Skip to content

Commit

Permalink
Enforce DOE defn's.
Browse files Browse the repository at this point in the history
  • Loading branch information
Phil Ahrenkiel authored and Phil Ahrenkiel committed Jan 6, 2024
1 parent 900107a commit bff4b12
Show file tree
Hide file tree
Showing 3 changed files with 217 additions and 92 deletions.
254 changes: 185 additions & 69 deletions src/HPWH.cc
View file
Original file line number Diff line number Diff line change
Expand Up @@ -2904,20 +2904,21 @@ double HPWH::getStandbyLosses(UNITS units /*=UNITS_KWH*/) const
}
}

double HPWH::getTankHeatContent_kJ() const
double HPWH::getTankTemp_C() const
{
// returns tank heat content relative to 0 C using kJ

// get average tank temperature
double avgTemp = 0.0;
for (int i = 0; i < getNumNodes(); i++)
double totalT_C = 0.;
for (auto& T_C : tankTemps_C)
{
avgTemp += tankTemps_C[i];
totalT_C += T_C;
}
avgTemp /= getNumNodes();
return totalT_C / static_cast<double>(getNumNodes());
}

double totalHeat = avgTemp * DENSITYWATER_kgperL * CPWATER_kJperkgC * tankVolume_L;
return totalHeat;
double HPWH::getTankHeatContent_kJ() const
{
// returns tank heat content relative to 0 C using kJ
return DENSITYWATER_kgperL * tankVolume_L * CPWATER_kJperkgC * getTankTemp_C();
}

double HPWH::getLocationTemp_C() const { return locationTemperature_C; }
Expand Down Expand Up @@ -5432,7 +5433,7 @@ HPWH::Usage HPWH::findUsageFromMaximumGPM_Rating()
/// @param[out] UEF Result of calculation
/// @return true (success), false (failure).
//-----------------------------------------------------------------------------
bool HPWH::runDailyTest(const Usage usage, DailyTestSummary &dailyTestSummary)
bool HPWH::runDailyTest(const Usage usage, DailyTestSummary& dailyTestSummary)
{
// select the draw pattern based on usage
DrawPattern* drawPattern = nullptr;
Expand Down Expand Up @@ -5464,14 +5465,11 @@ bool HPWH::runDailyTest(const Usage usage, DailyTestSummary &dailyTestSummary)
return false;
}

const double inletT_C = 14.4; // p. 40433
const double ambientT_C = 19.7; // p. 40435
const double inletT_C = 14.4; // p. 40433
const double ambientT_C = 19.7; // p. 40435
const double externalT_C = 19.7;
const DRMODES drMode = DR_ALLOW;

double dailyRemovedVolume_L = 0.;
double dailyUsedEnergy_kJ = 0.;

/*
constexpr double setpointT_C = 51.7; //
if (!isSetpointFixed())
Expand All @@ -5483,22 +5481,61 @@ bool HPWH::runDailyTest(const Usage usage, DailyTestSummary &dailyTestSummary)
}
*/

// first-recovery info
bool isFirstRecoveryPeriod = true;
int preTime_min = 0;
bool heatersAreOn = false;
// 1-hr initiation
while ((preTime_min < 60) || heatersAreOn)
{
if (runOneStep(inletT_C, // inlet water temperature (C)
0, // draw volume (L)
ambientT_C, // ambient Temp (C)
externalT_C, // external Temp (C)
drMode, // DDR Status
0., // inlet-2 volume (L)
inletT_C, // inlet-2 Temp (C)
NULL) // no extra heat
== HPWH_ABORT)
{
return false;
}

double dailyHeatingEnergy_kJ = 0.; // total energy added to water over 24-hr test
heatersAreOn = false;
for (auto& heatSource : heatSources)
{
heatersAreOn |= heatSource.isEngaged();
}

// std::cout << preTime_min << ": " << getTankTemp_C() << ", " << (heatersAreOn? "On":
// "Off") << "\n";

