Use Heatpump to cool a bus cabin #493
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SimonKretz
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class Heat_Pump_Des():
# Method to design the heat pump
def __init__(self):
# define basic parameters
self.heat_source_T_des = 30.0
self.LFE_des = self.heat_source_T_des -5.0
self.LWC_des = 15
self.heatload_des = 25000.0
# The parameters that will vary for the different heat pump models are d
params_des = {'ref': 'R410a', 'm_air': 1, 'm_water': 0, 'ttd_u': 15}
self.nw = Network(fluids=[params_des['ref'], 'air', 'water'], T_unit='C', p_unit='bar',
h_unit='kJ / kg', m_unit='kg / s')
self.nw.set_attr(iterinfo=False)
# %% components
# sources & sinks
cool_closer = CycleCloser('coolant cycle closer')
cons_closer = CycleCloser('consumer cycle closer')
amb_in = Source('source ambient')
amb_out = Sink('sink ambient')
# ambient air system
apu = Pump('ambient pump')
# consumer system
cd = HeatExchanger('condenser') # Changed to a HeatExchanger in the case of cooling
crp = Pump('condenser recirculation pump')
cons = HeatExchangerSimple('consumer')
# evaporator system
va = Valve('valve')
dr = Drum('drum')
ev = HeatExchanger('evaporator')
erp = Pump('evaporator recirculation pump')
# compressor-system
cp1 = Compressor('compressor 1')
# %% connections
# consumer system
c_in_cd = Connection(cool_closer, 'out1', cd, 'in1')
close_crp = Connection(cons_closer, 'out1', crp, 'in1')
crp_ev = Connection(crp, 'out1', ev, 'in1') # TODO Rename
ev_cons = Connection(ev, 'out1', cons, 'in1') # TODO Rename
cons_close = Connection(cons, 'out1', cons_closer, 'in1')
self.nw.add_conns(c_in_cd, close_crp, crp_ev, ev_cons, cons_close)
# connection condenser - evaporator system
cd_va = Connection(cd, 'out1', va, 'in1')
self.nw.add_conns(cd_va)
# evaporator system
va_dr = Connection(va, 'out1', dr, 'in1')
dr_erp = Connection(dr, 'out1', erp, 'in1')
erp_ev = Connection(erp, 'out1', ev, 'in2')
ev_dr = Connection(ev, 'out2', dr, 'in2')
self.nw.add_conns(va_dr, dr_erp, erp_ev, ev_dr)
amb_in_apu = Connection(amb_in, 'out1', apu, 'in1')
cd_amb_out = Connection(cd, 'out2', amb_out, 'in1') # TODO Rename
self.nw.add_conns(amb_in_apu, cd_amb_out)
dr_cp1 = Connection(dr, 'out2', cp1, 'in1')
apu_cd = Connection(apu, 'out1', cd, 'in2') # TODO Rename
self.nw.add_conns(dr_cp1, apu_cd)
cp1_cc = Connection(cp1, 'out1', cool_closer, 'in1')
self.nw.add_conns(cp1_cc)
# %% component parametrization
# condenser system
cd.set_attr(pr1=0.99, pr2=0.99, ttd_u=params_des['ttd_u'], design=['pr2', 'ttd_u'],
offdesign=['zeta1','zeta2', 'kA_char'])
crp.set_attr(eta_s=0.8, design=['eta_s'], offdesign=['eta_s_char'])
cons.set_attr(pr=0.99, design=['pr'], offdesign=['zeta'])
# evaporator system
kA_char1 = ldc('heat exchanger', 'kA_char1', 'DEFAULT', CharLine)
kA_char2 = ldc('heat exchanger', 'kA_char2', 'EVAPORATING FLUID', CharLine)
ev.set_attr(pr1=0.99, pr2=0.99, ttd_l=5,
kA_char1=kA_char1, kA_char2=kA_char2,
design=['pr1', 'ttd_l'], offdesign=['zeta1', 'kA_char'])
erp.set_attr(eta_s=0.8, design=['eta_s'], offdesign=['eta_s_char'])
apu.set_attr(eta_s=0.8, design=['eta_s'], offdesign=['eta_s_char'])
# compressor system
cp1.set_attr(eta_s=0.8, design=['eta_s'], offdesign=['eta_s_char'])
# %% connection parametrization
# condenser system
c_in_cd.set_attr(p0=30, fluid={params_des['ref']: 1, 'water': 0,
'air': 0}
)
close_crp.set_attr(T=(self.LWC_des-5), p=1.5, fluid={params_des['ref']: 0, 'water': 1, 'air': 0},
offdesign=['m']
)
ev_cons.set_attr(T=self.LWC_des, design=['T'])
# evaporator system cold side
erp_ev.set_attr(m=Ref(va_dr, 1.15, 0))
# evaporator system hot side
# pumping at constant rate in partload
amb_in_apu.set_attr(T=self.heat_source_T_des, p=1,
fluid={params_des['ref']: 0, 'water': params_des['m_water'],
'air': params_des['m_air']
}
)
apu_cd.set_attr(p=1.0001) # check this
dr_cp1.set_attr(h0=400)
cd_amb_out.set_attr(T=self.LFE_des)
# %% key paramter
cons.set_attr(Q=self.heatload_des)
power_bus = Bus("Total power input")
heat_bus = Bus("Total heat production")
power_bus.add_comps(
{"comp": cp1, "base": "bus"},
{"comp": erp, "base": "bus"},
{"comp": apu, "base": "bus"},
{"comp": crp, "base": "bus"}
)
heat_bus.add_comps({"comp": cons})
self.nw.add_busses(power_bus, heat_bus)
# %% Calculation of the design condition
self.nw.solve('design')
# self.nw.print_results()
self.nw.save('heat_pump')
self.P_cons = self.nw.busses["Total power input"].P.val # TODO funktioniert berechnung der benötigten Leistung ?
