ProcessLib::HeatTransportBHE::BHE::BHE_1P Class Reference

Detailed Description

The BHE_1P class is the realization of single-pipe type of Borehole Heate Exchanger. In this class, the pipe heat capacity, pipe heat conductiion, pie 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:

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

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_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
double	updateFlowRateAndTemperature (double T_out, double current_time)
	Return the inflow temperature for the boundary condition.
double	thermalResistance (int const unknown_index) const
std::array< double, number_of_unknowns >	crossSectionAreas () const
void	updateHeatTransferCoefficients (double const flow_rate)
Public Member Functions inherited from ProcessLib::HeatTransportBHE::BHE::BHECommon
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 std::pair< int, int >	inflow_outflow_bc_component_ids []

Protected Attributes
PipeConfiguration1PType const	_pipe
double	_flow_velocity = std::numeric_limits<double>::quiet_NaN()
	Flow velocity inside the pipes. Depends on the flow_rate.

Private Member Functions
std::array< double, number_of_unknowns >	calcThermalResistances (double const Nu)

Static Private Member Functions
static double	compute_R_gs (double const chi, double const R_g)

Private Attributes
std::array< double, number_of_unknowns >	_thermal_resistances

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 25 of file BHE_1P.cpp.

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

References _thermal_resistances, ProcessLib::HeatTransportBHE::BHE::BHECommon::flowAndTemperatureControl, ProcessLib::HeatTransportBHE::BHE::RefrigerantProperties::reference_temperature, ProcessLib::HeatTransportBHE::BHE::BHECommon::refrigerant, and updateHeatTransferCoefficients().

Member Function Documentation

assembleRMatrices()

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

static 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 64 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(
                    "Error!!! In the function BHE_1P::assembleRMatrices, "
                    "the index of bhe resistance term is out of range! ");
        }
    }

References OGS_FATAL.

calcThermalResistances()

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

private

Definition at line 112 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 R_con_a = std::log(_pipe.single_pipe.outsideDiameter() /
                                    _pipe.single_pipe.diameter) /
                           (2.0 * pi * lambda_p);
 
    // thermal resistances of the grout
    double const D = borehole_geometry.diameter;
    double const pipe_outside_diameter = _pipe.single_pipe.outsideDiameter();
 
    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 = compute_R_gs(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, compute_R_gs(), ProcessLib::HeatTransportBHE::BHE::BoreholeGeometry::diameter, ProcessLib::HeatTransportBHE::BHE::Pipe::diameter, ProcessLib::HeatTransportBHE::BHE::BHECommon::grout, ProcessLib::HeatTransportBHE::BHE::GroutParameters::lambda_g, ProcessLib::HeatTransportBHE::BHE::Pipe::outsideDiameter(), ProcessLib::HeatTransportBHE::BHE::BHECommon::refrigerant, ProcessLib::HeatTransportBHE::BHE::PipeConfiguration1PType::single_pipe, ProcessLib::HeatTransportBHE::BHE::RefrigerantProperties::thermal_conductivity, and ProcessLib::HeatTransportBHE::BHE::Pipe::wall_thermal_conductivity.

Referenced by updateHeatTransferCoefficients().

compute_R_gs()

double ProcessLib::HeatTransportBHE::BHE::BHE_1P::compute_R_gs ( double const chi, double const R_g )

staticprivate

Definition at line 95 of file BHE_1P.cpp.

{
    return (1 - chi) * R_g;
}

Referenced by calcThermalResistances().

crossSectionAreas()

std::array< double, BHE_1P::number_of_unknowns > ProcessLib::HeatTransportBHE::BHE::BHE_1P::crossSectionAreas

(

)

const

Definition at line 171 of file BHE_1P.cpp.

{
    return {{_pipe.single_pipe.area(),
             borehole_geometry.area() - _pipe.single_pipe.outsideArea()}};
}

References _pipe, ProcessLib::HeatTransportBHE::BHE::BoreholeGeometry::area(), ProcessLib::HeatTransportBHE::BHE::Pipe::area(), ProcessLib::HeatTransportBHE::BHE::BHECommon::borehole_geometry, ProcessLib::HeatTransportBHE::BHE::Pipe::outsideArea(), and ProcessLib::HeatTransportBHE::BHE::PipeConfiguration1PType::single_pipe.

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 152 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 83 of file BHE_1P.cpp.

