Detailed Description

The BHE_1P class is the realization of single-pipe type of Borehole Heat Exchanger. In this class, the pipe heat capacity, pipe heat conduction, pipe advection vectors are initialized according to the geometry of the single-pipe type of BHE. For this type of BHE, 2 primary unknowns are assigned on the 1D BHE elements. They are the temperature in the pipe T_p, and temperature of the grout zone surrounding the single pipe T_g. These two primary variables are solved according to heat convection and conduction equations on the pipes and also in the grout zones. The interaction of the 1P type of BHE and the surrounding soil is regulated through the thermal resistance values, which are calculated specifically during the initialization of the class.

Definition at line 34 of file BHE_1P.h.

#include <BHE_1P.h>

Inheritance diagram for ProcessLib::HeatTransportBHE::BHE::BHE_1P:

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Collaboration diagram for ProcessLib::HeatTransportBHE::BHE::BHE_1P:

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Public Member Functions
	BHE_1P (BoreholeGeometry const &borehole, RefrigerantProperties const &refrigerant, GroutParameters const &grout, FlowAndTemperatureControl const &flowAndTemperatureControl, PipeConfiguration1PType const &pipes, bool const use_python_bcs)
BHE_1P	withGeometry (BoreholeGeometry const &g) const
std::array< double, number_of_unknowns >	pipeHeatCapacities () const
std::array< double, number_of_unknowns >	pipeHeatConductions (int const section_index=0) const
std::array< Eigen::Vector3d, number_of_unknowns >	pipeAdvectionVectors (Eigen::Vector3d const &elem_direction, int const section_index=0) const
double	updateFlowRateAndTemperature (double T_out, double current_time)
	Return the inflow temperature for the boundary condition.
std::array< double, number_of_unknowns >	crossSectionAreas (int const section_index=0) const
void	updateHeatTransferCoefficients (double const flow_rate)
Public Member Functions inherited from ProcessLib::HeatTransportBHE::BHE::BHECommon
	BHECommon (BoreholeGeometry const &borehole_geometry_, RefrigerantProperties const &refrigerant_, GroutParameters const &grout_, FlowAndTemperatureControl const &flowAndTemperatureControl_, bool const use_python_bcs_)
constexpr bool	isPowerBC () const
int	getNumberOfSections () const
	Get number of sections in the borehole geometry.
std::vector< double > const &	getSectionBoundaries () const
	Get section boundaries (cumulative distance from wellhead).
double	thermalResistanceAtSection (int const unknown_index, int const section_index) const
	Get thermal resistance for a specific section and unknown.

Static Public Member Functions
template<int NPoints, typename SingleUnknownMatrixType, typename RMatrixType, typename RPiSMatrixType, typename RSMatrixType>
static void	assembleRMatrices (int const idx_bhe_unknowns, Eigen::MatrixBase< SingleUnknownMatrixType > const &matBHE_loc_R, Eigen::MatrixBase< RMatrixType > &R_matrix, Eigen::MatrixBase< RPiSMatrixType > &R_pi_s_matrix, Eigen::MatrixBase< RSMatrixType > &R_s_matrix)
static std::array< std::pair< std::size_t, int >, 2 >	getBHEInflowDirichletBCNodesAndComponents (std::size_t const top_node_id, std::size_t const bottom_node_id, int const in_component_id)
static std::optional< std::array< std::pair< std::size_t, int >, 2 > >	getBHEBottomDirichletBCNodesAndComponents (std::size_t const, int const, int const)

Static Public Attributes
static constexpr int	number_of_unknowns = 2
static constexpr int	number_of_grout_zones = 1
static constexpr std::pair< int, int >	inflow_outflow_bc_component_ids []

Protected Attributes
PipeConfiguration1PType const	_pipe
Protected Attributes inherited from ProcessLib::HeatTransportBHE::BHE::BHECommon
std::vector< double >	_flow_velocities
std::vector< std::vector< double > >	_sectional_thermal_resistances

Private Member Functions
std::vector< double >	calcThermalResistances (double const Nu, int const section_index=0) const