self.COP = abs(self.heatload_des/self.P_cons)
print('COP ', self.COP)
def step(self, inputs):
self.skip_step = False
heat_source_T = inputs.get('heat_source_T')
if heat_source_T is not None:
self.heat_source_T = heat_source_T
T_amb = inputs.get('T_amb')
if T_amb is not None:
self.T_amb = T_amb
cond_in_T = inputs.get('cond_in_T')
if cond_in_T is not None:
self.cond_in_T = cond_in_T
Q_Demand = inputs.get('Q_Demand')
if Q_Demand is not None:
self.Q_Supplied = Q_Demand
self.nw.get_conn('source ambient:out1_ambient pump:in1').set_attr(T=self.heat_source_T)
self.nw.get_conn('consumer cycle closer:out1_condenser recirculation pump:in1').set_attr(T=self.cond_in_T)
self.LFE = self.heat_source_T - 5
self.nw.get_conn('condenser:out2_sink ambient:in1').set_attr(T=self.LFE)
self.nw.get_comp('consumer').set_attr(Q=-self.Q_Supplied)
try:
self.nw.solve('offdesign', design_path='heat_pump')
self.cond_m = self.nw.get_conn('condenser:out2_consumer:in1').m.val #TODO funktioniert es ? muss verändert werden !
self.cons_T = self.nw.get_conn('condenser:out2_consumer:in1').T.val
self.P_cons = self.nw.busses["Total power input"].P.val # TODO funktioniert berechnung der benötigten Leistung ?
self.COP = abs(self.Q_Supplied/self.P_cons) # TODO funktioniert berechnung des COP mit der Leistung und dem Stromverbrauch
except:
self.step_error()
def step_error(self):
self.skip_step = True
self.P_cons = 0
self.COP = 0
self.Q_Supplied = 0
self.cond_m = 0
self.cons_T = 0
self.Q_evap = 0
if __name__ == '__main__':
heat_pump_1 = Heat_Pump_Des()
t_am = 12.00 # Temperature of the heat source
inputs_air_1 = {'heat_source_T': t_am, 'Q_Demand': 6000, 'cond_in_T': 39.00, 'T_amb': t_am}
heat_pump_1.step(inputs_air_1)
print('P : ', heat_pump_1.P_cons)
print('Q_supplied : ',heat_pump_1.Q_Supplied)
print('COP : ', heat_pump_1.COP)
print('cond_m :', heat_pump_1.cond_m)
print('const_t: ',heat_pump_1.cons_T)
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4 replies
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Hi Simon, I did not have enough time to look into this in detail. One quick note: The Best Francesco |
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Thanks for your help. This helped me. I still have a small error which is the pump at the pump (apu). It has negative values for the consumed power. But the rest of the values make sense. If you have short amount of time to talk about the cooling heatpump it would be great. Best |
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you could join the next online user meeting, Monday 17:00 CET. Best |
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Thanks for the info. Trying to join |
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Dear community.
I am trying to use a heat pump for the purpose of cooling a bus.
The heat pump should be designed for a maximum cooling capacity of 25.000 W.
I changed the design of https://gitlab.com/mosaik/components/energy/mosaik-heatpump/-/tree/master?ref_type=heads.
I change the condenser from type condenser to type heat exchanger so the heat can be dumped to the ambient.
The temperature of the air dumped to the ambient is 5 °C lower than the ambient temperature.
The evaporator is getting the heat from the consumer, which is a heat source in our case.
Due to the change from condenser type to heat exchanger type, I get the error that I did not provide enough parameters.
Can you please help me to understand what I am missing here?
The sketch as well as the code are added.
Best wishes Simon
heatpump_cooling.zip
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