def test_raised_exception_05():
"""Test if an exception is raised if ... """
with pytest.raises(ValueError):
cmpr_hp_chllr.calc_cops(temp_high=[39],
temp_low=[17],
quality_grade=0.4,
mode='chiller',
temp_threshold_icing=2,
factor_icing=0.8)
def test_raised_exception_01():
"""Test if an exception is raised if temp_low is not a list."""
with pytest.raises(TypeError):
cmpr_hp_chllr.calc_cops(
temp_high=[40],
temp_low=12, # ERROR - temp_low has to be a list!
quality_grade=0.4,
mode='heat_pump',
temp_threshold_icing=2,
factor_icing=0.8)
def test_raised_exception_03():
"""Test if an exception is raised if temp_high and
temp_low have different length AND none of them is of length 1."""
with pytest.raises(IndexError):
cmpr_hp_chllr.calc_cops(
temp_high=[40, 39, 39],
temp_low=[12, 10], # ERROR - len(temp_low) has
# to be 1 or equal to len(temp_high)
quality_grade=0.4,
mode='heat_pump',
temp_threshold_icing=2,
factor_icing=0.8)
def test_cop_calculation_airsource_hp_with_icing_02():
cops_ASHP = cmpr_hp_chllr.calc_cops(temp_high=[40],
temp_low=[2.3],
quality_grade=0.5,
mode='heat_pump',
temp_threshold_icing=2,
factor_icing=0.8)
assert cops_ASHP == [4.15318302387268]
def test_calc_cops_with_Series_02():
set_temp_each_hour = {'01:00': 40, '02:00': 40, '03:00': 40}
temp_h_series = pd.Series(set_temp_each_hour)
cops_HP = cmpr_hp_chllr.calc_cops(temp_high=temp_h_series,
temp_low=[12],
quality_grade=0.4,
mode='heat_pump')
assert cops_HP == [4.473571428571428, 4.473571428571428, 4.473571428571428]
def test_calc_cops_with_Series_01():
ambient_temp_each_hour = {'01:00': 12, '02:00': 12, '03:00': 12}
temp_l_series = pd.Series(ambient_temp_each_hour)
cops_HP = cmpr_hp_chllr.calc_cops(temp_high=[40],
temp_low=temp_l_series,
quality_grade=0.4,
mode='heat_pump')
assert cops_HP == [4.473571428571428, 4.473571428571428, 4.473571428571428]
def test_cop_calculation_airsource_hp_with_icing_01():
cops_ASHP = cmpr_hp_chllr.calc_cops(temp_high=[40],
temp_low=[1.3],
quality_grade=0.5,
mode='heat_pump',
temp_threshold_icing=2,
factor_icing=0.8)
assert cops_ASHP == [3.236692506459949]
# Delta t
temp_difference = range(10, 71, 1)
temp_difference_industrial = range(20, 142, 2)
temperature_diff_q_grade = range(5, 147, 2)
# Quality grades
quality_grades = [q / 10 for q in range(2, 11, 2)]
cops = pd.DataFrame()
# COPs of ax exemplary heat pump for domestic hot water
# (sink temperature below 100 degC)
cops['temperature_difference'] = temp_difference
list_temp_low = [temp_high - temp_diff for temp_diff in temp_difference]
cops[temp_high] = cmpr_hp_chiller.calc_cops(temp_high=[temp_high],
temp_low=list_temp_low,
quality_grade=0.35,
mode='heat_pump')
# COPs of ax exemplary hight temperature heat pump for industrial applications
# (sink temperature above 100 degC and higher quality grade)
cops['temperature_difference_industrial'] = temp_difference_industrial
temp_l_ind = [
temp_high_industrial - temp_diff
for temp_diff in temp_difference_industrial
]
cops[temp_high_industrial] = cmpr_hp_chiller.calc_cops(
temp_high=[temp_high_industrial],
temp_low=temp_l_ind,
quality_grade=0.45,
mode='heat_pump')
def calculate_cops_and_eers(
weather,
lat,
lon,
mode,
temperature_col="temp_air",
user_inputs_pvcompare_directory=None,
user_inputs_mvs_directory=None,
):
r"""
Calculates the COPs of a heat pump or EERs of a chiller depending on `mode`.
Temperature dependency is taken into consideration.
For these calculations the ``calc_cops()` <functionality>`_ functionality of
`oemof.thermal <https://oemof-thermal.readthedocs.io/en/stable/>`_ is
used. Data like quality grade and factor icing is read from the file
`heat_pumps_and_chillers.csv` in the `input_directory`.
