Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Add tolerance for high humidity OA control #7647

Merged
merged 1 commit into from
Dec 10, 2019
Merged

Add tolerance for high humidity OA control #7647

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
1 change: 1 addition & 0 deletions src/EnergyPlus/DataHVACGlobals.hh
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -75,6 +75,7 @@ namespace DataHVACGlobals {

// MODULE PARAMETER DEFINITIONS:

Real64 const SmallHumRatDiff(1.0E-7);
Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Using new approach for global constants - just declare it right in the header. Better for compiler optimization instead of using extern. Tempted to change all of these here, but don't want to muddy the waters.

extern Real64 const SmallTempDiff;
extern Real64 const SmallMassFlow;
extern Real64 const VerySmallMassFlow;
Expand Down
3 changes: 2 additions & 1 deletion src/EnergyPlus/MixedAir.cc
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -4593,7 +4593,8 @@ namespace MixedAir {
if (ZoneSysMoistureDemand(this->HumidistatZoneNum).TotalOutputRequired < 0.0) {
// IF OAController is not allowed to modify air flow during high outdoor humrat condition, then disable modified air flow
// if indoor humrat is less than or equal to outdoor humrat
if (!this->ModifyDuringHighOAMoisture && Node(this->NodeNumofHumidistatZone).HumRat <= this->OAHumRat) {
if (!this->ModifyDuringHighOAMoisture &&
(Node(this->NodeNumofHumidistatZone).HumRat - this->OAHumRat) <= DataHVACGlobals::SmallHumRatDiff) {
Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Require delta humrat to be > SmallHumRatDiff to activate high humidity flow rate.

HighHumidityOperationFlag = false;
} else {
HighHumidityOperationFlag = true;
Expand Down
171 changes: 171 additions & 0 deletions tst/EnergyPlus/unit/MixedAir.unit.cc
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1522,6 +1522,177 @@ TEST_F(EnergyPlusFixture, MixedAir_MissingHIghRHControlInputTest)
EXPECT_TRUE(compare_err_stream(error_string, true));
}

TEST_F(EnergyPlusFixture, MixedAir_HIghRHControlTest)
{
std::string const idf_objects = delimited_string({
" OutdoorAir:Node,",
" Outside Air Inlet Node 1; !- Name",

" Schedule:Constant,",
" Min OA Sched, !- Name",
" Any Number, !- Schedule Type Limits Name",
" 0.5; !- Value",

" ScheduleTypeLimits,",
" Any Number; !- Name",

" Controller:OutdoorAir,",
" OA Controller 1, !- Name",
" Relief Air Outlet Node 1, !- Relief Air Outlet Node Name",
" VAV Sys 1 Inlet Node, !- Return Air Node Name",
" Mixed Air Node 1, !- Mixed Air Node Name",
" Outside Air Inlet Node 1, !- Actuator Node Name",
" 0.0, !- Minimum Outdoor Air Flow Rate {m3/s}",
" 2.5, !- Maximum Outdoor Air Flow Rate {m3/s}",
" DifferentialDryBulb, !- Economizer Control Type",
" ModulateFlow, !- Economizer Control Action Type",
" , !- Economizer Maximum Limit Dry-Bulb Temperature {C}",
" , !- Economizer Maximum Limit Enthalpy {J/kg}",
" , !- Economizer Maximum Limit Dewpoint Temperature {C}",
" , !- Electronic Enthalpy Limit Curve Name",
" , !- Economizer Minimum Limit Dry-Bulb Temperature {C}",
" NoLockout, !- Lockout Type",
" ProportionalMinimum, !- Minimum Limit Type",
" Min OA Sched, !- Minimum Outdoor Air Schedule Name",
" , !- Minimum Fraction of Outdoor Air Schedule Name",
" , !- Maximum Fraction of Outdoor Air Schedule Name",
" , !- Mechanical Ventilation Controller Name",
" , !- Time of Day Economizer Control Schedule Name",
" Yes, !- High Humidity Control",
" Zone1, !- Humidistat Control Zone Name",
" 0.8, !- High Humidity Outdoor Air Flow Ratio",
" Yes; !- Control High Indoor Humidity Based on Outdoor Humidity Ratio",
});

ASSERT_TRUE(process_idf(idf_objects));

compare_err_stream(""); // just for debugging

bool ErrorsFound(false); // If errors detected in input
int ControllerNum(0); // Controller number
int NumArg(0);
int NumNums(0);
int NumAlphas(0);
int IOStat(0);
std::string const CurrentModuleObject = CurrentModuleObjects(CMO_OAController);

inputProcessor->getObjectDefMaxArgs(CurrentModuleObjects(CMO_OAController), NumArg, NumAlphas, NumNums);

Array1D<Real64> NumArray(NumNums, 0.0);
Array1D_string AlphArray(NumAlphas);
Array1D_string cAlphaFields(NumAlphas);
Array1D_string cNumericFields(NumNums);
Array1D_bool lAlphaBlanks(NumAlphas, true);
Array1D_bool lNumericBlanks(NumNums, true);

NumOAControllers = inputProcessor->getNumObjectsFound(CurrentModuleObject);
OAController.allocate(NumOAControllers);

