Heat exchange models

src/HPWH.cc

@@ -190,6 +190,8 @@ void HPWH::setAllDefaults() {
 	usesSoCLogic = false;
 	setMinutesPerStep(1.0);
 	hpwhVerbosity = VRB_minuteOut;
+	hasHeatExchanger = false;
+	heatExchangerEffectiveness = 0.9;
 }
 
 HPWH::HPWH(const HPWH &hpwh) {
@@ -2447,77 +2449,93 @@ void HPWH::updateTankTemps(double drawVolume_L,double inletT_C,double tankAmbien
 			lowInletT = inletT_C;
 			lowInletV = drawVolume_L - inletVol2_L;
 		}
-		//calculate how many nodes to draw (drawVolume_N)
-		double drawVolume_N = drawVolume_L / nodeVolume_L;
-		if(drawVolume_L > tankVolume_L) {
-			//if (hpwhVerbosity >= VRB_reluctant) {
-			//	//msg("WARNING: Drawing more than the tank volume in one step is undefined behavior.  Terminating simulation.  \n");
-			//	msg("WARNING: Drawing more than the tank volume in one step is undefined behavior.  Continuing simulation at your own risk.  \n");
-			//}
-			//simHasFailed = true;
-			//return;
-			for(int i = 0; i < getNumNodes(); i++){
-				outletTemp_C += tankTemps_C[i];
-				tankTemps_C[i] = (inletT_C * (drawVolume_L - inletVol2_L) + inletT2_C * inletVol2_L) / drawVolume_L;
-			}
-			outletTemp_C = (outletTemp_C / getNumNodes() * tankVolume_L + tankTemps_C[0] * (drawVolume_L - tankVolume_L))
-				/ drawVolume_L * drawVolume_N;
 
-			drawVolume_N = 0.;
+		if (hasHeatExchanger) {// heat-exchange models
+
+			const double densityTank_kgperL = DENSITYWATER_kgperL;
+			const double CpTank_kJperkgC  = CPWATER_kJperkgC;
+
+			double C_Node_kJperC = CpTank_kJperkgC * densityTank_kgperL * nodeVolume_L;
+			double C_draw_kJperC = CPWATER_kJperkgC * DENSITYWATER_kgperL * drawVolume_L;
+
+			outletTemp_C = inletT_C;
+			for (auto &nodeTemp: tankTemps_C) {	
+				double maxHeatExchange_kJ = (nodeTemp - outletTemp_C) / (1. / C_Node_kJperC + 1. / C_draw_kJperC);
+				double heatExchange_kJ = heatExchangerEffectiveness * maxHeatExchange_kJ;
+
+				nodeTemp -= heatExchange_kJ / C_Node_kJperC;
+				outletTemp_C += heatExchange_kJ / C_draw_kJperC;
+			}
 		}
+		else { 
+			//calculate how many nodes to draw (drawVolume_N)
+			double drawVolume_N = drawVolume_L / nodeVolume_L;
+			if(drawVolume_L > tankVolume_L) {
+				//if (hpwhVerbosity >= VRB_reluctant) {
+				//	//msg("WARNING: Drawing more than the tank volume in one step is undefined behavior.  Terminating simulation.  \n");
+				//	msg("WARNING: Drawing more than the tank volume in one step is undefined behavior.  Continuing simulation at your own risk.  \n");
+				//}
+				//simHasFailed = true;
+				//return;
+				for(int i = 0; i < getNumNodes(); i++){
+					outletTemp_C += tankTemps_C[i];
+					tankTemps_C[i] = (inletT_C * (drawVolume_L - inletVol2_L) + inletT2_C * inletVol2_L) / drawVolume_L;
+				}
+				outletTemp_C = (outletTemp_C / getNumNodes() * tankVolume_L + tankTemps_C[0] * (drawVolume_L - tankVolume_L))
+					/ drawVolume_L * drawVolume_N;
 
