functionfiniteLineSource_Equivalent

Finite line source solution of Prieto and Cimmino

Extends from Modelica.Icons.Function (Icon for functions).

Information

This function evaluates the finite line source solution. This solution gives the relation between the constant heat transfer rate (per unit length) injected by a group of line sources of finite length H1 buried at a distance D1 from a constant temperature surface (T=0) and the average temperature raise over a group of N2 lines of finite length H2 buried at a distance D2 from the constant temperature surface. The finite line source solution is defined by:

image

where ΔT1-2(t,r1->2,H1,D1,H2,D2,N2) is the temperature raise over lines in group 2 after a time t of constant heat injection, r1->2 is the list of distance between all pairs of lines in groups 1 and 2, N1->2 is the number of distances, Q' is the heat injection rate per unit length, ks is the soil thermal conductivity and hFLS is the finite line source solution.

The finite line source solution is given by:

image

where αs is the ground thermal diffusivity and erfint is the integral of the error function, defined in Buildings.Fluid.Geothermal.Borefields.BaseClasses.HeatTransfer.ThermalResponseFactors.finiteLineSource_erfint. The integral is solved numerically, with the integrand defined in Buildings.Fluid.Geothermal.Borefields.BaseClasses.HeatTransfer.ThermalResponseFactors.finiteLineSource_Integrand_Equivalent.

Inputs

TypeNameDefaultDescription
Modelica.Units.SI.TimetTime
Modelica.Units.SI.ThermalDiffusivityaSoiGround thermal diffusivity
Modelica.Units.SI.Distance[n_dis]disRadial distance between borehole axes
Integer[n_dis]wDisNumber of occurences of each distance
Modelica.Units.SI.Heightlen1Length of emitting boreholes
Modelica.Units.SI.HeightburDep1Buried depth of emitting boreholes
Modelica.Units.SI.Heightlen2Length of receiving boreholes
Modelica.Units.SI.HeightburDep2Buried depth of receiving boreholes
IntegernBor2Number of receiving boreholes
Integern_disNumber of unique distances
BooleanincludeRealSourcetrueTrue if contribution of real source is included
BooleanincludeMirrorSourcetrueTrue if contribution of mirror source is included

Outputs

TypeNameDefaultDescription
Realh_21Thermal response factor of borehole 1 on borehole 2

Revisions

  • June 9, 2022 by Massimo Cimmino:
    First implementation.