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 39 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)
std::array< double, number_of_flow_legs >	flowLegs () const
std::array< double, number_of_unknowns >	pipeHeatCapacities () const
std::array< double, number_of_unknowns >	pipeHeatConductions () const
std::array< Eigen::Vector3d, number_of_unknowns >	pipeAdvectionVectors (Eigen::Vector3d const &elem_direction) const
std::vector< double >	thermalResistances (ParameterLib::SpatialPosition const &pos) const
double	updateFlowRateAndTemperature (double T_out, double current_time)
	Return the inflow temperature for the boundary condition.
std::array< double, number_of_unknowns >	crossSectionAreas (ParameterLib::SpatialPosition const &pos) 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

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 int	number_of_flow_legs = 1
static constexpr std::pair< int, int >	inflow_outflow_bc_component_ids []

Protected Attributes
PipeConfiguration1PType const	_pipe

Private Member Functions
std::vector< double >	calcThermalResistances (double const Nu, ParameterLib::SpatialPosition const &pos) const

Private Attributes
double	flow_velocity_ = 0.0
double	cached_nu_ = 0.0

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

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 21 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.

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 80 of file BHE_1P.h.

    {
        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,
		ParameterLib::SpatialPosition const &	pos ) const

private

Definition at line 107 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;
    // t=0.0: borehole properties are physically time-invariant (fixed at
    // drilling/installation); genuinely time-varying parameter types are
    // rejected in createPipe / createBoreholeGeometry.
    double const lambda_p =
        sampleStrictPositive(_pipe.single_pipe.wall_thermal_conductivity, 0.0,
                             pos, "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_outside_diameter = _pipe.single_pipe.outsideDiameter();
    double const R_con_a =
        pipeWallThermalResistance(_pipe.single_pipe, lambda_p);
 
    // thermal resistances of the grout
    double const D = sampleStrictPositive(borehole_geometry.diameter, 0.0, pos,
                                          "borehole_diameter");
    checkBoreholeVsPipeDiameter(D, pipe_outside_diameter, pos,
                                "BHE 1P grout resistance");
 
    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);
 
    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::checkBoreholeVsPipeDiameter(), ProcessLib::HeatTransportBHE::BHE::computeRgs(), ProcessLib::HeatTransportBHE::BHE::BHECommon::grout, ProcessLib::HeatTransportBHE::BHE::pipeWallThermalResistance(), ProcessLib::HeatTransportBHE::BHE::BHECommon::refrigerant, and ProcessLib::HeatTransportBHE::BHE::sampleStrictPositive().

Referenced by thermalResistances().

◆ crossSectionAreas()

std::array< double, BHE_1P::number_of_unknowns > ProcessLib::HeatTransportBHE::BHE::BHE_1P::crossSectionAreas ( ParameterLib::SpatialPosition const & pos ) const

Definition at line 171 of file BHE_1P.cpp.

{
    double const D = sampleStrictPositive(borehole_geometry.diameter, 0.0, pos,
                                          "borehole_diameter");
    double const borehole_area = Pipe::circleArea(D);
    return {{_pipe.single_pipe.area(),
             checkedGroutArea(borehole_area, _pipe.single_pipe.outsideArea(),
                              pos)}};
}

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

◆ flowLegs()

std::array< double, number_of_flow_legs > ProcessLib::HeatTransportBHE::BHE::BHE_1P::flowLegs ( ) const

inline

Signed fluid velocity per flow leg. Positive = flow along +elem_direction; negative = against it. BHE_1P has a single leg whose direction follows the line element's elem_direction.

Definition at line 56 of file BHE_1P.h.

    {
        return {+flow_velocity_};
    }

References flow_velocity_.

◆ 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 163 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 153 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 ) const

Definition at line 78 of file BHE_1P.cpp.

