Table 6 Thermal parameters of the fluid, backfill material, inner pipe and outer pipe in the model
From: An efficient hybrid model for thermal analysis of deep borehole heat exchangers
| Circulating fluid | Backfill material | Inner pipe | Outer pipe | |
|---|---|---|---|---|
| Thermal conductivity (W m−1 K−1) | 0.56 | 0.93 | 0.01 | 54 |
| Specific heat capacity (J kg−1 K−1) | 4200 | 1800 | 2300 | 460 |
| Density (kg m−3) | 1000 | 1050 | 1925 | 7930 |
| Kinematic viscosity (N s m−2) | 1.31 × 10−3 | |||
| Dynamic viscosity (m2 s−1) | 1.31 × 10−6 |