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

References _flow_velocity, ProcessLib::HeatTransportBHE::BHE::RefrigerantProperties::density, ProcessLib::HeatTransportBHE::BHE::BHECommon::refrigerant, and ProcessLib::HeatTransportBHE::BHE::RefrigerantProperties::specific_heat_capacity.

pipeHeatCapacities()

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

(

)

const

Definition at line 47 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::RefrigerantProperties::density, ProcessLib::HeatTransportBHE::BHE::BHECommon::grout, ProcessLib::HeatTransportBHE::BHE::GroutParameters::heat_cap_g, ProcessLib::HeatTransportBHE::BHE::GroutParameters::porosity_g, ProcessLib::HeatTransportBHE::BHE::BHECommon::refrigerant, ProcessLib::HeatTransportBHE::BHE::GroutParameters::rho_g, and ProcessLib::HeatTransportBHE::BHE::RefrigerantProperties::specific_heat_capacity.

pipeHeatConductions()

std::array< double, BHE_1P::number_of_unknowns > ProcessLib::HeatTransportBHE::BHE::BHE_1P::pipeHeatConductions

(

)

const

Definition at line 62 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;
 
    // 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 * _flow_velocity),
        // grout, Eq. 21
        (1.0 - porosity_g) * lambda_g,
    }};
}

References _flow_velocity, _pipe, ProcessLib::HeatTransportBHE::BHE::RefrigerantProperties::density, ProcessLib::HeatTransportBHE::BHE::BHECommon::grout, ProcessLib::HeatTransportBHE::BHE::GroutParameters::lambda_g, ProcessLib::HeatTransportBHE::BHE::PipeConfiguration1PType::longitudinal_dispersion_length, ProcessLib::HeatTransportBHE::BHE::GroutParameters::porosity_g, ProcessLib::HeatTransportBHE::BHE::BHECommon::refrigerant, ProcessLib::HeatTransportBHE::BHE::RefrigerantProperties::specific_heat_capacity, and ProcessLib::HeatTransportBHE::BHE::RefrigerantProperties::thermal_conductivity.

thermalResistance()

double ProcessLib::HeatTransportBHE::BHE::BHE_1P::thermalResistance ( int const unknown_index ) const

inline

Definition at line 106 of file BHE_1P.h.

    {
        return _thermal_resistances[unknown_index];
    }

References _thermal_resistances.

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 177 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 100 of file BHE_1P.cpp.

{
    auto const tm_flow_properties = calculateThermoMechanicalFlowPropertiesPipe(
        _pipe.single_pipe, borehole_geometry.length, refrigerant, flow_rate);
 
    _flow_velocity = tm_flow_properties.velocity;
    _thermal_resistances =
        calcThermalResistances(tm_flow_properties.nusselt_number);
}

References _flow_velocity, _pipe, _thermal_resistances, ProcessLib::HeatTransportBHE::BHE::BHECommon::borehole_geometry, calcThermalResistances(), ProcessLib::HeatTransportBHE::BHE::calculateThermoMechanicalFlowPropertiesPipe(), ProcessLib::HeatTransportBHE::BHE::BoreholeGeometry::length, ProcessLib::HeatTransportBHE::BHE::BHECommon::refrigerant, and ProcessLib::HeatTransportBHE::BHE::PipeConfiguration1PType::single_pipe.

Referenced by BHE_1P(), and updateFlowRateAndTemperature().

Member Data Documentation

_flow_velocity

double ProcessLib::HeatTransportBHE::BHE::BHE_1P::_flow_velocity = std::numeric_limits<double>::quiet_NaN()

protected

Flow velocity inside the pipes. Depends on the flow_rate.

Definition at line 135 of file BHE_1P.h.

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

_pipe

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

protected

Definition at line 132 of file BHE_1P.h.

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

_thermal_resistances

std::array<double, number_of_unknowns> ProcessLib::HeatTransportBHE::BHE::BHE_1P::_thermal_resistances

private

PHI_fg, PHI_gs; Here we store the thermal resistances needed for computation of the heat exchange coefficients in the governing equations of BHE.

Definition at line 147 of file BHE_1P.h.

Referenced by BHE_1P(), thermalResistance(), and updateHeatTransferCoefficients().

inflow_outflow_bc_component_ids

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

staticconstexpr

Initial value:

= {
        {0, 1}}

Definition at line 111 of file BHE_1P.h.

                                                                           {
        {0, 1}};

number_of_grout_zones

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

staticconstexpr

Definition at line 50 of file BHE_1P.h.

number_of_unknowns

constexpr 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:

• ProcessLib/HeatTransportBHE/BHE/BHE_1P.h
• ProcessLib/HeatTransportBHE/BHE/BHE_1P.cpp