++preTime_min;
}

double tankT_C = getTankTemp_C();
double initialTankT_C = tankT_C;

double dailyRemovedVolume_L = 0.;
double dailyUsedEnergy_kJ = 0.;
double dailyHeatingEnergy_kJ = 0.; // total energy added to water over 24-hr test
double dailyUsedElectricalEnergy_kJ = 0.; // total electrical energy consumed over 24-hr test
double dailyUsedFossilFuelEnergy_kJ = 0.; // total "fossil-fuel" energy consumed over 24-hr test

// first-recovery info
bool isFirstRecoveryPeriod = true;
double firstRecoveryUsedEnergy_kJ = 0.;
double recoveryHeatingEnergy_kJ = 0.;

int runTime_min = 0;
for (auto& draw : *drawPattern)
{
double drawnVolume_L = 0.;
double drawVolume_L = 0.;
double drawVolumeTemperature_LC = 0.;
double drawHeatingEnergy_kJ = 0.;
double drawUsedElectricalEnergy_kJ = 0.;
double drawUsedFossilFuelEnergy_kJ = 0.;

double recoveryVolume_L = 0.;
double recoveryVolumeTemperature_LC = 0.;
double recoveryUsedElectricalEnergy_kJ = 0.;
double recoveryUsedFossilFuelEnergy_kJ = 0.;
double drawSumOutletVolumeT_LC = 0.;
double drawSumInletVolumeT_LC = 0.;
int drawSumTimeT_minC = 0;

// limit draw-volume increment to tank volume
double incrementalDrawVolume_L = draw.flowRate_Lper_min * (1.);
Expand All @@ -5507,13 +5544,16 @@ bool HPWH::runDailyTest(const Usage usage, DailyTestSummary &dailyTestSummary)
incrementalDrawVolume_L = tankVolume_L;
}

bool includedInFirstRecoveryPeriod = isFirstRecoveryPeriod;
bool isDrawComplete = false;
// iterate until 1) specified draw volume has been reached and 2) next draw has started
while ((drawnVolume_L < draw.volume_L) || (runTime_min < draw.startTime_min))
while ((drawVolume_L < draw.volume_L) || (runTime_min < draw.startTime_min))
{
// do not exceed specified draw volume
if (drawnVolume_L + incrementalDrawVolume_L > draw.volume_L)
if (drawVolume_L + incrementalDrawVolume_L > draw.volume_L)
{
incrementalDrawVolume_L = draw.volume_L - drawnVolume_L;
incrementalDrawVolume_L = draw.volume_L - drawVolume_L;
isDrawComplete = true;
}

// run a step
Expand All @@ -5531,85 +5571,161 @@ bool HPWH::runDailyTest(const Usage usage, DailyTestSummary &dailyTestSummary)
return false;
}

// collect consumed electrical-energy info
tankT_C = getTankTemp_C();

drawSumOutletVolumeT_LC += incrementalDrawVolume_L * outletTemp_C;
drawSumInletVolumeT_LC += incrementalDrawVolume_L * inletT_C;
++drawSumTimeT_minC;

// collect heating energy
double incrementalDrawMass_kg = DENSITYWATER_kgperL * incrementalDrawVolume_L;
double incrementalDrawHeatCapacity_kJperC = CPWATER_kJperkgC * incrementalDrawMass_kg;
drawHeatingEnergy_kJ += incrementalDrawHeatCapacity_kJperC * (outletTemp_C - inletT_C);

// collect used-energy info
double usedFossilFuelEnergy_kJ = 0.;
double usedElectricalEnergy_kJ = 0.;
for (int iHS = 0; iHS < getNumHeatSources(); ++iHS)
{
usedElectricalEnergy_kJ += getNthHeatSourceEnergyInput(iHS, HPWH::UNITS_KJ);
}
drawUsedFossilFuelEnergy_kJ += usedFossilFuelEnergy_kJ;
drawUsedElectricalEnergy_kJ += usedElectricalEnergy_kJ;