Negative values, which might occur due to high ambient temperatures in summer are
set to zero.
Parameters
----------
weather : :pandas:`pandas.DataFrame<frame>`
Contains weather data time series. Required: ambient temperature in
column `temperature_col`.
lat : float
Latitude of ambient temperature location in `weather`.
lon : float
Longitude of ambient temperature location in `weather`.
temperature_col : str
Name of column in `weather` containing ambient temperature.
Default: "temp_air".
mode : str
Defines whether COPs of heat pump ("heat_pump") or EERs of chiller
("chiller") are calculated. Default: "heat_pump".
user_inputs_pvcompare_directory: str or None
Path to user input directory. If None,
`constants.DEFAULT_USER_INPUTS_PVCOMPARE_DIRECTORY` is used.
Default: None.
user_inputs_mvs_directory: str or None
Path to input directory containing files that describe the energy
system and that are an input to MVS. If None,
`constants.DEFAULT_USER_INPUTS_MVS_DIRECTORY` is used.
Default: None.
Returns
-------
None
"""
# read parameters from file
if user_inputs_pvcompare_directory == None:
user_inputs_pvcompare_directory = (
constants.DEFAULT_USER_INPUTS_PVCOMPARE_DIRECTORY)
if user_inputs_mvs_directory == None:
user_inputs_mvs_directory = constants.DEFAULT_USER_INPUTS_MVS_DIRECTORY
filename = os.path.join(user_inputs_pvcompare_directory,
"heat_pumps_and_chillers.csv")
try:
parameters_complete = pd.read_csv(filename)
parameters = pd.read_csv(filename, header=0, index_col=0).loc[mode]
except KeyError:
raise ValueError(
f"Parameter `mode` should be 'heat_pump' or 'chiller' but is {mode}"
)
# prepare parameters for calc_cops
def process_temperatures(temperature, level, mode, technology):
r"""
Processes temperatures for specific `level`, `mode`, and `technology`.
`temperature` can be passed in the following way:
1. As NaN - The lower/higher temperature of the heat pump/chiller equals the ambient temperature time series
2. As single value (float or int) - The temperature is constant
3. As time series - The temperature is not constant or differs from ambient temperature (eg. ground source)
Parameters
----------
temperature : float, int, np.nan, :pandas:`pandas.Series<series>
Passed temperature which was written from input data.
level : str
Defines whether high or low temperature has been passed.
mode : str
Defines whether COPs of heat pump ("heat_pump") or EERs of chiller
("chiller") are calculated.
technology: str
Defines whether technology is a "brine-water", "air-air"
or "air-water".
Returns
-------
temperature: list
Temperature adjusted to use case of plant.
"""
if isinstance(temperature, float):
if pd.isna(temperature):
# In case of NaN
if (level == "low"
and mode == "heat_pump") or (level == "high"
and mode == "chiller"):
if technology == "brine-water":
# Prepare mean yearly ambient temperature for calc_cops (numeric)
temperature = np.average(
weather[temperature_col].values)
temperature = [temperature]
elif technology == "air-air" or technology == "air-water":
# Prepare ambient temperature for calc_cops (list)
temperature = weather[temperature_col].values.tolist()
logging.info(
f"The {mode} is modeled with the ambient temperature from weather data as {level} temperature."
)
else:
# Prepare ambient temperature for calc_cops (list)
temperature = weather[temperature_col].values.tolist()
logging.warning(
f"The technology of the {mode} should be either 'air-air', 'air-water' or 'brine-water'."
f"'{technology}' is not a valid technology. The {mode} is modeled as an air source {mode} by default"
f" and with the ambient temperature from weather data as {level} temperature."
)
return temperature
else:
# Required parameter is missing
raise ValueError(
f"Missing required value of {mode}: Please provide a numeric as {mode}'s {level} temperature in heat_pumps_and_chillers.csv."
)
elif isinstance(temperature, (float, int)):
# Numerics pass
temperature = [temperature]
logging.info(
f"The {mode} is modeled with the constant {level} temperature of {temperature} °C"
)
return temperature
elif isinstance(temperature, str):
# In case temperatures are provided as time series in separate file
try:
temp_string = temperature.split("'")
temp_filename = temp_string[3]
temp_header = temp_string[7]
temperature_df = pd.read_csv(
os.path.join(user_inputs_pvcompare_directory,
temp_filename))
temperature_df = temperature_df.set_index(temp_header)
temperature = temperature_df.index.tolist()
logging.info(
f"The {mode} is modeled with passed time series as {level} temperature."
