BuildingSystems.Fluid.Geothermal.Borefields.BaseClasses.HeatTransfer.ThermalResponseFactors.infiniteLineSource

# .BuildingSystems.Fluid.Geothermal.Borefields.BaseClasses.HeatTransfer.ThermalResponseFactors.infiniteLineSource

Infinite line source model for borehole heat exchangers

## Information

This function evaluates the infinite line source solution. This solution gives the relation between the constant heat transfer rate (per unit length) injected by a line heat source of infinite length and the temperature raise in the medium. The infinite line source solution is defined by

where ΔT(t,r) is the temperature raise after a time t of constant heat injection and at a distance r from the line source, Q' is the heat injection rate per unit length, ks is the soil thermal conductivity and hILS is the infinite line source solution.

The infinite line source solution is given by the exponential integral

where αs is the ground thermal diffusivity. The exponential integral is implemented in BuildingSystems.Utilities.Math.Functions.exponentialIntegralE1.

#### Interface

>     function infiniteLineSource
>       extends Modelica.Icons.Function;
>       input Real t "Time";
>       input Real aSoi "Ground thermal diffusivity";
>       input Real dis "Radial distance between borehole axes";
>       output Real h_ils "Thermal response factor of borehole 1 on borehole 2";
>     end infiniteLineSource;

## Revisions

- March 22, 2018 by Massimo Cimmino:
  First implementation.

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