def calc_heat_loads_central_ac(bpr, t, tsd):
"""
Procedure for hourly heating system load calculation for a building with a central AC heating system.
Gabriel Happle, February 2018
:param bpr: building properties row object
:param t: time step / hour of year [0..8760]
:param tsd: time series data dict
:return:
"""
# (0) Extract values from tsd
# get values from tsd
m_ve_mech = tsd['m_ve_mech'][t]
t_ve_mech_after_hex = tsd['theta_ve_mech'][t]
x_ve_mech = tsd['x_ve_mech'][t]
t_int_prev = tsd['T_int'][t - 1]
ta_hs_set = tsd['ta_hs_set'][t]
# (1) The RC-model gives the sensible energy demand for the hour
# calc rc model sensible demand
qh_sen_rc_demand, rc_model_temperatures = calc_rc_heating_demand(
bpr, tsd, t)
# (2) The load of the central AC unit is determined by the air mass flows and fixed supply temperature
# calc central ac unit load
system_loads_ahu = airconditioning_model.central_air_handling_unit_heating(
m_ve_mech, t_ve_mech_after_hex, x_ve_mech, ta_hs_set, t_int_prev, bpr)
qh_sen_central_ac_load = system_loads_ahu['qh_sen_ahu']
# (3) Check demand vs. central AC heating load
# check for over heating
if qh_sen_central_ac_load > qh_sen_rc_demand >= 0.0:
# case: over heating
qh_sen_aru = 0.0 # no additional heating via air recirculation unit
# update rc model temperatures
rc_model_temperatures = rc_model_SIA.calc_rc_model_temperatures_heating(
qh_sen_central_ac_load, bpr, tsd, t)
# ARU values to tsd
ma_sup_hs_aru = 0.0
ta_sup_hs_aru = np.nan
ta_re_hs_aru = np.nan
tsd['sys_status_aru'][t] = 'Off'
tsd['sys_status_ahu'][t] = 'On:over heating'
elif 0.0 <= qh_sen_central_ac_load < qh_sen_rc_demand:
# case: additional heating by air recirculation unit
qh_sen_aru = qh_sen_rc_demand - qh_sen_central_ac_load
# calc recirculation air mass flows
system_loads_aru = airconditioning_model.local_air_recirculation_unit_heating(
qh_sen_aru, t_int_prev, bpr)
# update of rc model not necessary
ma_sup_hs_aru = system_loads_aru['ma_sup_hs_aru']
ta_sup_hs_aru = system_loads_aru['ta_sup_hs_aru']
ta_re_hs_aru = system_loads_aru['ta_re_hs_aru']
tsd['sys_status_aru'][t] = 'On'
# check status of ahu
if qh_sen_central_ac_load > 0.0:
tsd['sys_status_ahu'][t] = 'On'
elif qh_sen_central_ac_load == 0.0:
tsd['sys_status_ahu'][t] = 'Off'
# this state happens during sensible demand but zero mechanical ventilation air flow
# (= sufficient infiltration)
elif 0.0 == qh_sen_central_ac_load == qh_sen_rc_demand:
# everything off
qh_sen_aru = 0.0
ma_sup_hs_aru = 0.0
ta_sup_hs_aru = np.nan
ta_re_hs_aru = np.nan
tsd['sys_status_aru'][t] = 'Off'
tsd['sys_status_ahu'][t] = 'Off'
else:
raise Exception(
"Something went wrong in the central AC heating load calculation.")
