Enhanced Heat Transfer Characteristics of Graphite Concrete and Its Application in Energy Piles

Table 4

Total thermal resistance for different pipe configurations (mKW⁻¹).

Environmental temperature	0% graphite	5% graphite	10% graphite	15% graphite	25% graphite
U shape	0.401	0.411	0.395	0.381	0.328
W shape	0.377	0.386	0.372	0.360	0.314
Double U shape	0.368	0.376	0.364	0.352	0.308