Additional Inherited Members
Public Attributes inherited from ProcessLib::HeatTransportBHE::BHE::BHECommon
BoreholeGeometry const	borehole_geometry
RefrigerantProperties const	refrigerant
GroutParameters const	grout
FlowAndTemperatureControl const	flowAndTemperatureControl
bool const	use_python_bcs
Protected Member Functions inherited from ProcessLib::HeatTransportBHE::BHE::BHECommon
template<typename Fn>
void	recomputeSectionalResistances (Fn &&calcForSection)
	Recompute _sectional_thermal_resistances for all sections.
double	getClampedFlowVelocity (int const section_index) const
	Get velocity for a section, clamping to last section if index exceeds the number of velocity entries. Returns 0 when empty.
std::vector< double > const &	getThermalResistancesAtSection (int const section_index) const
	Get the thermal resistance vector for a given section.

Constructor & Destructor Documentation

◆ BHE_1P()

ProcessLib::HeatTransportBHE::BHE::BHE_1P::BHE_1P	(	BoreholeGeometry const &	borehole,
		RefrigerantProperties const &	refrigerant,
		GroutParameters const &	grout,
		FlowAndTemperatureControl const &	flowAndTemperatureControl,
		PipeConfiguration1PType const &	pipes,
		bool const	use_python_bcs )

Definition at line 19 of file BHE_1P.cpp.

    : BHECommon{borehole, refrigerant, grout, flowAndTemperatureControl,
                use_python_bcs},
      _pipe(pipes)
{
    // Initialize thermal resistances.
    auto values = visit(
        [&](auto const& control)
        {
            return control(refrigerant.reference_temperature,
                           0. /* initial time */);
        },
        flowAndTemperatureControl);
    updateHeatTransferCoefficients(values.flow_rate);
}

References ProcessLib::HeatTransportBHE::BHE::BHECommon::BHECommon(), _pipe, ProcessLib::HeatTransportBHE::BHE::BHECommon::flowAndTemperatureControl, ProcessLib::HeatTransportBHE::BHE::BHECommon::grout, ProcessLib::HeatTransportBHE::BHE::BHECommon::refrigerant, updateHeatTransferCoefficients(), and ProcessLib::HeatTransportBHE::BHE::BHECommon::use_python_bcs.

Referenced by withGeometry().

Member Function Documentation

◆ assembleRMatrices()

template<int NPoints, typename SingleUnknownMatrixType, typename RMatrixType, typename RPiSMatrixType, typename RSMatrixType>

void ProcessLib::HeatTransportBHE::BHE::BHE_1P::assembleRMatrices	(	int const	idx_bhe_unknowns,
		Eigen::MatrixBase< SingleUnknownMatrixType > const &	matBHE_loc_R,
		Eigen::MatrixBase< RMatrixType > &	R_matrix,
		Eigen::MatrixBase< RPiSMatrixType > &	R_pi_s_matrix,
		Eigen::MatrixBase< RSMatrixType > &	R_s_matrix )

inlinestatic

Definition at line 69 of file BHE_1P.h.

    {
        // Here we are looping over two resistance terms
        // First PHI_fg is the resistance between pipe and grout
        // Second PHI_gs is the resistance between grout and soil
        switch (idx_bhe_unknowns)
        {
            case 0:  // PHI_fg
                R_matrix.block(0, NPoints, NPoints, NPoints) +=
                    -1.0 * matBHE_loc_R;
                R_matrix.block(NPoints, 0, NPoints, NPoints) +=
                    -1.0 * matBHE_loc_R;
 
                R_matrix.block(0, 0, NPoints, NPoints) +=
                    matBHE_loc_R;  // K_i/o
                R_matrix.block(NPoints, NPoints, NPoints, NPoints) +=
                    matBHE_loc_R;  // K_fg
                return;
            case 1:  // PHI_gs
                R_s_matrix += matBHE_loc_R;
 
                R_pi_s_matrix.block(NPoints, 0, NPoints, NPoints) +=
                    -1.0 * matBHE_loc_R;
 
                R_matrix.block(NPoints, NPoints, NPoints, NPoints) +=
                    matBHE_loc_R;  // K_fg
                return;
            default:
                OGS_FATAL(
                    "BHE_1P::assembleRMatrices: unknown index {:d} "
                    "out of range.",
                    idx_bhe_unknowns);
        }
    }

References OGS_FATAL.

