Ground data

The ground data classes you can use have either:

1. A constant ground temperature

2. A constant ground geothermal heat flux

3. A constant ground temperature gradient

All of these three classes are children of the abstract class _GroundData.

class GHEtool.VariableClasses.GroundData._GroundData.GroundLayer(k_s: Optional[float] = None, volumetric_heat_capacity: float = 2400000.0, thickness: Optional[float] = None)

Bases: BaseClass

Contains the information about a certain ground layer.

Parameters

k_sfloat

Layer thermal conductivity [W/mK]

volumetric_heat_capacityfloat

Layer volumetric heat capacity [J/m³K]

thicknessfloat

Layer thickness [m]. None is assumed infinite depth

non_negative(value) → float

This function returns the value if the value > 0. Otherwise, an error is raised.

Parameters

valuefloat

Value to be checked

Returns

float

Value

Raises

ValueError

When the value equals 0 or is smaller

class GHEtool.VariableClasses.GroundData._GroundData._GroundData(k_s: Optional[float] = None, volumetric_heat_capacity: float = 2400000.0)

Bases: BaseClass, ABC

Contains information regarding the ground data of the borefield.

Parameters

k_sfloat

Ground thermal conductivity [W/mK]

volumetric_heat_capacityfloat

The volumetric heat capacity of the ground [J/m3K]

add_layer_on_bottom(layer: Union[GroundLayer, List[GroundLayer]]) → None

This function adds a ground layer on the bottom of the array. This hence becomes the deepest ground layer.

Parameters

layerGroundLayer or list of ground layers

GroundLayer object with thermal properties of this layer

Returns

None

Raises

ValueError

When you add a ground layer on the bottom of a layer which has no predefined depth

add_layer_on_top(layer: Union[GroundLayer, List[GroundLayer]]) → None

This function adds a ground layer on the top of the array. This hence becomes the highest ground layer.

Parameters

layerGroundLayer or list of ground layers

GroundLayer object with thermal properties of this layer

Returns

None

Raises

ValueError

When you add a ground layer with no specified depth and there are already ground layers in the array

alpha(H: float = 100) → float

Returns the ground thermal diffusivity in m²/s for a given depth. If no volumetric heat capacity or conductivity is given, None is returned.

Parameters

Hfloat

Depth in meters.

Returns

float

Ground thermal diffusivity in m²/s for a given depth.

abstract calculate_Tg(H: float) → float

This function gives back the ground temperature

Parameters

Hfloat

Depth of the borefield [m]

Returns

Tgfloat

Ground temperature [deg C]

abstract calculate_delta_H(temperature_diff: float) → float

This function calculates the difference in depth for a given difference in temperature.

Parameters

temperature_difffloat

Difference in temperature [deg C]

Returns

Difference in depth [m]float

calculate_value(thickness_list: list, cumulative_thickness_list: list, y_range: list, H: float) → float

This function calculates the average value of a certain y_range of values for a certain depth, given the thickness of the ground layers.

Parameters

thickness_listlist

List of all the layer thicknesses

cumulative_thickness_listlist

Cumulative sum of all the layer thicknesses

y_rangelist

Range with the values for each layer

Hfloat

Depth [m]

Returns

float

Calculated value for either k_s or volumetric heat capacity

check_depth(H: float) → bool

Checks if the depth is correct. A depth is False when it is lower than 0 or it exceeds the deepest ground layer and last_layer_infinite is set to False.

Parameters

Hfloat

Depth [m]

Returns

bool

True if the depth is valid

Raises

ValueError

When a depth is requested that is either smaller than zero or larger than the maximum depth.

k_s(H: float = 100) → float

Returns the ground thermal conductivity in W/mK for a given depth.

Parameters

Hfloat

Depth in meters.

Returns

float

Ground thermal conductivity in W/mK for a given depth.

max_depth(max_temp: float) → float

This function returns the maximum depth, based on the maximum temperature. The maximum is the depth where the ground temperature equals the maximum temperature limit.

Parameters

max_tempfloat

Maximum temperature [deg C]

Returns

Depthfloat

Maximum depth [m]

volumetric_heat_capacity(H: float = 100) → float

Returns the ground volumetric heat capacity in J/m³K for a given depth.

Parameters

Hfloat

Depth in meters.

Returns

float

Ground volumetric heat capacity in J/m³K for a given depth.

class GHEtool.VariableClasses.GroundData.GroundConstantTemperature.GroundConstantTemperature(k_s: Optional[float] = None, T_g: Optional[float] = None, volumetric_heat_capacity: float = 2400000.0)

Bases: _GroundData

Parameters

k_sfloat

Ground thermal conductivity [W/mK]

T_gfloat

Ground temperature at infinity [deg C]

volumetric_heat_capacityfloat

The volumetric heat capacity of the ground [J/m3K]

calculate_Tg(H: Optional[float] = None) → float

This function gives back the ground temperature.

Parameters

Hfloat

Depth of the borefield [m] (not used)

Returns

Tgfloat

Ground temperature [deg C]

calculate_delta_H(temperature_diff: float) → float

This function calculates the difference in depth for a given difference in temperature.

Parameters

temperature_difffloat

Difference in temperature [deg C]

Returns

float

Difference in depth [m]

class GHEtool.VariableClasses.GroundData.GroundFluxTemperature.GroundFluxTemperature(k_s: Optional[float] = None, T_g: Optional[float] = None, volumetric_heat_capacity: float = 2400000.0, flux: float = 0.06)

Bases: _GroundData

Parameters

k_sfloat

Ground thermal conductivity [W/mK]

T_gfloat

Surface ground temperature [deg C]

volumetric_heat_capacityfloat

The volumetric heat capacity of the ground [J/m3K]

fluxfloat

The geothermal heat flux [W/m2]

calculate_Tg(H: float) → float

This function gives back the ground temperature at a depth H.

Parameters

Hfloat

Depth at which the temperature should be calculated [m]

Returns

Tgfloat

Ground temperature [deg C]

calculate_delta_H(temperature_diff: float, H: float = 100) → float

This function calculates the difference in depth for a given difference in temperature.

Parameters

temperature_difffloat

Difference in temperature [deg C]

Hfloat

Depth at which the average ground thermal conductivity should be taken [m]

Returns

float

Difference in depth [m]

class GHEtool.VariableClasses.GroundData.GroundTemperatureGradient.GroundTemperatureGradient(k_s: Optional[float] = None, T_g: Optional[float] = None, volumetric_heat_capacity: float = 2400000.0, gradient: float = 3.0)

Bases: _GroundData

Parameters

k_sfloat

Ground thermal conductivity [W/mK]

T_gfloat

Surface ground temperature [deg C]

volumetric_heat_capacityfloat

The volumetric heat capacity of the ground [J/m3K]

gradientfloat

The geothermal temperature gradient [K/100m]

calculate_Tg(H: float) → float

This function gives back the ground temperature at a depth H.

Parameters

Hfloat

Depth at which the temperature should be calculated [m]

Returns

Tgfloat

Ground temperature [deg C]

calculate_delta_H(temperature_diff: float) → float

This function calculates the difference in depth for a given difference in temperature.

Parameters

temperature_difffloat

Difference in temperature [deg C]

Returns

float

Difference in depth [m]