# act on humidity
tsd['T_int'][t] = rc_model_temperatures[
'T_int'] # humidification load needs zone temperature
g_hu_ld = latent_loads.calc_humidification_moisture_load(
bpr, tsd, t) # calc local humidification load
tsd['Ehs_lat_aux'][t] = airconditioning_model.electric_humidification_unit(
g_hu_ld, m_ve_mech) # calc electricity of humidification unit
tsd['g_hu_ld'][t] = g_hu_ld # humidification
tsd['g_dhu_ld'][t] = 0.0 # no dehumidification
latent_loads.calc_moisture_content_in_zone_local(
bpr, tsd, t) # calculate moisture in zone
# write sensible loads to tsd
tsd['Qhs_sen_rc'][t] = qh_sen_rc_demand
tsd['Qhs_sen_shu'][t] = 0.0
tsd['sys_status_sen'][t] = 'no system'
tsd['Qhs_sen_ahu'][t] = qh_sen_central_ac_load
tsd['Qhs_sen_aru'][t] = qh_sen_aru
rc_temperatures_to_tsd(rc_model_temperatures, tsd, t)
tsd['Qhs_sen_sys'][
t] = qh_sen_central_ac_load + qh_sen_aru # sum system loads
tsd['Qhs_lat_sys'][t] = 0.0
# mass flows to tsd
tsd['ma_sup_hs_ahu'][t] = system_loads_ahu['ma_sup_hs_ahu']
tsd['ta_sup_hs_ahu'][t] = system_loads_ahu['ta_sup_hs_ahu']
tsd['ta_re_hs_ahu'][t] = system_loads_ahu['ta_re_hs_ahu']
tsd['ma_sup_hs_aru'][t] = ma_sup_hs_aru
tsd['ta_sup_hs_aru'][t] = ta_sup_hs_aru
tsd['ta_re_hs_aru'][t] = ta_re_hs_aru
# emission losses
q_em_ls_heating = space_emission_systems.calc_q_em_ls_heating(bpr, tsd, t)
tsd['Qhs_em_ls'][t] = q_em_ls_heating
# the return is only for the input into the detailed thermal reverse calculations for the dashboard graphs
return rc_model_temperatures
def calc_rc_heating_demand(bpr, tsd, t):
"""
Crank-Nicholson Procedure to calculate heating / cooling demand of buildings
following the procedure in 2.3.2 in SIA 2044 / Korrigenda C1 zum Merkblatt SIA 2044:2011
/ Korrigenda C2 zum Mekblatt SIA 2044:2011
Special procedures for updating ventilation air AC-heated and AC-cooled buildings
Author: Gabriel Happle
Date: 01/2017
:param bpr: building properties row object
:param tsd: time series data dict
:param t: time step / hour of year [0..8760]
:return: phi_h_act, rc_model_temperatures
"""
# following the procedure in 2.3.2 in SIA 2044 / Korrigenda C1 zum Merkblatt SIA 2044:2011
# / Korrigenda C2 zum Mekblatt SIA 2044:2011
# STEP 1
# ******
# calculate temperatures with 0 heating power
rc_model_temperatures_0 = rc_model_SIA.calc_rc_model_temperatures_no_heating_cooling(
bpr, tsd, t)
t_int_0 = rc_model_temperatures_0['T_int']
# CHECK FOR DEMAND
if not rc_model_SIA.has_sensible_heating_demand(t_int_0, tsd, t):
# return zero demand
rc_model_temperatures = rc_model_temperatures_0
phi_h_act = 0.0
elif rc_model_SIA.has_sensible_heating_demand(t_int_0, tsd, t):
# continue
# STEP 2
# ******
# calculate temperatures with 10 W/m2 heating power
phi_hc_10 = 10.0 * bpr.rc_model['Af']
rc_model_temperatures_10 = rc_model_SIA.calc_rc_model_temperatures_heating(
phi_hc_10, bpr, tsd, t)
t_int_10 = rc_model_temperatures_10['T_int']
t_int_set = tsd['ta_hs_set'][t]
# interpolate heating power
# (64) in SIA 2044 / Korrigenda C1 zum Merkblatt SIA 2044:2011 / Korrigenda C2 zum Mekblatt SIA 2044:2011
phi_hc_ul = phi_hc_10 * (t_int_set - t_int_0) / (t_int_10 - t_int_0)
# STEP 3
# ******
# check if available power is sufficient
phi_h_max = bpr.hvac['Qhsmax_Wm2'] * bpr.rc_model['Af']