{
    double const& rho_r = refrigerant.density;
    double const& Cp_r = refrigerant.specific_heat_capacity;
 
    double const velocity = flow_velocity_;
    Eigen::Vector3d adv_vector = rho_r * Cp_r * velocity * elem_direction;
 
    return {// pipe
            adv_vector,
            // grout
            {0, 0, 0}};
}

References flow_velocity_, 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 42 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 ( ) const

Definition at line 57 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(flow_velocity_);
 
    return {{
        // pipe
        (lambda_r + rho_r * Cp_r * alpha_L * velocity_norm),
        // grout
        (1.0 - porosity_g) * lambda_g,
    }};
}

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

◆ thermalResistances()

std::vector< double > ProcessLib::HeatTransportBHE::BHE::BHE_1P::thermalResistances ( ParameterLib::SpatialPosition const & pos ) const

Return the full vector of thermal resistances for the element at pos, computed once using the cached Nusselt number. Intended to be called once per element by the assembler so that the resistance computation is not repeated per unknown and per integration point.

Definition at line 101 of file BHE_1P.cpp.

{
    return calcThermalResistances(cached_nu_, pos);
}

References cached_nu_, and calcThermalResistances().

◆ 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 182 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 92 of file BHE_1P.cpp.

{
    auto const tm_flow = calculateThermoMechanicalFlowPropertiesPipe(
        _pipe.single_pipe, borehole_geometry.length, refrigerant, flow_rate);
 
    flow_velocity_ = tm_flow.velocity;
    cached_nu_ = tm_flow.nusselt_number;
}

References _pipe, ProcessLib::HeatTransportBHE::BHE::BHECommon::borehole_geometry, cached_nu_, ProcessLib::HeatTransportBHE::BHE::calculateThermoMechanicalFlowPropertiesPipe(), flow_velocity_, and ProcessLib::HeatTransportBHE::BHE::BHECommon::refrigerant.

Referenced by BHE_1P(), and updateFlowRateAndTemperature().

Member Data Documentation

◆ _pipe

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

protected

Definition at line 142 of file BHE_1P.h.

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

◆ cached_nu_

double ProcessLib::HeatTransportBHE::BHE::BHE_1P::cached_nu_ = 0.0

private

Definition at line 151 of file BHE_1P.h.

Referenced by thermalResistances(), and updateHeatTransferCoefficients().

◆ flow_velocity_

double ProcessLib::HeatTransportBHE::BHE::BHE_1P::flow_velocity_ = 0.0

private

Scalar fluid velocity in the single pipe, refreshed in updateHeatTransferCoefficients. Sign mirrors the leg-0 (forward elem_direction) velocity; the per-leg signed velocity is derived from it in BHE_1P::flowLegs.

Definition at line 149 of file BHE_1P.h.

Referenced by flowLegs(), pipeAdvectionVectors(), pipeHeatConductions(), and updateHeatTransferCoefficients().

◆ 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 120 of file BHE_1P.h.

120 {

121 {0, 1}};

◆ number_of_flow_legs

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

staticconstexpr

Definition at line 51 of file BHE_1P.h.

◆ number_of_grout_zones

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

staticconstexpr

Definition at line 50 of file BHE_1P.h.

◆ number_of_unknowns

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

staticconstexpr

Definition at line 49 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

Private Attributes

Additional Inherited Members

Constructor & Destructor Documentation

◆ BHE_1P()

Member Function Documentation

◆ assembleRMatrices()

◆ calcThermalResistances()

◆ crossSectionAreas()

◆ flowLegs()

◆ getBHEBottomDirichletBCNodesAndComponents()

◆ getBHEInflowDirichletBCNodesAndComponents()

◆ pipeAdvectionVectors()

◆ pipeHeatCapacities()

◆ pipeHeatConductions()

◆ thermalResistances()

◆ updateFlowRateAndTemperature()

◆ updateHeatTransferCoefficients()

Member Data Documentation

◆ _pipe

◆ cached_nu_

◆ flow_velocity_

◆ inflow_outflow_bc_component_ids

◆ number_of_flow_legs

◆ number_of_grout_zones

◆ number_of_unknowns