◆ calcThermalResistances()

std::vector< double > ProcessLib::HeatTransportBHE::BHE::BHE_1P::calcThermalResistances	(	double const	Nu,
		int const	section_index = 0 ) const

private

Definition at line 109 of file BHE_1P.cpp.

{
    constexpr double pi = std::numbers::pi;
 
    double const lambda_r = refrigerant.thermal_conductivity;
    double const lambda_g = grout.lambda_g;
    double const lambda_p = _pipe.single_pipe.wall_thermal_conductivity;
 
    // thermal resistances due to advective flow of refrigerant in the pipe
    double const R_adv_i1 = 1.0 / (Nu * lambda_r * pi);
 
    // thermal resistance due to thermal conductivity of the pipe wall material
    double const pipe_diameter = _pipe.single_pipe.diameter;
    double const pipe_outside_diameter = _pipe.single_pipe.outsideDiameter();
    double const R_con_a =
        std::log(pipe_outside_diameter / pipe_diameter) / (2.0 * pi * lambda_p);
 
    // thermal resistances of the grout
    double const D =
        borehole_geometry.sections.diameterAtSection(section_index);
 
    double const chi = std::log(std::sqrt(D * D + pipe_outside_diameter *
                                                      pipe_outside_diameter) /
                                std::sqrt(2) / pipe_outside_diameter) /
                       std::log(D / pipe_outside_diameter);
    double const R_g =
        std::log(D / pipe_outside_diameter) / 2 / (pi * lambda_g);
 
    double const R_con_b = chi * R_g;
 
    // thermal resistances due to grout-soil exchange
    double const R_gs = computeRgs(chi, R_g);
 
    // Eq. 29 and 30
    double const R_fg = R_adv_i1 + R_con_a + R_con_b;
 
    return {R_fg, R_gs};
}

References _pipe, ProcessLib::HeatTransportBHE::BHE::BHECommon::borehole_geometry, ProcessLib::HeatTransportBHE::BHE::computeRgs(), ProcessLib::HeatTransportBHE::BHE::BHECommon::grout, and ProcessLib::HeatTransportBHE::BHE::BHECommon::refrigerant.

Referenced by updateHeatTransferCoefficients().

◆ crossSectionAreas()

std::array< double, BHE_1P::number_of_unknowns > ProcessLib::HeatTransportBHE::BHE::BHE_1P::crossSectionAreas ( int const section_index = 0 ) const

Definition at line 169 of file BHE_1P.cpp.

{
    return {{_pipe.single_pipe.area(),
             checkedGroutArea(
                 borehole_geometry.sections.areaAtSection(section_index),
                 _pipe.single_pipe.outsideArea(), section_index)}};
}

References _pipe, ProcessLib::HeatTransportBHE::BHE::BHECommon::borehole_geometry, and ProcessLib::HeatTransportBHE::BHE::checkedGroutArea().

◆ getBHEBottomDirichletBCNodesAndComponents()

std::optional< std::array< std::pair< std::size_t, int >, 2 > > ProcessLib::HeatTransportBHE::BHE::BHE_1P::getBHEBottomDirichletBCNodesAndComponents	(	std::size_t const	,
		int const	,
		int const	)

static

Definition at line 161 of file BHE_1P.cpp.

{
    return {};
}

◆ getBHEInflowDirichletBCNodesAndComponents()

std::array< std::pair< std::size_t, int >, 2 > ProcessLib::HeatTransportBHE::BHE::BHE_1P::getBHEInflowDirichletBCNodesAndComponents	(	std::size_t const	top_node_id,
		std::size_t const	bottom_node_id,
		int const	in_component_id )

static

Definition at line 150 of file BHE_1P.cpp.

