def test_enthalpy_moist_air(self):
"""Check the enthalpy of humid air."""
from psychrochart.equations import (
PRESSURE_STD_ATM_KPA, saturation_pressure_water_vapor,
humidity_ratio, enthalpy_moist_air)
# From http://www.engineeringtoolbox.com/enthalpy-moist-air-d_683.html
# Check the enthalpy of humid air at 25ºC with specific
# moisture content x = 0.0203 kg/kg (saturation).
press = PRESSURE_STD_ATM_KPA
dry_temp_c, w_kg_kga = 25, 0.0203
p_sat = saturation_pressure_water_vapor(dry_temp_c)
w_max = humidity_ratio(p_sat, press)
ratio_humid = w_kg_kga / w_max
p_w_kpa = ratio_humid * p_sat
h_m = enthalpy_moist_air(dry_temp_c, p_w_kpa, press)
h_m_bis = enthalpy_moist_air(dry_temp_c, p_w_kpa, press)
self.assertEqual(h_m, h_m_bis)
self.assertEqual(round(h_m, 1), 76.9)
def Qest(self):
"""Carga de refrigeração sensível e latente para fluxo de ar
estabelecido kW"""
import psychrochart.equations as pce
area_p = self.h_porta * self.l_porta
tbs = self.temp_externa('tbs')
tbu = self.temp_externa('tbu')
h_externo = pce.humidity_ratio_from_temps(tbs, tbu)
w_externo = pce.water_vapor_pressure(h_externo)
hi = pce.enthalpy_moist_air(tbs, w_externo)
t_estoc = self.dados_produto('T Estoc')
u_estoc = self.dados_produto('UR')
t_bu_refri = pce.wet_bulb_temperature_empiric(t_estoc, u_estoc)
h_refri = pce.humidity_ratio_from_temps(t_estoc, t_bu_refri)
w_refri = pce.water_vapor_pressure(h_refri)
hr = pce.enthalpy_moist_air(t_estoc, w_refri)
pi = 1 / pce.specific_volume(tbs, w_externo)
pr = 1 / pce.specific_volume(t_estoc, w_refri)
Fm = (2 / (1 + (pr / pi)**(1 / 3)))**1.5
Uest = 0.442 * Fm * ((pr - pi) * 9.81 * self.h_porta / pr)**0.5
Qest = 0.5 * area_p * (hi - hr) * pr * Uest
return Qest
def _make_chart_data(self,
styles: Union[dict, str]=None,
zones_file: Union[dict, str]=None) -> None:
"""Generate the data to plot the psychrometric chart."""
# Get styling
config = load_config(styles)
self.d_config = config
self.temp_step = config['limits']['step_temp']
self.figure_params = config['figure']
self.dbt_min, self.dbt_max = config['limits']['range_temp_c']
self.w_min, self.w_max = config['limits']['range_humidity_g_kg']
self.chart_params = config['chart_params']
# Base pressure
if config['limits'].get('pressure_kpa') is not None:
self.p_atm_kpa = config['limits']['pressure_kpa']
elif config['limits'].get('altitude_m') is not None:
self.altitude_m = config['limits']['altitude_m']
self.p_atm_kpa = pressure_by_altitude(self.altitude_m)
# Dry bulb constant lines (vertical):
if self.chart_params["with_constant_dry_temp"]:
step = self.chart_params["constant_temp_step"]
style = config['constant_dry_temp']
temps_vl = f_range(self.dbt_min, self.dbt_max, step)
heights = [1000 * humidity_ratio(
saturation_pressure_water_vapor(t),
p_atm_kpa=self.p_atm_kpa) for t in temps_vl]
self.constant_dry_temp_data = PsychroCurves(
[PsychroCurve([t, t], [self.w_min, h], style,
type_curve='constant_dry_temp_data',
label=None, logger=self._logger)
for t, h in zip(temps_vl, heights)],
family_label=self.chart_params["constant_temp_label"])