-		/////////////////////////////////////////////////////////////////////////////////////////////////
+				drawVolume_N = 0.;
+			}
+
+			while(drawVolume_N > 0) {
 
-		while(drawVolume_N > 0) {
+				// Draw one node at a time
+				double drawFraction = drawVolume_N > 1. ? 1. : drawVolume_N;
+				double nodeInletTV = 0.;
 
-			// Draw one node at a time
-			double drawFraction = drawVolume_N > 1. ? 1. : drawVolume_N;
-			double nodeInletTV = 0.;
+				//add temperature for outletT average
+				outletTemp_C += drawFraction * tankTemps_C[getNumNodes() - 1];
 
-			//add temperature for outletT average
-			outletTemp_C += drawFraction * tankTemps_C[getNumNodes() - 1];
+				double cumInletFraction = 0.;
+				for(int i = getNumNodes() - 1; i >= lowInletH; i--) {
 
-			double cumInletFraction = 0.;
-			for(int i = getNumNodes() - 1; i >= lowInletH; i--) {
 
 				// Reset inlet inputs at this node. 
 				double nodeInletFraction = 0.;
 				nodeInletTV = 0.;
 
 				// Sum of all inlets Vi*Ti at this node
 				if(i == highInletH) {
-					nodeInletTV += highInletV * drawFraction / drawVolume_L * highInletT;
-					nodeInletFraction += highInletV * drawFraction / drawVolume_L;
+				  nodeInletTV += highInletV * drawFraction / drawVolume_L * highInletT;
+				  nodeInletFraction += highInletV * drawFraction / drawVolume_L;
 				}
 				if(i == lowInletH) {
-					nodeInletTV += lowInletV * drawFraction / drawVolume_L * lowInletT;
-					nodeInletFraction += lowInletV * drawFraction / drawVolume_L;
+				  nodeInletTV += lowInletV * drawFraction / drawVolume_L * lowInletT;
+				  nodeInletFraction += lowInletV * drawFraction / drawVolume_L;
 
 					break; // if this is the bottom inlet break out of the four loop and use the boundary condition equation. 
 				}
 
-				// Look at the volume and temperature fluxes into this node
-				tankTemps_C[i] = (1. - (drawFraction - cumInletFraction)) * tankTemps_C[i] +
-					nodeInletTV +
-					(drawFraction - (cumInletFraction + nodeInletFraction)) * tankTemps_C[i - 1];
+					// Look at the volume and temperature fluxes into this node
+					tankTemps_C[i] = (1. - (drawFraction - cumInletFraction)) * tankTemps_C[i] +
+						nodeInletTV +
+						(drawFraction - (cumInletFraction + nodeInletFraction)) * tankTemps_C[i - 1];
 
-				cumInletFraction += nodeInletFraction;
-
-			}
+					cumInletFraction += nodeInletFraction;
 
-			// Boundary condition equation because it shouldn't take anything from tankTemps_C[i - 1] but it also might not exist. 
-			tankTemps_C[lowInletH] = (1. - (drawFraction - cumInletFraction)) * tankTemps_C[lowInletH] + nodeInletTV;
-
-			drawVolume_N -= drawFraction;
+				}
 
-			mixTankInversions();
-		}
+				// Boundary condition equation because it shouldn't take anything from tankTemps_C[i - 1] but it also might not exist. 
+				tankTemps_C[lowInletH] = (1. - (drawFraction - cumInletFraction)) * tankTemps_C[lowInletH] + nodeInletTV;
 
+				drawVolume_N -= drawFraction;
 
-		//fill in average outlet T - it is a weighted averaged, with weights == nodes drawn
-		this->outletTemp_C /= (drawVolume_L / nodeVolume_L);
+				mixTankInversions();
+			}
 
-		/////////////////////////////////////////////////////////////////////////////////////////////////
+			//fill in average outlet T - it is a weighted averaged, with weights == nodes drawn
+			outletTemp_C /= (drawVolume_L / nodeVolume_L);
+		}
 