{
    return {std::make_pair(top_node_id, in_component_id),
            std::make_pair(bottom_node_id, in_component_id)};
}

◆ pipeAdvectionVectors()

std::array< Eigen::Vector3d, BHE_1P::number_of_unknowns > ProcessLib::HeatTransportBHE::BHE::BHE_1P::pipeAdvectionVectors	(	Eigen::Vector3d const &	elem_direction,
		int const	section_index = 0 ) const

Definition at line 79 of file BHE_1P.cpp.

{
    double const& rho_r = refrigerant.density;
    double const& Cp_r = refrigerant.specific_heat_capacity;
 
    double const velocity = getClampedFlowVelocity(section_index);
    Eigen::Vector3d adv_vector = rho_r * Cp_r * velocity * elem_direction;
 
    return {// pipe, Eq. 19
            adv_vector,
            // grout, Eq. 21
            {0, 0, 0}};
}

References ProcessLib::HeatTransportBHE::BHE::BHECommon::getClampedFlowVelocity(), and ProcessLib::HeatTransportBHE::BHE::BHECommon::refrigerant.

◆ pipeHeatCapacities()

std::array< double, BHE_1P::number_of_unknowns > ProcessLib::HeatTransportBHE::BHE::BHE_1P::pipeHeatCapacities ( ) const

Definition at line 40 of file BHE_1P.cpp.

{
    double const rho_r = refrigerant.density;
    double const specific_heat_capacity = refrigerant.specific_heat_capacity;
    double const rho_g = grout.rho_g;
    double const porosity_g = grout.porosity_g;
    double const heat_cap_g = grout.heat_cap_g;
 
    return {{
        /*pipe*/ rho_r * specific_heat_capacity,
        /*grout*/ (1.0 - porosity_g) * rho_g * heat_cap_g,
    }};
}

References ProcessLib::HeatTransportBHE::BHE::BHECommon::grout, and ProcessLib::HeatTransportBHE::BHE::BHECommon::refrigerant.

◆ pipeHeatConductions()

std::array< double, BHE_1P::number_of_unknowns > ProcessLib::HeatTransportBHE::BHE::BHE_1P::pipeHeatConductions ( int const section_index = 0 ) const

Definition at line 55 of file BHE_1P.cpp.

{
    double const lambda_r = refrigerant.thermal_conductivity;
    double const rho_r = refrigerant.density;
    double const Cp_r = refrigerant.specific_heat_capacity;
    double const alpha_L = _pipe.longitudinal_dispersion_length;
    double const porosity_g = grout.porosity_g;
    double const lambda_g = grout.lambda_g;
 
    double const velocity_norm =
        std::abs(getClampedFlowVelocity(section_index));
 
    // Here we calculate the laplace coefficients in the governing
    // equations of the BHE.
    return {{
        // pipe, Eq. 19
        (lambda_r + rho_r * Cp_r * alpha_L * velocity_norm),
        // grout, Eq. 21
        (1.0 - porosity_g) * lambda_g,
    }};
}

References _pipe, ProcessLib::HeatTransportBHE::BHE::BHECommon::getClampedFlowVelocity(), ProcessLib::HeatTransportBHE::BHE::BHECommon::grout, and ProcessLib::HeatTransportBHE::BHE::BHECommon::refrigerant.

◆ updateFlowRateAndTemperature()

double ProcessLib::HeatTransportBHE::BHE::BHE_1P::updateFlowRateAndTemperature	(	double	T_out,
		double	current_time )

Return the inflow temperature for the boundary condition.

Definition at line 178 of file BHE_1P.cpp.

{
    auto values =
        visit([&](auto const& control) { return control(T_out, current_time); },
              flowAndTemperatureControl);
    updateHeatTransferCoefficients(values.flow_rate);
    return values.temperature;
}

References ProcessLib::HeatTransportBHE::BHE::BHECommon::flowAndTemperatureControl, and updateHeatTransferCoefficients().

