TY - JOUR
DP - National Agricultural Library
DB - PubAg
JO - Renewable energy
TI - Effect of vertical ground temperature distribution on parameter estimation of in-situ thermal response test with unstable heat rate
A1 - Zhang, Changxing
A4 - Zhang, Changxing
A4 - Song, Wei
A4 - Liu, Yufeng
A4 - Kong, Xiangqiang
A4 - Wang, Qing
EP - 2019 v.136
KW - algorithms
KW - heat
KW - heat exchangers
KW - models
KW - renewable energy sources
KW - soil temperature
KW - thermal conductivity
AN - 6292589
AB - This paper proposed a parameter estimation method for identifying ground thermal conductivity and volumetric heat capacity using the Nelder-Mead Simplex search algorithm (NMSA) in in-situ thermal response test (TRT) with unstable heat rate, the duct storage system (DST) model for borehole heat exchanger (BHE) was applied to do with variable heat rate and the vertical ground temperature distribution in initial soil temperature. The parameter estimation was carried out using the in-situ TRT data in Qingdao, and the effect of vertical ground temperature distribution on estimated results was compared and analyzed. The relative error of estimated ground thermal conductivity using the regression temperature fitted by the test temperatures from the 5th m depth to the 120th m depth decreased by about 9.1% than that corresponding to the integral mean temperature calculated by test temperatures from the 5th m depth to the 120th m depth. However, the estimated volumetric heat capacity is hardly sensitive to initial soil temperature, and the relative errors are not higher than 2% no matter how to do with initial soil temperature.
PY - 2019
LA -
DA - 2019-06
VL - v. 136
SP - pp. 264-274
DO - 10.1016/j.renene.2018.12.112
ER -