 		//Account for mixing at the bottom of the tank
 		if(tankMixesOnDraw && drawVolume_L > 0.) {
@@ -2527,7 +2545,7 @@ void HPWH::updateTankTemps(double drawVolume_L,double inletT_C,double tankAmbien
 
 	} //end if(draw_volume_L > 0)
 
-
+	/////////////////////////////////////////////////////////////////////////////////////////////////
 	if(doConduction) {
 
 		// Get the "constant" tau for the stability condition and the conduction calculation
@@ -2896,7 +2914,6 @@ void HPWH::mapResRelativePosToHeatSources() {
 		});
 }
 
-
 // Used to check a few inputs after the initialization of a tank model from a preset or a file.
 int HPWH::checkInputs() {
 	int returnVal = 0;
@@ -2949,7 +2966,8 @@ int HPWH::checkInputs() {
 
 		//check is condensity sums to 1
 		condensitySum = 0;
-		for(int j = 0; j < heatSources[i].getCondensitySize(); ++j)  condensitySum += heatSources[i].condensity[j];
+
+		for(int j = 0; j < heatSources[i].getCondensitySize(); j++)  condensitySum += heatSources[i].condensity[j];
 		if(fabs(condensitySum - 1.0) > 1e-6) {
 			if(hpwhVerbosity >= VRB_reluctant) {
 				msg("The condensity for heatsource %d does not sum to 1.  \n",i);
@@ -3215,6 +3233,21 @@ int HPWH::HPWHinit_file(string configFile) {
 				}
 				return HPWH_ABORT;
 			}
+		} else if(token == "hasHeatExchanger") {
+			// false of this model uses heat exchange
+			line_ss >> tempString;
+			if(tempString == "true") hasHeatExchanger = true;
+			else if(tempString == "false") hasHeatExchanger = false;
+			else {
+				if(hpwhVerbosity >= VRB_reluctant) {
+					msg("Improper value for %s\n",token.c_str());
+				}
+				return HPWH_ABORT;
+			}
+		} else if(token == "heatExchangerEffectiveness") {
+			// applies to heat-exchange models only
+			line_ss >> tempDouble;
+			heatExchangerEffectiveness = tempDouble;			
 		} else if(token == "verbosity") {
 			line_ss >> token;
 			if(token == "silent") {

src/HPWH.hh

@@ -216,7 +216,9 @@ public:
 		MODELS_RHEEM_HPHD60HNU_201_MP = 350,
 		MODELS_RHEEM_HPHD60VNU_201_MP = 351,
 		MODELS_RHEEM_HPHD135HNU_483_MP = 352, // really bad fit to data due to inconsistency in data
-		MODELS_RHEEM_HPHD135VNU_483_MP = 353  // really bad fit to data due to inconsistency in data
+		MODELS_RHEEM_HPHD135VNU_483_MP = 353,  // really bad fit to data due to inconsistency in data
+
+		MODELS_AQUATHERMAIRE = 400 // heat exchanger model
 	};
 
 	///specifies the modes for writing output
@@ -913,7 +915,7 @@ private:
 	/**< the mass of water (kg) in a single node  */
 	double nodeMass_kg;
 
-	/**< the heat capacity of the water (kJ/�C) in a single node  */
+	/**< the heat capacity of the water (kJ/�C) in a single node  */
 	double nodeCp_kJperC;
 
 	/**< the height in meters of the one node  */
@@ -1000,6 +1002,12 @@ private:
 	/// Generates a vector of logical nodes
 	std::vector<HPWH::NodeWeight> getNodeWeightRange(double bottomFraction,double topFraction);
 
