Study On Heat Transfer Characteristics Of Embedded Tubes For Ground Coupled Heat Pumps

The ground source heat pump (GSHP) system makes full use of renewable energy, and boasts the future of protecting the environment and reducing electric power consumption. However, researches on transfer characteristics of the GSHP and system optimization are far from adequate. Further researches are needed.In this thesis, a numerical and linear heat source integrated model (NLIM) was developed by analyzing the unsteady heat transfer of vertical embedded pipes for ground source heat pump, and integrating the merits of the numerical simulation method and finite-length linear heat source model. The replaceable radius in linear heat source model was proposed and its value was given by comparing the values calculated by numerical simulation and Kelvin linear heat source model in this thesis. In order to ensure the precision, the simplified load method applied in the NLIM was amended. So compared with the similar numerical models, the NLIM can simulated the temperature respond underground more quickly with enough precision.Then affect of kinds of factors to the heat transfer of tubes enbeded in Shanghai was analysed by using the results calculated by NLIM. And the proper ranges of the factors, such as velocity of flow, backfill conduction coefficient, were given through analysis.At last, the economy applicability of GSHP was given through ecnonmy analysis of cold and heat source of some buiding in Shanghai.