pypsa-eur/scripts/build_cop_profiles/DecentralHeatingCopApproximator.py

88 lines
2.9 KiB
Python

# -*- coding: utf-8 -*-
# SPDX-FileCopyrightText: : 2020-2024 The PyPSA-Eur Authors
#
# SPDX-License-Identifier: MIT
from typing import Union
import numpy as np
import xarray as xr
from BaseCopApproximator import BaseCopApproximator
class DecentralHeatingCopApproximator(BaseCopApproximator):
"""
Approximate the coefficient of performance (COP) for a heat pump in a
decentral heating system (individual/household heating).
Uses a quadratic regression on the temperature difference between the source and sink based on empirical data proposed by Staffell et al. 2012 .
References
----------
[1] Staffell et al., Energy & Environmental Science 11 (2012): A review of domestic heat pumps, https://doi.org/10.1039/C2EE22653G.
"""
def __init__(
self,
forward_temperature_celsius: Union[xr.DataArray, np.array],
source_inlet_temperature_celsius: Union[xr.DataArray, np.array],
source_type: str,
):
"""
Initialize the COPProfileBuilder object.
Parameters:
----------
forward_temperature_celsius : Union[xr.DataArray, np.array]
The forward temperature in Celsius.
return_temperature_celsius : Union[xr.DataArray, np.array]
The return temperature in Celsius.
source: str
The source of the heat pump. Must be either 'air' or 'ground'
"""
self.delta_t = forward_temperature_celsius - source_inlet_temperature_celsius
if source_type not in ["air", "ground"]:
raise ValueError("'source' must be one of ['air', 'ground']")
else:
self.source_type = source_type
def approximate_cop(self) -> Union[xr.DataArray, np.array]:
"""
Compute output of quadratic regression for air-/ground-source heat
pumps.
Calls the appropriate method depending on `source`.
"""
if self.source_type == "air":
return self._approximate_cop_air_source()
elif self.source_type == "ground":
return self._approximate_cop_ground_source()
def _approximate_cop_air_source(self) -> Union[xr.DataArray, np.array]:
"""
Evaluate quadratic regression for an air-sourced heat pump.
COP = 6.81 - 0.121 * delta_T + 0.000630 * delta_T^2
Returns
-------
Union[xr.DataArray, np.array]
The calculated COP values.
"""
return 6.81 - 0.121 * self.delta_t + 0.000630 * self.delta_t**2
def _approximate_cop_ground_source(self) -> Union[xr.DataArray, np.array]:
"""
Evaluate quadratic regression for a ground-sourced heat pump.
COP = 8.77 - 0.150 * delta_T + 0.000734 * delta_T^2
Returns
-------
Union[xr.DataArray, np.array]
The calculated COP values.
"""
return 8.77 - 0.150 * self.delta_t + 0.000734 * self.delta_t**2