)
return temperature
except AttributeError:
raise ValueError(
f"Wrong value: Please check the {level} temperature of the {mode}. See the documentation on passing the {mode}'s temperatures for further information"
)
else:
# Required parameter is missing in case of None or else
raise ValueError(
f"Missing required value of {mode}: Please provide a numeric as {mode}'s {level} temperature in heat_pumps_and_chillers.csv."
)
low_temperature = process_temperatures(parameters.temp_low, "low", mode,
parameters.technology)
high_temperature = process_temperatures(parameters.temp_high, "high", mode,
parameters.technology)
if pd.isna(parameters.quality_grade):
if parameters.technology == "air-air":
if mode == "heat_pump":
quality_grade = 0.1852
elif mode == "chiller":
quality_grade = 0.3
elif parameters.technology == "air-water":
if mode == "heat_pump":
quality_grade = 0.403
elif mode == "chiller":
# Required parameter is missing in case of None or else
raise ValueError(
f"Missing required value of {mode}: There is no default value of a quality grade provided for an {parameters.technology} {mode}"
f"Please provide a valid value of the quality grade.")
elif parameters.technology == "brine-water":
if mode == "heat_pump":
quality_grade = 0.53
elif mode == "chiller":
# Required parameter is missing in case of None or else
raise ValueError(
f"Missing required value of {mode}: There is no default value of a quality grade provided for a {parameters.technology} {mode}. "
f"Please provide a valid value of the quality grade.")
else:
# Required parameter is missing in case of different technology
raise ValueError(
f"Missing required value of {mode}: '{parameters.quality_grade}' could not be processed as quality grade. "
f"Please provide a valid value or the technology of the {mode} in order to model with default quality grade."
)
elif isinstance(parameters.quality_grade, (float, int)):
quality_grade = float(parameters.quality_grade)
else:
# Required parameter is missing in case of None or else
raise ValueError(
f"Missing required value of {mode}: '{parameters.quality_grade}' could not be processed as quality grade."
f"Please provide a valid value or the technology of the {mode} in order to model from default quality grade."
)
# Save default quality grade to heat_pumps_and_chillers.csv
parameters_complete.quality_grade = quality_grade
parameters_complete.to_csv(filename,
index=False,
header=True,
float_format="%g")
# create add on to filename (year, lat, lon)
year = maya.parse(weather.index[int(len(weather) / 2)]).datetime().year
# calculate COPs or EERs with oemof thermal
if mode == "heat_pump":
if len(high_temperature) > 1:
add_on = f"_{year}_{lat}_{lon}"
elif len(high_temperature) == 1:
add_on = f"_{year}_{lat}_{lon}_{high_temperature[0]}"
# additional parameters for heat_pump mode
factor_icing = (None if parameters.factor_icing == "None" else float(
parameters.factor_icing))
temp_threshold_icing = (None
if parameters.temp_threshold_icing == "None"
else float(parameters.temp_threshold_icing))
efficiency = cmpr_hp_chiller.calc_cops(
temp_high=high_temperature,
temp_low=low_temperature,
quality_grade=quality_grade,
mode=mode,
temp_threshold_icing=temp_threshold_icing,
factor_icing=factor_icing,
)
# define variables for later proceeding
column_name = "cop"
filename = f"cops_heat_pump{add_on}.csv"
elif mode == "chiller":
if len(low_temperature) > 1:
add_on = f"_{year}_{lat}_{lon}"
elif len(low_temperature) == 1:
add_on = f"_{year}_{lat}_{lon}_{low_temperature[0]}"
efficiency = cmpr_hp_chiller.calc_cops(
temp_high=high_temperature,
temp_low=low_temperature,
quality_grade=quality_grade,
mode=mode,
)
column_name = "eer"
filename = f"eers_chiller{add_on}.csv"
# add list of cops/eers to data frame
df = pd.DataFrame(weather[temperature_col])
try:
df[column_name] = efficiency
except ValueError:
df[column_name] = np.multiply(efficiency, np.ones(len(df)))
# set negative COPs/EERs to np.inf
# COP/EER below zero results from temp_low > temp_high
# and will therefore be represented with COP/EER -> infinity
indices = df.loc[df[column_name] < 0].index
df[column_name][indices] = np.inf
# extract COPs/EERs as pd.Series from data frame
efficiency_series = df[column_name]
efficiency_series.name = "no_unit"
# save time series to `user_inputs_mvs_directory/time_series`
time_series_directory = os.path.join(user_inputs_mvs_directory,
"time_series")
logging.info(
f"The cops of a heat pump are calculated and saved under {time_series_directory}."