// collect recovery info
recoveryVolume_L += incrementalDrawVolume_L;
recoveryVolumeTemperature_LC += incrementalDrawVolume_L * outletTemp_C;
recoveryUsedElectricalEnergy_kJ += usedElectricalEnergy_kJ;
recoveryUsedFossilFuelEnergy_kJ += usedFossilFuelEnergy_kJ;
if (isFirstRecoveryPeriod)
{
firstRecoveryUsedEnergy_kJ += usedFossilFuelEnergy_kJ + usedElectricalEnergy_kJ;
if (isDrawComplete) // check for cut-off
{
heatersAreOn = false;
for (auto& heatSource : heatSources)
{
heatersAreOn |= heatSource.isEngaged();
}
if (!heatersAreOn)
{
isFirstRecoveryPeriod = false;

drawnVolume_L += incrementalDrawVolume_L;
double tankContentMass_kg = DENSITYWATER_kgperL * tankVolume_L;
double tankHeatCapacity_kJperC = CPWATER_kJperkgC * tankContentMass_kg;
recoveryHeatingEnergy_kJ +=
tankHeatCapacity_kJperC * (tankT_C - initialTankT_C);
}
}
}

drawVolume_L += incrementalDrawVolume_L;
++runTime_min;
}

// collect end-of-draw info
double recoveryUsedEnergy_kJ = recoveryUsedElectricalEnergy_kJ + recoveryUsedFossilFuelEnergy_kJ; // see 6.4.3

double recoveryOutletT_C = 0.;
if (recoveryVolume_L > 0.)
if (includedInFirstRecoveryPeriod)
{
recoveryOutletT_C = recoveryVolumeTemperature_LC / recoveryVolume_L;
}
double recoveryMassRemoved_kg = HPWH::DENSITYWATER_kgperL * drawnVolume_L;
double recoveryHeatCapacity_kJperC = HPWH::CPWATER_kJperkgC * recoveryMassRemoved_kg;
double recoveryHeatingEnergy_kJ = recoveryHeatCapacity_kJperC * (recoveryOutletT_C - inletT_C);
double meanDrawOutletT_C = drawSumOutletVolumeT_LC / drawVolume_L;
double meanDrawInletT_C = drawSumInletVolumeT_LC / drawVolume_L;

if (isFirstRecoveryPeriod)
{
// find the "Recovery Efficiency" (6.4.2)
if (recoveryUsedEnergy_kJ > 0.)
{
dailyTestSummary.recoveryEfficiency = recoveryHeatingEnergy_kJ / recoveryUsedEnergy_kJ;
}
isFirstRecoveryPeriod = false;
}
double drawMass_kg = DENSITYWATER_kgperL * drawVolume_L;
double drawHeatCapacity_kJperC = CPWATER_kJperkgC * drawMass_kg;

dailyHeatingEnergy_kJ += recoveryHeatingEnergy_kJ;
recoveryHeatingEnergy_kJ +=
drawHeatCapacity_kJperC * (meanDrawOutletT_C - meanDrawInletT_C);
}

// collect 24-hr test info
dailyRemovedVolume_L += drawnVolume_L;
dailyUsedElectricalEnergy_kJ += recoveryUsedElectricalEnergy_kJ;
dailyUsedFossilFuelEnergy_kJ += recoveryUsedFossilFuelEnergy_kJ;
dailyUsedEnergy_kJ += recoveryUsedEnergy_kJ;
dailyRemovedVolume_L += drawVolume_L;
dailyHeatingEnergy_kJ += drawHeatingEnergy_kJ;
dailyUsedElectricalEnergy_kJ += drawUsedElectricalEnergy_kJ;
dailyUsedEnergy_kJ += drawUsedFossilFuelEnergy_kJ + drawUsedElectricalEnergy_kJ;
}