# Absolute humidity constant lines (horizontal):
if self.chart_params["with_constant_humidity"]:
step = self.chart_params["constant_humid_step"]
style = config['constant_humidity']
ws_hl = f_range(self.w_min + step, self.w_max + step / 10, step)
dew_points = solve_curves_with_iteration(
'DEW POINT', [x / 1000 for x in ws_hl],
lambda x: dew_point_temperature(
water_vapor_pressure(
x, p_atm_kpa=self.p_atm_kpa)),
lambda x: humidity_ratio(
saturation_pressure_water_vapor(x),
p_atm_kpa=self.p_atm_kpa))
self.constant_humidity_data = PsychroCurves(
[PsychroCurve([t_dp, self.dbt_max], [w, w], style,
type_curve='constant_humidity_data',
label=None, logger=self._logger)
for w, t_dp in zip(ws_hl, dew_points)],
family_label=self.chart_params["constant_humid_label"])
# Constant relative humidity curves:
if self.chart_params["with_constant_rh"]:
rh_perc_values = self.chart_params["constant_rh_curves"]
rh_label_values = self.chart_params.get("constant_rh_labels", [])
label_loc = self.chart_params.get("constant_rh_labels_loc", .85)
style = config["constant_rh"]
temps_ct_rh, curves_ct_rh = _gen_list_curves_range_temps(
curve_constant_humidity_ratio,
self.dbt_min, self.dbt_max, self.temp_step,
rh_perc_values, p_atm_kpa=self.p_atm_kpa)
self.constant_rh_data = PsychroCurves(
[PsychroCurve(
temps_ct_rh, curve_ct_rh, style,
type_curve='constant_rh_data',
label_loc=label_loc, label='RH {:g} %'.format(rh)
if round(rh, 1) in rh_label_values else None,
logger=self._logger)
for rh, curve_ct_rh in zip(rh_perc_values, curves_ct_rh)],
family_label=self.chart_params["constant_rh_label"])
# Constant enthalpy lines:
if self.chart_params["with_constant_h"]:
step = self.chart_params["constant_h_step"]
start, end = self.chart_params["range_h"]
enthalpy_values = f_range(start, end, step)
h_label_values = self.chart_params.get("constant_h_labels", [])
label_loc = self.chart_params.get("constant_h_labels_loc", 1.)
style = config["constant_h"]
temps_max_constant_h = [
dry_temperature_for_enthalpy_of_moist_air(
self.w_min / 1000, h)
for h in enthalpy_values]
sat_points = solve_curves_with_iteration(
'ENTHALPHY', enthalpy_values,
lambda x: dry_temperature_for_enthalpy_of_moist_air(
self.w_min / 1000 + 0.1, x),
lambda x: enthalpy_moist_air(
x, saturation_pressure_water_vapor(x),
p_atm_kpa=self.p_atm_kpa))
self.constant_h_data = PsychroCurves(
[PsychroCurve(
[t_sat, t_max], [1000 * humidity_ratio(
saturation_pressure_water_vapor(t_sat),
self.p_atm_kpa), self.w_min], style,
type_curve='constant_h_data',
label_loc=label_loc, label='{:g} kJ/kg_da'.format(h)
if round(h, 3) in h_label_values else None,
logger=self._logger)
for t_sat, t_max, h in zip(
sat_points, temps_max_constant_h, enthalpy_values)],
family_label=self.chart_params["constant_h_label"])
# Constant specific volume lines:
if self.chart_params["with_constant_v"]:
step = self.chart_params["constant_v_step"]
start, end = self.chart_params["range_vol_m3_kg"]
vol_values = f_range(start, end, step)
vol_label_values = self.chart_params.get("constant_v_labels", [])
label_loc = self.chart_params.get("constant_v_labels_loc", 1.)