if 0.0 < phi_hc_ul <= phi_h_max:
# case heating with phi_hc_ul
# calculate temperatures with this power
phi_h_act = phi_hc_ul
elif 0.0 < phi_hc_ul > phi_h_max:
# case heating with max power available
# calculate temperatures with this power
phi_h_act = phi_h_max
else:
raise Exception("Unexpected status in 'calc_rc_heating_demand'")
# STEP 4
# ******
rc_model_temperatures = rc_model_SIA.calc_rc_model_temperatures_heating(
phi_h_act, bpr, tsd, t)
else:
raise Exception("Unexpected status in 'calc_rc_heating_demand'")
return phi_h_act, rc_model_temperatures
def calc_rc_model_demand_heating_cooling(bpr, tsd, t, gv):
"""
Crank-Nicholson Procedure to calculate heating / cooling demand of buildings
following the procedure in 2.3.2 in SIA 2044 / Korrigenda C1 zum Merkblatt SIA 2044:2011 / Korrigenda C2 zum Mekblatt SIA 2044:2011
Special procedures for updating ventilation air AC-heated and AC-cooled buildings
Author: Gabriel Happle
Date: 01/2017
:param bpr: building properties row object
:param tsd: time series data dict
:param t: time step / hour of year [0..8760]
:param gv: globalvars
:return: updates values in tsd
"""
# following the procedure in 2.3.2 in SIA 2044 / Korrigenda C1 zum Merkblatt SIA 2044:2011
# / Korrigenda C2 zum Mekblatt SIA 2044:2011
# ++++++++++++++++++++++++++++++
# CASE 0 - NO HEATING OR COOLING
# ++++++++++++++++++++++++++++++
if not control_heating_cooling_systems.is_active_heating_system(bpr, tsd, t) \
and not control_heating_cooling_systems.is_active_cooling_system(bpr, tsd, t):
# STEP 1
# ******
# calculate temperatures
rc_model_temperatures = rc_model_SIA.calc_rc_model_temperatures_no_heating_cooling(
bpr, tsd, t)
# write to tsd
tsd['theta_a'][t] = rc_model_temperatures['theta_a']
tsd['theta_m'][t] = rc_model_temperatures['theta_m']
tsd['theta_c'][t] = rc_model_temperatures['theta_c']
tsd['theta_o'][t] = rc_model_temperatures['theta_o']
update_tsd_no_cooling(tsd, t)
update_tsd_no_heating(tsd, t)
tsd['system_status'][t] = 'systems off'
# ++++++++++++++++
# CASE 1 - HEATING
# ++++++++++++++++
elif control_heating_cooling_systems.is_active_heating_system(bpr, tsd, t):
# case for heating
tsd['system_status'][t] = 'Radiative heating'
# STEP 1
# ******
# calculate temperatures with 0 heating power
rc_model_temperatures_0 = rc_model_SIA.calc_rc_model_temperatures_no_heating_cooling(
bpr, tsd, t)
theta_a_0 = rc_model_temperatures_0['theta_a']
# STEP 2
# ******
# calculate temperatures with 10 W/m2 heating power
phi_hc_10 = 10 * bpr.rc_model['Af']
rc_model_temperatures_10 = rc_model_SIA.calc_rc_model_temperatures_heating(
phi_hc_10, bpr, tsd, t)
theta_a_10 = rc_model_temperatures_10['theta_a']
theta_a_set = tsd['ta_hs_set'][t]
# interpolate heating power
# (64) in SIA 2044 / Korrigenda C1 zum Merkblatt SIA 2044:2011 / Korrigenda C2 zum Mekblatt SIA 2044:2011
phi_hc_ul = phi_hc_10 * (theta_a_set - theta_a_0) / (theta_a_10 -
theta_a_0)
# STEP 3
# ******
# check if available power is sufficient
phi_h_max = bpr.hvac['Qhsmax_Wm2'] * bpr.rc_model['Af']
if 0 < phi_hc_ul <= phi_h_max:
# case heating with phi_hc_ul
# calculate temperatures with this power
phi_h_act = phi_hc_ul
elif 0 < phi_hc_ul > phi_h_max:
# case heating with max power available
# calculate temperatures with this power
phi_h_act = phi_h_max
else:
raise
# STEP 4
# ******
rc_model_temperatures = rc_model_SIA.calc_rc_model_temperatures_heating(
phi_h_act, bpr, tsd, t)
# write necessary parameters for AC calculation to tsd
tsd['theta_a'][t] = rc_model_temperatures['theta_a']
tsd['theta_m'][t] = rc_model_temperatures['theta_m']
tsd['theta_c'][t] = rc_model_temperatures['theta_c']
tsd['theta_o'][t] = rc_model_temperatures['theta_o']
tsd['Qhs_sen'][t] = phi_h_act
tsd['Qhs_sen_sys'][t] = phi_h_act
tsd['Qhs_lat_sys'][t] = 0
tsd['Ehs_lat_aux'][t] = 0
tsd['ma_sup_hs'][t] = 0
tsd['Ta_sup_hs'][t] = 0
tsd['Ta_re_hs'][t] = 0
tsd['m_ve_recirculation'][t] = 0
# STEP 5 - latent and sensible heat demand of AC systems
# ******
if control_heating_cooling_systems.heating_system_is_ac(bpr):
air_con_model_loads_flows_temperatures = airconditioning_model.calc_hvac_heating(
tsd, t, gv)
tsd['system_status'][t] = 'AC heating'
# update temperatures for over heating case
if air_con_model_loads_flows_temperatures[
'q_hs_sen_hvac'] > phi_h_act:
phi_h_act_over_heating = air_con_model_loads_flows_temperatures[
'q_hs_sen_hvac']
rc_model_temperatures = rc_model_SIA.calc_rc_model_temperatures_heating(
phi_h_act_over_heating, bpr, tsd, t)
# update temperatures
tsd['theta_a'][t] = rc_model_temperatures['theta_a']
tsd['theta_m'][t] = rc_model_temperatures['theta_m']
tsd['theta_c'][t] = rc_model_temperatures['theta_c']
tsd['theta_o'][t] = rc_model_temperatures['theta_o']
tsd['system_status'][t] = 'AC over heating'
# update AC energy demand
tsd['Qhs_sen_sys'][t] = air_con_model_loads_flows_temperatures[
'q_hs_sen_hvac']
tsd['Qhs_lat_sys'][t] = air_con_model_loads_flows_temperatures[
'q_hs_lat_hvac']
tsd['ma_sup_hs'][t] = air_con_model_loads_flows_temperatures[
'ma_sup_hs']
tsd['Ta_sup_hs'][t] = air_con_model_loads_flows_temperatures[
'ta_sup_hs']
tsd['Ta_re_hs'][t] = air_con_model_loads_flows_temperatures[
'ta_re_hs']
tsd['Ehs_lat_aux'][t] = air_con_model_loads_flows_temperatures[
'e_hs_lat_aux']
tsd['m_ve_recirculation'][
t] = air_con_model_loads_flows_temperatures[
'm_ve_hvac_recirculation']
# STEP 6 - emission system losses
# ******
q_em_ls_heating = space_emission_systems.calc_q_em_ls_heating(
bpr, tsd, t)
# set temperatures to tsd for heating
tsd['theta_a'][t] = rc_model_temperatures['theta_a']
tsd['theta_m'][t] = rc_model_temperatures['theta_m']
tsd['theta_c'][t] = rc_model_temperatures['theta_c']
tsd['theta_o'][t] = rc_model_temperatures['theta_o']
tsd['Qhs_lat_sys'][t] = 0
tsd['Qhs_em_ls'][t] = q_em_ls_heating
tsd['Qhs_sen'][t] = phi_h_act
tsd['Qhsf'][t] = 0
tsd['Qhsf_lat'][t] = 0
update_tsd_no_cooling(tsd, t)
# ++++++++++++++++
# CASE 2 - COOLING
# ++++++++++++++++
elif control_heating_cooling_systems.is_active_cooling_system(bpr, tsd, t):
# case for cooling
tsd['system_status'][t] = 'Radiative cooling'
# STEP 1
# ******
# calculate temperatures with 0 heating power
rc_model_temperatures_0 = rc_model_SIA.calc_rc_model_temperatures_no_heating_cooling(
bpr, tsd, t)
theta_a_0 = rc_model_temperatures_0['theta_a']
# STEP 2
# ******
# calculate temperatures with 10 W/m2 cooling power
phi_hc_10 = 10 * bpr.rc_model['Af']