◆ updateHeatTransferCoefficients()

void ProcessLib::HeatTransportBHE::BHE::BHE_1P::updateHeatTransferCoefficients ( double const flow_rate )

Definition at line 94 of file BHE_1P.cpp.

{
    auto const tm_flow = calculateThermoMechanicalFlowPropertiesPipe(
        _pipe.single_pipe, borehole_geometry.length, refrigerant, flow_rate);
 
    _flow_velocities = {tm_flow.velocity};
 
    recomputeSectionalResistances(
        [&](int i)
        { return calcThermalResistances(tm_flow.nusselt_number, i); });
}

References ProcessLib::HeatTransportBHE::BHE::BHECommon::_flow_velocities, _pipe, ProcessLib::HeatTransportBHE::BHE::BHECommon::borehole_geometry, calcThermalResistances(), ProcessLib::HeatTransportBHE::BHE::calculateThermoMechanicalFlowPropertiesPipe(), ProcessLib::HeatTransportBHE::BHE::BHECommon::recomputeSectionalResistances(), and ProcessLib::HeatTransportBHE::BHE::BHECommon::refrigerant.

Referenced by BHE_1P(), and updateFlowRateAndTemperature().

◆ withGeometry()

BHE_1P ProcessLib::HeatTransportBHE::BHE::BHE_1P::withGeometry ( BoreholeGeometry const & g ) const

inline

Construct a copy with different borehole geometry. Used for grouped BHE definitions.

Definition at line 46 of file BHE_1P.h.

    {
        return {g,     refrigerant,   grout, flowAndTemperatureControl,
                _pipe, use_python_bcs};
    }

References BHE_1P(), _pipe, ProcessLib::HeatTransportBHE::BHE::BHECommon::flowAndTemperatureControl, ProcessLib::HeatTransportBHE::BHE::BHECommon::grout, ProcessLib::HeatTransportBHE::BHE::BHECommon::refrigerant, and ProcessLib::HeatTransportBHE::BHE::BHECommon::use_python_bcs.

Member Data Documentation

◆ _pipe

PipeConfiguration1PType const ProcessLib::HeatTransportBHE::BHE::BHE_1P::_pipe

protected

Definition at line 134 of file BHE_1P.h.

Referenced by BHE_1P(), calcThermalResistances(), crossSectionAreas(), pipeHeatConductions(), updateHeatTransferCoefficients(), and withGeometry().

◆ inflow_outflow_bc_component_ids

std::pair<int, int> ProcessLib::HeatTransportBHE::BHE::BHE_1P::inflow_outflow_bc_component_ids[]

staticconstexpr

Initial value:

= {

{0, 1}}

Definition at line 112 of file BHE_1P.h.

112 {

113 {0, 1}};

◆ number_of_grout_zones

int ProcessLib::HeatTransportBHE::BHE::BHE_1P::number_of_grout_zones = 1

staticconstexpr

Definition at line 53 of file BHE_1P.h.

◆ number_of_unknowns

int ProcessLib::HeatTransportBHE::BHE::BHE_1P::number_of_unknowns = 2

staticconstexpr

Definition at line 52 of file BHE_1P.h.

The documentation for this class was generated from the following files:

Detailed Description

Public Member Functions

Static Public Member Functions

Static Public Attributes

Protected Attributes

Private Member Functions

Additional Inherited Members

Constructor & Destructor Documentation

◆ BHE_1P()

Member Function Documentation

◆ assembleRMatrices()

◆ calcThermalResistances()

◆ crossSectionAreas()

◆ getBHEBottomDirichletBCNodesAndComponents()

◆ getBHEInflowDirichletBCNodesAndComponents()

◆ pipeAdvectionVectors()

◆ pipeHeatCapacities()

◆ pipeHeatConductions()

◆ updateFlowRateAndTemperature()

◆ updateHeatTransferCoefficients()

◆ withGeometry()

Member Data Documentation

◆ _pipe

◆ inflow_outflow_bc_component_ids

◆ number_of_grout_zones

◆ number_of_unknowns