designed a spiral coil PHC energy pile by considering the effective thermal resistance
of the borehole as well as groundwater advection effects ; Xiang et al.
It is observed that with increasing the MWCNTs concentration the polymer matrix, melting temperatures of the fabricated composites are preceded due to the effective thermal resistance
offered by the nanotubes to constraint polymer melting/ flow (30), (31).
The effective thermal resistance for the BHE is defined by Equation 59.
Therefore, if the flow resistances [R.sub.b] and [R.sub.a] are independent of the flow direction, it follows that the effective thermal resistance does not depend on the flow direction.
EFFECTIVE THERMAL RESISTANCE
OF THE INSULATION SYSTEM
Designers of buildings are starting to respond by trying to better predict the heat loss through the building envelope by utilizing procedures outlined in the ASHRAE Handbooks and two-dimensional steady-state heat transfer software to determine the effective thermal resistance
Continuous (e.g., uninterrupted constant thickness insulation systems) can be installed in series with the metal building systems described in this paper, and the effective thermal resistance
can be determined by adding the thermal resistance values of the two systems.
The whole g-function curve does not need to be calculated since only three g-functions values are required for the three effective thermal resistances
. Furthermore, in the proposed approach, the g-functions are not restricted to rectangular equally-spaced bore fields.
The effective borehole thermal resistance is based on three elementary effective thermal resistances
and is given by:
The effective thermal resistances
of these assemblies range from R-16 to R-25 depending on the specific product and the floor details.
Coefficients for the Effective Thermal Resistances
and Capacitances (De Carli et al, 2010) Type [K.sub.1] [k.sub.2] [k.sub.3] [k.sub.4] 1 2 2 - - 2A 2 4 1.5 2 2B 2 4 - - 3 2 6 1 2 4 2 8 - - The energy balance principle is used to analyze the transient heat transfer for a single borehole in a cylinder coordinate system.
[R.sub.y] = effective thermal resistances
for the yearly thermal pulse, m*K/W (h*ft*[degrees]F/Btu)