// find the "Adjusted Daily Water Heating Energy Consumption" (6.3.6)
dailyTestSummary.adjustedDailyWaterHeatingEnergy_kJ = 0.;
if (dailyTestSummary.recoveryEfficiency > 0.)
// find the "Recovery Efficiency" (6.3.3)
dailyTestSummary.recoveryEfficiency = 0.;
if (firstRecoveryUsedEnergy_kJ > 0.)
{
dailyTestSummary.adjustedDailyWaterHeatingEnergy_kJ = dailyHeatingEnergy_kJ / dailyTestSummary.recoveryEfficiency;
dailyTestSummary.recoveryEfficiency = recoveryHeatingEnergy_kJ / firstRecoveryUsedEnergy_kJ;
}

// find the "Uniform Energy Factor" (6.4.4)
const double standardSetpointT_C = 51.7; //
const double standardInletT_C = 14.4; //

// find the standard daily heating energy
constexpr double standardSetpointT_C = 51.7;
constexpr double standardInletT_C = 14.4;
double dailyMassRemoved_kg = HPWH::DENSITYWATER_kgperL * dailyRemovedVolume_L;
double dailyHeatCapacity_kJperC = HPWH::CPWATER_kJperkgC * dailyMassRemoved_kg;
double standardDailyHeatingEnergy_kJ = dailyHeatCapacity_kJperC * (standardSetpointT_C - standardInletT_C);
dailyTestSummary.UEF = standardDailyHeatingEnergy_kJ / dailyUsedEnergy_kJ;
double standardDailyHeatingEnergy_kJ =
dailyHeatCapacity_kJperC * (standardSetpointT_C - standardInletT_C);

// find the "Daily Water Heating Energy Consumption (Qd)" (6.3.5)
dailyTestSummary.dailyHeatingEnergyConsumption_kJ = dailyUsedEnergy_kJ;
if (dailyTestSummary.recoveryEfficiency > 0.)
{
double tankContentMass_kg = DENSITYWATER_kgperL * tankVolume_L;
double tankHeatCapacity_kJperC = CPWATER_kJperkgC * tankContentMass_kg;
dailyTestSummary.dailyHeatingEnergyConsumption_kJ += tankHeatCapacity_kJperC *
(tankT_C - initialTankT_C) /
dailyTestSummary.recoveryEfficiency;
}

// find the "Adjusted Daily Water Heating Energy Consumption (Qda)" (6.3.6a)
// same as above, because no change in ambient temperature
dailyTestSummary.adjustedDailyWaterHeatingEnergyConsumption_kJ =
dailyTestSummary.dailyHeatingEnergyConsumption_kJ;

// find the "Energy Used to Heat Water (Q_HW)" (6.3.6a)
dailyTestSummary.energyUsedToHeatWater_kJ = 0.;
if (dailyTestSummary.recoveryEfficiency > 0.)
{
dailyTestSummary.energyUsedToHeatWater_kJ =
dailyHeatingEnergy_kJ / dailyTestSummary.recoveryEfficiency;
}

// find the "Standard Energy Used to Heat Water (Q_HW,T)" (6.3.6b)
dailyTestSummary.standardEnergyUsedToHeatWater_kJ = 0.;
if (dailyTestSummary.recoveryEfficiency > 0.)
{
double removedMass_kg = DENSITYWATER_kgperL * dailyRemovedVolume_L;
double removedHeatCapacity_kJperC = CPWATER_kJperkgC * removedMass_kg;
double standardRemovedEnergy_kJ =
removedHeatCapacity_kJperC * (standardSetpointT_C - standardInletT_C);
dailyTestSummary.standardEnergyUsedToHeatWater_kJ =
standardRemovedEnergy_kJ / dailyTestSummary.recoveryEfficiency;
}