)
efficiency_series.to_csv(os.path.join(time_series_directory, filename),
index=False,
header=True)
return efficiency_series
"""
Example on how to use the 'calc_cops' function to get the
COPs of a compression chiller.
We use the ambient air as heat sink (high temperature reservoir). The input is
a list to show how the function can be applied on several time steps. The
output is a list as well and may serve as input (conversion_factor) for a
oemof.solph.transformer.
"""
import oemof.thermal.compression_heatpumps_and_chillers as cmpr_hp_chiller
# Ambient temperatures in degC for a single day (24h)
temp_ambient = [
24, 24, 24, 25, 25, 25, 26, 27, 28, 29, 31, 32, 35, 34, 27, 26, 25, 24, 24,
24, 24, 24, 24, 23
]
cops_chiller = cmpr_hp_chiller.calc_cops(temp_high=temp_ambient,
temp_low=[18],
quality_grade=0.3,
mode='chiller')
print("")
print("Coefficients of Performance (COP):")
t = 1
for cop_chiller in cops_chiller:
print(t, "h: {:2.2f}".format(cop_chiller))
t += 1
print("")
def test_cop_calculation_chiller():
cops_chiller = cmpr_hp_chllr.calc_cops(temp_high=[35],
temp_low=[17],
quality_grade=0.45,
mode='chiller')
assert cops_chiller == [7.25375]
"""
Example on how to use the 'calc_cops' function to get the
COPs of an exemplary ground-source heat pump (GSHP).
We use the soil temperature as low temperature heat reservoir.
"""
import oemof.thermal.compression_heatpumps_and_chillers as cmpr_hp_chiller
import pandas as pd
import os
# set path
path_data= r'C:\Users\Stefanie.nguyen\git\COP_calculation\oemof-thermal\examples\compression_heatpump_and_chiller'
# Precalculation of COPs
cops_GSHP = cmpr_hp_chiller.calc_cops(
temp_high=[37.43],
temp_low=[10],
quality_grade=0.53,
mode='heat_pump')
GSHP_dict={'ground_temperature':[10],
'temperature_sink':[37.43],
'COP':cops_GSHP}
data=pd.DataFrame(GSHP_dict)
#data.to_csv(os.path.join(os.path.dirname(__file__) , 'data/results/2021-03-16_GSHP_COP.csv'))
def test_cop_calculation_hp_list_input_02():
cops_HP = cmpr_hp_chllr.calc_cops(temp_high=[40],
temp_low=[12, 12],
quality_grade=0.4,
mode='heat_pump')
assert cops_HP == [4.473571428571428, 4.473571428571428]
# Borehole that acts as heat source for the heat pump with
# limited extraction heat flow rate
energysystem.add(
solph.Source(label='ambient',
outputs={b_th_low: solph.Flow(nominal_value=30)}))
energysystem.add(
solph.Sink(label='demand',
inputs={
b_th_high: solph.Flow(fix=data['demand_heat'],
nominal_value=1)
}))
# Precalculation of COPs
cops_GSHP = cmpr_hp_chiller.calc_cops(temp_high=[40],
temp_low=data['ground_temperature'],
quality_grade=0.4,
mode='heat_pump')
# Ground-Source Heat Pump
energysystem.add(
solph.Transformer(
label="GSHP",
inputs={
b_el: solph.Flow(),
b_th_low: solph.Flow()
},
outputs={b_th_high: solph.Flow(nominal_value=25, variable_costs=5)},
conversion_factors={
b_el: [1 / cop for cop in cops_GSHP],
b_th_low: [(cop - 1) / cop for cop in cops_GSHP]
}))
label='backup_heating',
outputs={b_heat: solph.Flow(variable_costs=10)}))
energysystem.add(solph.Sink(
label='demand',
inputs={b_heat: solph.Flow(actual_value=data['demand_heat'],
fixed=True,
nominal_value=1)}))
temp_threshold_icing = 2
# Pre-Calculate COPs
cops_ASHP = cmpr_hp_chiller.calc_cops(
temp_high=[40],
temp_low=data['ambient_temperature'],
quality_grade=0.4,
mode='heat_pump',
consider_icing=True,
temp_threshold_icing=temp_threshold_icing,
factor_icing=0.8)
# Air-Source Heat Pump
energysystem.add(solph.Transformer(
label="ASHP",
inputs={b_el: solph.Flow()},
outputs={b_heat: solph.Flow(nominal_value=25, variable_costs=5)},
conversion_factors={b_heat: cops_ASHP}))
model = solph.Model(energysystem)
model.solve(solver=solver, solve_kwargs={'tee': solver_verbose})
def __init__(self, params):
"""Constructor method
"""
