# -*- coding: utf-8 -*- import numpy as np from tespy.components import ( Compressor, CycleCloser, HeatExchanger, Motor, MovingBoundaryHeatExchanger, PowerBus, PowerSource, Pump, Sink, Source, Valve ) from tespy.connections import Connection, PowerConnection, Ref from tespy.models import ModelTemplate from tespy.networks import Network from tespy.tools.characteristics import CharLine, load_default_char as ldc class HeatPumpModel(ModelTemplate): """Ground-source heat pump with geothermal collector and heating system. Parameters ---------- fluid : str Working fluid for the refrigerant cycle, e.g. "NH3" or "R410A". Tamb : float Ambient (reference) temperature in °C. pamb : float Ambient (reference) pressure in bar. Tgeo : float Mean geothermal temperature in °C. T_hs_feed : float Heating system feed flow temperature in °C. T_hs_ret : float Heating system return flow temperature in °C. """ def __init__( self, fluid, Tamb=2.8, pamb=1.013, Tgeo=9.5, T_hs_feed=40 ): self.fluid = fluid self.Tamb = Tamb self.pamb = pamb self.Tgeo = Tgeo self.T_hs_feed = T_hs_feed self._ean = None super().__init__() # ------------------------------------------------------------------ # ModelTemplate interface # ------------------------------------------------------------------ def _parameter_lookup(self): return { "T_geo": {"get": self._get_T_geo, "set": self._set_T_geo}, "T_hs": ["Connections", "c23", "T"], "Q": ["Components", "condenser", "Q"], "COP": {"get": self._calc_cop}, "epsilon": {"get": self._get_epsilon}, } def _create_network(self): self.nw = Network() self.nw.units.set_defaults( temperature="degC", pressure="bar", enthalpy="kJ/kg", pressure_difference="bar" ) # components cc = CycleCloser("cycle closer") cd = MovingBoundaryHeatExchanger("condenser") va = Valve("valve") ev = HeatExchanger("evaporator") cp = Compressor("compressor") gh_in = Source("ground heat feed flow") gh_out = Sink("ground heat return flow") ghp = Pump("ground heat loop pump") hs_feed = Sink("heating system feed flow") hs_ret = Source("heating system return flow") hsp = Pump("heating system pump") # refrigerant cycle c1 = Connection(cc, "out1", cd, "in1", label="c1") c2 = Connection(cd, "out1", va, "in1", label="c2") c3 = Connection(va, "out1", ev, "in2", label="c3") c4 = Connection(ev, "out2", cp, "in1", label="c4") c5 = Connection(cp, "out1", cc, "in1", label="c5") self.nw.add_conns(c1, c2, c3, c4, c5) # geothermal circuit (boundary labels used in exergy analysis) c11 = Connection(gh_in, "out1", ghp, "in1", label="c11") c12 = Connection(ghp, "out1", ev, "in1", label="c12") c13 = Connection(ev, "out1", gh_out, "in1", label="c13") self.nw.add_conns(c11, c12, c13) # heating circuit (boundary labels used in exergy analysis) c21 = Connection(hs_ret, "out1", hsp, "in1", label="c21") c22 = Connection(hsp, "out1", cd, "in2", label="c22") c23 = Connection(cd, "out2", hs_feed, "in1", label="c23") self.nw.add_conns(c21, c22, c23) # component parametrization cd.set_attr( pr1=0.99, pr2=0.99, Q=-4e3, design=["pr2", "td_pinch"], offdesign=["zeta2", "UA_char"], ) kA_char1 = ldc("HeatExchanger", "kA_char1", "DEFAULT", CharLine) kA_char2 = ldc("HeatExchanger", "kA_char2", "EVAPORATING FLUID", CharLine) ev.set_attr( pr1=0.99, pr2=0.99, kA_char1=kA_char1, kA_char2=kA_char2, design=["pr1", "ttd_l"], offdesign=["zeta1", "kA_char"], ) cp.set_attr(eta_s=0.8, design=["eta_s"], offdesign=["eta_s_char"]) hsp.set_attr(eta_s=0.75, design=["eta_s"], offdesign=["eta_s_char"]) ghp.set_attr(eta_s=0.75, design=["eta_s"], offdesign=["eta_s_char"]) # connection parametrization c1.set_attr(fluid={self.fluid: 1}) c2.set_attr(x=0, T_bubble=40) c4.set_attr(td_dew=3, T_dew=5) c11.set_attr(T=self.Tgeo + 1.5, p=1.5, fluid={"water": 1}) c13.set_attr(T=Ref(c11, 1, -3), p=1.5) c21.set_attr(T=Ref(c23, 1, -5), p=2, fluid={"water": 1}) c23.set_attr(T=self.T_hs_feed, p=2) self.nw.solve("design") c2.set_attr(T_bubble=None) c4.set_attr(T_dew=None) cd.set_attr(td_pinch=5) ev.set_attr(ttd_l=5) # motor + power distribution mot_cp = Motor("motor compressor") mot_ghp = Motor("motor ground heat pump") mot_hsp = Motor("motor heating system pump") x = np.array([0, 0.2, 0.4, 0.6, 0.8, 1, 1.2]) y = np.array([0.2, 0.86, 0.9, 0.93, 0.95, 0.96, 0.95]) / 0.96 char = CharLine(x=x, y=y) mot_cp.set_attr(eta=0.96, eta_char=char, design=["eta"], offdesign=["eta_char"]) mot_ghp.set_attr(eta=0.96, eta_char=char, design=["eta"], offdesign=["eta_char"]) mot_hsp.set_attr(eta=0.96, eta_char=char, design=["eta"], offdesign=["eta_char"]) grid = PowerSource("grid") power_dist = PowerBus("power distribution", num_in=1, num_out=3) e1 = PowerConnection(grid, "power", power_dist, "power_in1", label="e1") e2 = PowerConnection(power_dist, "power_out1", mot_cp, "power_in", label="e2") e3 = PowerConnection(mot_cp, "power_out", cp, "power", label="e3") e4 = PowerConnection(power_dist, "power_out2", mot_ghp, "power_in", label="e4") e5 = PowerConnection(mot_ghp, "power_out", ghp, "power", label="e5") e6 = PowerConnection(power_dist, "power_out3", mot_hsp, "power_in", label="e6") e7 = PowerConnection(mot_hsp, "power_out", hsp, "power", label="e7") self.nw.add_conns(e1, e2, e3, e4, e5, e6, e7) self.nw.solve("design") def _set_T_geo(self, value): self.nw.get_conn("c11").set_attr(T=value - 1) def _get_T_geo(self): return self.nw.get_conn("c11").T.val + 1 def _calc_cop(self): cd = self.nw.get_comp("condenser") return abs(cd.Q.val_SI) / self.nw.get_conn("e1").E.val_SI def _get_epsilon(self): return None if self._ean is None else self._ean.epsilon