// add to the adjusted daily water heating energy consumption (p. 40487)
double energyUsedToHeatWaterDifference_kJ = dailyTestSummary.standardEnergyUsedToHeatWater_kJ -
dailyTestSummary.energyUsedToHeatWater_kJ;
dailyTestSummary.adjustedDailyWaterHeatingEnergyConsumption_kJ +=
energyUsedToHeatWaterDifference_kJ;

// find the "Modified Daily Water Heating Energy Consumption (Qdm = Qda - QHWD) (p. 40487)
// note: same as Q_HW,T
dailyTestSummary.modifiedDailyWaterHeatingEnergyConsumption_kJ =
dailyTestSummary.adjustedDailyWaterHeatingEnergyConsumption_kJ -
energyUsedToHeatWaterDifference_kJ;

// find the "Uniform Energy Factor" (6.4.4)
dailyTestSummary.UEF = 0.;
if (dailyTestSummary.modifiedDailyWaterHeatingEnergyConsumption_kJ > 0.)
{
dailyTestSummary.UEF = standardDailyHeatingEnergy_kJ /
dailyTestSummary.modifiedDailyWaterHeatingEnergyConsumption_kJ;
}

// find the "Annual Energy Consumption" (6.4.5)
dailyTestSummary.annualEnergyConsumption_kJ = 0.;
if (dailyTestSummary.UEF > 0.)
{
constexpr double days_per_year = 365.;
const double nominalDifferenceT_C = F_TO_C(67.);
dailyTestSummary.annualEnergyConsumption_kJ = days_per_year * dailyHeatCapacity_kJperC * nominalDifferenceT_C / dailyTestSummary.UEF;
dailyTestSummary.annualEnergyConsumption_kJ =
days_per_year * dailyHeatCapacity_kJperC * nominalDifferenceT_C / dailyTestSummary.UEF;
}

// find the "Annual Electrical Energy Consumption" (6.4.6)
dailyTestSummary.annualElectricalEnergyConsumption_kJ = 0.;
if (dailyUsedEnergy_kJ > 0.)
{
dailyTestSummary.annualElectricalEnergyConsumption_kJ = (dailyUsedElectricalEnergy_kJ / dailyUsedEnergy_kJ) * dailyTestSummary.annualEnergyConsumption_kJ;
dailyTestSummary.annualElectricalEnergyConsumption_kJ =
(dailyUsedElectricalEnergy_kJ / dailyUsedEnergy_kJ) *
dailyTestSummary.annualEnergyConsumption_kJ;
}

return true;
Expand Down
13 changes: 10 additions & 3 deletions src/HPWH.hh
View file
Original file line number Diff line number Diff line change
Expand Up @@ -898,6 +898,9 @@ class HPWH
void resetTopOffTimer();
/**< resets variables for timer associated with the DR_TOT call */

/// returns the average tank temperature
double getTankTemp_C() const;

double getLocationTemp_C() const;
int setMaxTempDepression(double maxDepression, UNITS units = UNITS_C);

Expand Down Expand Up @@ -959,17 +962,21 @@ class HPWH
/// Determine usage using the maximum GPM rating method
Usage findUsageFromMaximumGPM_Rating();

struct DailyTestSummary
struct DailyTestSummary
{
double UEF;
double recoveryEfficiency;
double adjustedDailyWaterHeatingEnergy_kJ;
double dailyHeatingEnergyConsumption_kJ;
double adjustedDailyWaterHeatingEnergyConsumption_kJ;
double modifiedDailyWaterHeatingEnergyConsumption_kJ;
double energyUsedToHeatWater_kJ;
double standardEnergyUsedToHeatWater_kJ;
double annualElectricalEnergyConsumption_kJ;
double annualEnergyConsumption_kJ;
};

/// run 24-hr draw pattern
bool runDailyTest(const Usage usage, DailyTestSummary &dailyTestSummary);
bool runDailyTest(const Usage usage, DailyTestSummary& dailyTestSummary);

struct Draw
{
Expand Down
Loading

0 comments on commit bff4b12

Please sign in to comment.