style = config["constant_v"]
temps_max_constant_v = [
dry_temperature_for_specific_volume_of_moist_air(
0, specific_vol, p_atm_kpa=self.p_atm_kpa)
for specific_vol in vol_values]
sat_points = solve_curves_with_iteration(
'CONSTANT VOLUME', vol_values,
lambda x: dry_temperature_for_specific_volume_of_moist_air(
0, x, p_atm_kpa=self.p_atm_kpa),
lambda x: specific_volume(
x, saturation_pressure_water_vapor(x),
p_atm_kpa=self.p_atm_kpa))
self.constant_v_data = PsychroCurves(
[PsychroCurve(
[t_sat, t_max], [1000 * humidity_ratio(
saturation_pressure_water_vapor(t_sat),
self.p_atm_kpa), 0],
style, type_curve='constant_v_data',
label_loc=label_loc, label='{:g} m3/kg_da'.format(vol)
if round(vol, 3) in vol_label_values else None,
logger=self._logger)
for t_sat, t_max, vol in zip(
sat_points, temps_max_constant_v, vol_values)],
family_label=self.chart_params["constant_v_label"])
# Constant wet bulb temperature lines:
if self.chart_params["with_constant_wet_temp"]:
step = self.chart_params["constant_wet_temp_step"]
start, end = self.chart_params["range_wet_temp"]
wbt_values = f_range(start, end, step)
wbt_label_values = self.chart_params.get(
"constant_wet_temp_labels", [])
label_loc = self.chart_params.get(
"constant_wet_temp_labels_loc", .05)
style = config["constant_wet_temp"]
w_max_constant_wbt = [humidity_ratio(
saturation_pressure_water_vapor(wbt), self.p_atm_kpa)
for wbt in wbt_values]
self.constant_wbt_data = PsychroCurves(
[PsychroCurve(
[wbt, self.dbt_max],
[1000 * w_max,
1000 * humidity_ratio(
saturation_pressure_water_vapor(self.dbt_max)
* relative_humidity_from_temps(
self.dbt_max, wbt, p_atm_kpa=self.p_atm_kpa),
p_atm_kpa=self.p_atm_kpa)], style,
type_curve='constant_wbt_data',
label_loc=label_loc, label='{:g} °C'.format(wbt)
if wbt in wbt_label_values else None, logger=self._logger)
for wbt, w_max in zip(wbt_values, w_max_constant_wbt)],
family_label=self.chart_params["constant_wet_temp_label"])
# Saturation line:
if True:
sat_style = config["saturation"]
temps_sat_line, w_sat_line = _gen_list_curves_range_temps(
curve_constant_humidity_ratio,
self.dbt_min, self.dbt_max, self.temp_step, [100],
p_atm_kpa=self.p_atm_kpa)
self.saturation = PsychroCurves(
[PsychroCurve(
temps_sat_line, w_sat_line[0], sat_style,
type_curve='saturation', logger=self._logger)])
# Zones
if self.chart_params["with_zones"] or zones_file is not None:
self.append_zones(zones_file)
import psychrochart.equations as psc_e
# Temperatura de bulbo seco; pressao vapor
# entalpia = psc_e.enthalpy_moist_air()
# print(help(psc_e.specific_volume))
# print(help(psc_e.water_vapor_pressure))
# print(help(psc_e.enthalpy_moist_air))
# psc_e.relative_humidity_from_temps()
# print(help(psc_e.wet_bulb_temperature_empiric))
# print(help(psc_e.humidity_ratio_from_temps))
# t_bu_externo = psc_e.wet_bulb_temperature_empiric(33, 0.75)
hratio_externo = psc_e.humidity_ratio_from_temps(34, 26)
t_bu_refrig = psc_e.wet_bulb_temperature_empiric(-20.5, 0.925)
hratio_refrig = psc_e.humidity_ratio_from_temps(-20.5, t_bu_refrig)
w_v_pexterno = psc_e.water_vapor_pressure(hratio_externo)
w_v_prefrig = psc_e.water_vapor_pressure(hratio_refrig)
entalpia_externa = psc_e.enthalpy_moist_air(34, w_v_pexterno)
entalpia_refrigeracao = psc_e.enthalpy_moist_air(-20.5, w_v_prefrig)
densidade_refri = psc_e.specific_volume(-20.5, w_v_prefrig)
densidade_externo = psc_e.specific_volume(34, w_v_pexterno)
print("""Relação de humidade: {}
Pressão de vapor: {}
Entalpia do ar: {}
Volume específico: {}
Densidade: {}
""".format(hratio_externo, w_v_pexterno, entalpia_externa, densidade_externo,
1 / densidade_externo))