# Call the init function of the mother class.
Component.__init__(self)
# ------------------- PARAMETERS -------------------
self.name = 'Heat_pump_default_name'
self.bus_el = None
self.bus_th = None
# Max. heating output [W]
self.power_max = 1000e3
# Life time [a]
self.life_time = 20
self.csv_filename = None
self.csv_separator = ','
self.column_title = 0
self.path = os.path.dirname(__file__)
# ------------------- PARAMETERS BASED ON OEMOF THERMAL EXAMPLE -------------------
# Temperature below which icing occurs [K]
self.temp_threshold_icing = 275.15
# Convert to degrees C for oemof_thermal function
self.temp_threshold_icing_C = self.temp_threshold_icing - 273.15
# The output temperature from the heat pump [K]
self.temp_high = 313.15
# Convert to degrees C for oemof_thermal function
self.temp_high_C = self.temp_high - 273.15
# Convert to a list for oemof_thermal function
self.temp_high_C_list = [self.temp_high_C]
# The ambient temperature [K]
self.temp_low = 283.15
# Convert to degrees C for oemof_thermal function
self.temp_low_C = self.temp_low - 273.15
# Quality grade of heat pump [-]
self.quality_grade = 0.4
# Can be set to heat pump or chiller
self.mode = 'heat_pump'
# COP reduction caused by icing [-]
self.factor_icing = 0.8
# Ask Jann about this/look more into detail
# self.consider_icing = False
# ------------------- UPDATE PARAMETER DEFAULT VALUES -------------------
self.set_parameters(params)
if self.csv_filename is not None:
# A csv file containing data for the ambient temperature is required [deg C]
self.temp_low = func.read_data_file(self.path, self.csv_filename,
self.csv_separator,
self.column_title)
self.temp_low_series = self.temp_low[self.column_title]
self.temp_low_series_C = pd.Series(self.temp_low_series - 273.15)
else:
self.temp_low_list = [self.temp_low_C
] * self.sim_params.n_intervals
self.temp_low_series_C = pd.Series(self.temp_low_list)
# A function taken from oemof thermal that calculates the coefficient
# of performance (pre-calculated)
self.cops = cmpr_hp_chiller.calc_cops(
self.mode,
self.temp_high_C_list,
self.temp_low_series_C,
self.quality_grade,
self.temp_threshold_icing_C,
# self.consider_icing,
self.factor_icing)
data_reduct = data.loc['2016-01-01 00:00:00':'2017-01-01 00:00:00'].reset_index()
#print(data_reduct)
else:
raise Exception('Date time range does not exist. Please try another data set.')
dataframe = pd.concat([data_reduct['date_time'],
data_reduct['ambient_temperature'],
data_reduct['temperature_sink']], axis=1).set_index('date_time')
#if ambient temperature is higher than 20°C, set temperature sinks to 46.9°C for warm water use only
dataframe.loc[dataframe.ambient_temperature > 20, 'temperature_sink'] = 46.9
# Precalculation of COPs
cops_ASHP = cmpr_hp_chiller.calc_cops(
temp_high=dataframe['temperature_sink'],
temp_low=dataframe['ambient_temperature'],
quality_grade=0.4030,
mode='heat_pump')
COP=pd.DataFrame(cops_ASHP, data_reduct['date_time'], columns=['COP'])
#pre processing sink temperature
list_temp_low = dataframe['ambient_temperature'].values.tolist() # External temperature of evaporator
list_temp_medium = dataframe['temperature_sink'].values.tolist() # External temperature of condenser
# Calculate temperature difference between condenser and evaporator
temp_diff = [(t_m - t_l) for (t_m, t_l) in zip(list_temp_medium, list_temp_low)]
temp_diff_dataframe = pd.DataFrame(temp_diff, data_reduct['date_time'], columns=['temp_diff'])
#Concatenate final data and save
COP_data=pd.concat([dataframe, COP, temp_diff_dataframe], axis=1)