ControllerNum = 1;
Zone.allocate(1);
Zone(1).Name = "ZONE1";
NumOfZones = 1;
ZoneEquipConfig.allocate(1);
ZoneEquipConfig(1).ActualZoneNum = 1;
ZoneEquipConfig(1).ZoneNode = 2;
ZoneEquipConfig(1).NumInletNodes = 1;
ZoneEquipConfig(1).InletNodeAirLoopNum.allocate(1);
ZoneEquipConfig(1).InletNodeAirLoopNum(1) = 1;
PrimaryAirSystem.allocate(1);
AirLoopControlInfo.allocate(1);
PrimaryAirSystem(1).NumBranches = 1;
PrimaryAirSystem(1).Branch.allocate(1);
PrimaryAirSystem(1).Branch(1).Comp.allocate(1);
PrimaryAirSystem(1).Branch(1).TotalComponents = 1;
PrimaryAirSystem(1).Branch(1).Comp(1).Name = "OASysName";
PrimaryAirSystem(1).Branch(1).Comp(1).TypeOf = "AirLoopHVAC:OutdoorAirSystem";
OutsideAirSys.allocate(1);
OutsideAirSys(1).Name = "OASysName";
OutsideAirSys(1).NumControllers = 1;
OutsideAirSys(1).ControllerType.allocate(1);
OutsideAirSys(1).ControllerType(1) = "Controller:OutdoorAir";
OutsideAirSys(1).ControllerName.allocate(1);
OutsideAirSys(1).ControllerName(1) = "OA Controller 1";
DataAirLoop::NumOASystems = 1;
HumidityControlZone.allocate(1);
HumidityControlZone(1).ActualZoneNum = 1;
NumHumidityControlZones = 1;

inputProcessor->getObjectItem(CurrentModuleObject,
ControllerNum,
AlphArray,
NumAlphas,
NumArray,
NumNums,
IOStat,
lNumericBlanks,
lAlphaBlanks,
cAlphaFields,
cNumericFields);

ProcessOAControllerInputs(CurrentModuleObject,
ControllerNum,
AlphArray,
NumAlphas,
NumArray,
NumNums,
lNumericBlanks,
lAlphaBlanks,
cAlphaFields,
cNumericFields,
ErrorsFound);
// compare_err_stream( "" ); // just for debugging

EXPECT_FALSE(ErrorsFound);
EXPECT_FALSE(OAController(ControllerNum)
.ModifyDuringHighOAMoisture); // "Control High Indoor Humidity Based on Outdoor Humidity Ratio = Yes" sets this to false
EXPECT_FALSE(has_err_output(true));
EXPECT_EQ(OAController(ControllerNum).HumidistatZoneNum, 1);

// Set up conditions
DataZoneEnergyDemands::ZoneSysMoistureDemand.allocate(1);
DataZoneEnergyDemands::ZoneSysMoistureDemand(1).TotalOutputRequired = -1.0; // dehumidification requested by humidistat
EXPECT_EQ(OAController(ControllerNum).NodeNumofHumidistatZone, ZoneEquipConfig(1).ZoneNode);
int airLoopNum = 1;
int outAirMinFrac = 0.0;
Real64 OASignal = 0.0;
bool HighHumidityOperationFlag = false;
bool firstHVACIteration = false;
OAController(ControllerNum).MixSetTemp = 15.0;
OAController(ControllerNum).RetTemp = 20.0;
OAController(ControllerNum).InletTemp = 25.0;
OAController(ControllerNum).MixMassFlow = 2.5;
OAController(ControllerNum).MaxOAMassFlowRate = 2.5;

// Case 1 - OA humrat = zone humrat - no high humidity operation
Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

New unit test with 4 cases.

Node(ZoneEquipConfig(1).ZoneNode).HumRat = 0.006;
OAController(ControllerNum).OAHumRat = 0.006;
OAController(ControllerNum).CalcOAEconomizer(airLoopNum, outAirMinFrac, OASignal, HighHumidityOperationFlag, firstHVACIteration);
EXPECT_FALSE(OAController(ControllerNum).HighHumCtrlActive);
EXPECT_NEAR(OASignal, 0.0, 0.00001);

// Case 2 - OA humrat < zone humrat - high humidity operation
Node(ZoneEquipConfig(1).ZoneNode).HumRat = 0.006;
OAController(ControllerNum).OAHumRat = 0.006 - DataHVACGlobals::SmallHumRatDiff;
OAController(ControllerNum).CalcOAEconomizer(airLoopNum, outAirMinFrac, OASignal, HighHumidityOperationFlag, firstHVACIteration);
EXPECT_TRUE(OAController(ControllerNum).HighHumCtrlActive);
EXPECT_NEAR(OASignal, 0.8, 0.00001);

// Case 3 - OA humrat within tolerance of zone humrat - no high humidity operation
Node(ZoneEquipConfig(1).ZoneNode).HumRat = 0.006;
OAController(ControllerNum).OAHumRat = 0.006 - DataHVACGlobals::SmallHumRatDiff / 2.0;
OAController(ControllerNum).CalcOAEconomizer(airLoopNum, outAirMinFrac, OASignal, HighHumidityOperationFlag, firstHVACIteration);
EXPECT_FALSE(OAController(ControllerNum).HighHumCtrlActive);
EXPECT_NEAR(OASignal, 0.0, 0.00001);

// Case 4 - OA humrat slightly above zone humrat - no high humidity operation
Node(ZoneEquipConfig(1).ZoneNode).HumRat = 0.006;
OAController(ControllerNum).OAHumRat = 0.006 + DataHVACGlobals::SmallHumRatDiff / 2.0;
OAController(ControllerNum).CalcOAEconomizer(airLoopNum, outAirMinFrac, OASignal, HighHumidityOperationFlag, firstHVACIteration);
EXPECT_FALSE(OAController(ControllerNum).HighHumCtrlActive);
EXPECT_NEAR(OASignal, 0.0, 0.00001);
}

TEST_F(EnergyPlusFixture, OAControllerMixedAirSPTest)
{

Expand Down