rc_model_temperatures_10 = rc_model_SIA.calc_rc_model_temperatures_cooling(
phi_hc_10, bpr, tsd, t)
theta_a_10 = rc_model_temperatures_10['theta_a']
theta_a_set = tsd['ta_cs_set'][t]
# interpolate heating power
# (64) in SIA 2044 / Korrigenda C1 zum Merkblatt SIA 2044:2011 / Korrigenda C2 zum Mekblatt SIA 2044:2011
phi_hc_ul = phi_hc_10 * (theta_a_set - theta_a_0) / (theta_a_10 -
theta_a_0)
# STEP 3
# ******
# check if available power is sufficient
phi_c_max = -bpr.hvac['Qcsmax_Wm2'] * bpr.rc_model['Af']
if 0 > phi_hc_ul >= phi_c_max:
# case heating with phi_hc_ul
# calculate temperatures with this power
phi_c_act = phi_hc_ul
elif 0 > phi_hc_ul < phi_c_max:
# case heating with max power available
# calculate temperatures with this power
phi_c_act = phi_c_max
else:
raise
# STEP 4
# ******
rc_model_temperatures = rc_model_SIA.calc_rc_model_temperatures_cooling(
phi_c_act, bpr, tsd, t)
# write necessary parameters for AC calculation to tsd
tsd['theta_a'][t] = rc_model_temperatures['theta_a']
tsd['theta_m'][t] = rc_model_temperatures['theta_m']
tsd['theta_c'][t] = rc_model_temperatures['theta_c']
tsd['theta_o'][t] = rc_model_temperatures['theta_o']
tsd['Qcs_sen'][t] = phi_c_act
tsd['Qcs_sen_sys'][t] = phi_c_act
tsd['Qcs_lat_sys'][t] = 0
tsd['ma_sup_cs'][t] = 0
tsd['m_ve_recirculation'][t] = 0
# STEP 5 - latent and sensible heat demand of AC systems
# ******
if control_heating_cooling_systems.cooling_system_is_ac(bpr):
tsd['system_status'][t] = 'AC cooling'
air_con_model_loads_flows_temperatures = airconditioning_model.calc_hvac_cooling(
tsd, t, gv)
# update temperatures for over cooling case
if air_con_model_loads_flows_temperatures[
'q_cs_sen_hvac'] < phi_c_act:
phi_c_act_over_cooling = air_con_model_loads_flows_temperatures[
'q_cs_sen_hvac']
rc_model_temperatures = rc_model_SIA.calc_rc_model_temperatures_cooling(
phi_c_act_over_cooling, bpr, tsd, t)
# update temperatures
tsd['theta_a'][t] = rc_model_temperatures['theta_a']
tsd['theta_m'][t] = rc_model_temperatures['theta_m']
tsd['theta_c'][t] = rc_model_temperatures['theta_c']
tsd['theta_o'][t] = rc_model_temperatures['theta_o']
tsd['system_status'][t] = 'AC over cooling'
# update AC energy demand
tsd['Qcs_sen_sys'][t] = air_con_model_loads_flows_temperatures[
'q_cs_sen_hvac']
tsd['Qcs_lat_sys'][t] = air_con_model_loads_flows_temperatures[
'q_cs_lat_hvac']
tsd['ma_sup_cs'][t] = air_con_model_loads_flows_temperatures[
'ma_sup_cs']
tsd['Ta_sup_cs'][t] = air_con_model_loads_flows_temperatures[
'ta_sup_cs']
tsd['Ta_re_cs'][t] = air_con_model_loads_flows_temperatures[
'ta_re_cs']
tsd['m_ve_recirculation'][
t] = air_con_model_loads_flows_temperatures[
'm_ve_hvac_recirculation']
# STEP 6 - emission system losses
# ******
q_em_ls_cooling = space_emission_systems.calc_q_em_ls_cooling(
bpr, tsd, t)
# set temperatures to tsd for heating
tsd['theta_a'][t] = rc_model_temperatures['theta_a']
tsd['theta_m'][t] = rc_model_temperatures['theta_m']
tsd['theta_c'][t] = rc_model_temperatures['theta_c']
tsd['theta_o'][t] = rc_model_temperatures['theta_o']
tsd['Qcs'][t] = 0
tsd['Qcs_em_ls'][t] = q_em_ls_cooling
tsd['Qcsf'][t] = 0
tsd['Qcsf_lat'][t] = 0
update_tsd_no_heating(tsd, t)
return
