From 3c62414c18c22a314863d271513a8f8550840d66 Mon Sep 17 00:00:00 2001 From: Yujie Xu Date: Tue, 24 Sep 2024 16:19:01 -0700 Subject: [PATCH] Fix min pressure lower bound Pdischarge is the compressor discharge pressure, this->CompMaxDeltaP is the maximum compressor pressure rise Pdischarge - this->CompMaxDeltaP is minimum compressor suction pressure RefMinPe is minimum refrigerant evaporating pressure These two terms are both lower bounds of the suction pressure CapMinPe should be no less than both of them, so CapMinPe should be max of the two LB, not min --- src/EnergyPlus/HVACVariableRefrigerantFlow.cc | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/src/EnergyPlus/HVACVariableRefrigerantFlow.cc b/src/EnergyPlus/HVACVariableRefrigerantFlow.cc index 06a42986f2a..2f415a8da54 100644 --- a/src/EnergyPlus/HVACVariableRefrigerantFlow.cc +++ b/src/EnergyPlus/HVACVariableRefrigerantFlow.cc @@ -11591,7 +11591,8 @@ void VRFCondenserEquipment::CalcVRFCondenser_FluidTCtrl(EnergyPlusData &state, c Tdischarge = this->refrig->getSatTemperature(state, max(min(Pdischarge, RefPHigh), RefPLow), RoutineName); // Evaporative capacity ranges_Min - CapMinPe = min(Pdischarge - this->CompMaxDeltaP, RefMinPe); + // suction pressure lower bound need to be no less than both terms in the following + CapMinPe = max(Pdischarge - this->CompMaxDeltaP, RefMinPe); CapMinTe = this->refrig->getSatTemperature(state, max(min(CapMinPe, RefPHigh), RefPLow), RoutineName); CompEvaporatingCAPSpdMin = this->CoffEvapCap * this->RatedEvapCapacity * CurveValue(state, this->OUCoolingCAPFT(1), Tdischarge, CapMinTe); CompEvaporatingPWRSpdMin = this->RatedCompPower * CurveValue(state, this->OUCoolingPWRFT(1), Tdischarge, CapMinTe); @@ -11663,8 +11664,7 @@ void VRFCondenserEquipment::CalcVRFCondenser_FluidTCtrl(EnergyPlusData &state, c Tdischarge, h_IU_cond_out_ave, this->IUCondensingTemp, - // Te can't be smaller than user input lower bound - max(this->IUEvapTempLow, CapMinTe), + CapMinTe, Tfs, Pipe_Q_h, Q_c_OU,