal performance of a system and its initial cost. A proper design requires certain site specific parameters, most importantly the ground effective thermal conductivity, the borehole thermal resistance and the undisturbed ground temperature. This study was performed to investigate the effect of some parameters such as borehole lengths, various grouting materials and U tube configurations on ground effective thermal conductivity and borehole thermal resistance. In this study, thermal response tests were conducted using a testing device to 9 different ground loop heat exchangers. From the experimental results, the length of ground loop heat exchanger affects to the effective thermal conductivity. The results of this experiment shows that higher thermal conductivity of grouting materials leads to the increase effective thermal conductivity from 22 to 32%. Also, mounting spacers have increased by 14%. |