Abstract
The soil temperature distributions around underground heat exchange pipes were measured on typical models in order to check the results of numerical calculations.The performances of heat storage in the cases of several system were calculated numerically by using the finite difference method. Its variables include: thermal diffusivity of soil and pipe diameter. Calculated results were generalized by the relationship between the dimensionless heat flux and the dimensionless time which is defined by the pipe diameter. This diameter significantly affects the characteristics of heat storage. Consequently, the characteristics of heat storage were discussed in comparison with a straight pipe with infinite space. And the optimum diameter required for the arrangement of under ground pipes was obtained.
