Table 1. Input parameters.
| Variable | Type | Min. | Max. | Avrg. | Std. | Range | Med |
|---|---|---|---|---|---|---|---|
| X1-Borehole arrangement | Nominal | 1 | 5 | 3 | 1.4144 | 4 | 3 |
| X2-Borehole depth (mm) | Real | 100,000 | 120,000 | 109,950 | 8,155.4 | 20,000 | 110,000 |
| X3-Borehole radius (mm) | Real | 55 | 75 | 65 | 7.1 | 20 | 65 |
| X4-Borehole number | Real | 46 | 56 | 50.956 | 3.9546 | 10 | 50 |
| X5-Vertical spacing (mm) | Real | 4,000 | 5,000 | 4,495 | 409.3 | 1000 | 4,500 |
| X6-Column spacing (mm) | Real | 4,000 | 5,000 | 4,478 | 410.2 | 1,000 | 4,500 |
| X7-Thermal conductivity coefficient (W/(mm ⋅ °C)) | Real | 0.0013 | 0.0028 | 0.002049 | 0.000461 | 0.0015 | 0.002 |
| X8-Nominal external diameter (mm) | Real | 1,000 | 2,000 | 1,499 | 500 | 1,000 | 1,000 |
| X9-U-tube spacing | Nominal | 1 | 4 | 2.498 | 1.1189 | 3 | 2 |
| X10-Temperature (°C) | Real | 10 | 20 | 14.997 | 3.1624 | 10 | 15 |
| X11-Thermal conductivity | Nominal | 1 | 8 | 4.416 | 2.253 | 7 | 4 |
| X12-Circulating liquid parameter | Nominal | 1 | 11 | 5.971 | 3.1683 | 10 | 6 |