Heffington, "Thermal interference of adjacent legs in a vertical U-tube heat exchanger
for a ground-coupled heat pump," ASHRAE Transactions, vol.
(20 to 25 mm) U-tube heat exchanger
, the thermal resistance of the bore is typically 15% to 25% of the total resistance at design conditions.
For typical borehole and U-tube heat exchanger
designs, 40 elements results in an element size of approximately 0.800 mm.
They considered an equivalent cylinder to replace the U-tube configuration; in particular, they analyzed the single u-tube heat exchanger comparing their results with a finite-element method software.
Moreover, the thermal behavior of enhanced coaxial and double U-tube heat exchangers is investigated by means of measurements.
For this reason, a detailed analysis of the short time-step performance of double U-tube heat exchangers is shown with numerical and analytical models.
Numerical Modeling of the Transient Thermal Interference of Vertical U-tube Heat Exchanger
. College Station, TX: Texas A&M University.
A ground heat exchanger design tool (Spitler 2000) is used to size the vertical U-tube heat exchanger
for given building load profiles.
2006) in the United States confirmed that standing column wells (SCWs) allowed a significant reduction in borehole depth requirement compared with the conventional closed-loop system consisting of arrays of single U-tube heat exchangers
, because of the enhancement of the flow of groundwater into/out of the well by adopting open-ended columns (see Figure 1).
Numerical modeling of the transient thermal interference of vertical U-tube heat exchangers