+	/// False: water is drawn from the tank itself; True: tank provides heat exchange only
+	bool hasHeatExchanger;
+
+	/// Coefficient (0-1) of effectiveness for heat exchange between tank and water line (used by heat-exchange models only).
+	double heatExchangerEffectiveness;
+
 };  //end of HPWH class
 
 class HPWH::HeatSource {

src/HPWHpresets.cc

@@ -515,7 +515,7 @@ int HPWH::HPWHinit_presets(MODELS presetNum) {
 
 	else if (presetNum == MODELS_StorageTank) {
 		setNumNodes(12);
-		setpoint_C = F_TO_C(127.0);
+		setpoint_C = 800.;
 
 		tankSizeFixed = false;
 		tankVolume_L = GAL_TO_L(80);
@@ -3819,8 +3819,70 @@ int HPWH::HPWHinit_presets(MODELS presetNum) {
 		heatSources[1].followedByHeatSource = &heatSources[2];
 
 		heatSources[0].companionHeatSource = &heatSources[2];
-	}
+	}	
+	else if (presetNum == MODELS_AQUATHERMAIRE) { // AquaThermAire
+		setNumNodes(1);
+		setpoint_C = F_TO_C(125.);
+
+		tankVolume_L = GAL_TO_L(54.4);
+		tankUA_kJperHrC = 10.35;
+
+		doTempDepression = false;
+		tankMixesOnDraw = true;
+
+		// heat exchangers only
+		hasHeatExchanger = true;
+		heatExchangerEffectiveness = 0.9;
+
+		HeatSource compressor(this);
+
+		//compressor values
+		compressor.isOn = false;
+		compressor.isVIP = false;
+		compressor.typeOfHeatSource = TYPE_compressor;
+
+		compressor.setCondensity({1.});
 
+		//AOSmithPHPT60 values
+		compressor.perfMap.reserve(4);
+
+		compressor.perfMap.push_back({
+			5, // Temperature (T_F)
+			{-1423, 38.70 ,0.}, // Input Power Coefficients (inputPower_coeffs)
+			{-0.13839, 0.012319, 0.} // COP Coefficients (COP_coeffs)
+			});
+
+		compressor.perfMap.push_back({
+			34, // Temperature (T_F)
+			{-1558, 42.40, 0.}, // Input Power Coefficients (inputPower_coeffs)
+			{-0.19375, 0.017247, 0.} // COP Coefficients (COP_coeffs)
+			});
+
+		compressor.perfMap.push_back({
+			67, // Temperature (T_F)
+			{-1713, 46.60, 0.}, // Input Power Coefficients (inputPower_coeffs)
+			{-0.28156, 0.025064, 0.} // COP Coefficients (COP_coeffs)
+			});
+
+		compressor.perfMap.push_back({
+			95, // Temperature (T_F)
+			{-1844, 50.17, 0.}, // Input Power Coefficients (inputPower_coeffs)
+			{-0.47273, 0.042082, 0.} // COP Coefficients (COP_coeffs)
+			});
+
+		compressor.minT = F_TO_C(-25);
+		compressor.maxT = F_TO_C(125.);
+		compressor.hysteresis_dC = dF_TO_dC(1);
+		compressor.configuration = HeatSource::CONFIG_WRAPPED;
+
+		//logic conditions
+		compressor.addTurnOnLogic(HPWH::bottomTwelfth(dF_TO_dC(111)));
+		compressor.addTurnOnLogic(HPWH::standby(dF_TO_dC(14)));
+
+		//set everything in its places
+		heatSources.resize(1);
+		heatSources[0] = compressor;
+	}
 	else {
 		if (hpwhVerbosity >= VRB_reluctant) {
 			msg("You have tried to select a preset model which does not exist.  \n");

test/AquaThermAire.txt

@@ -0,0 +1,71 @@
+verbosity silent
+numNodes 1 #number of nodes
+setpoint 125 F
+volume 54.4 gal
+UA 10.35 kJperHrC
+depressTemp false
+mixOnDraw true
+hasHeatExchanger true
+heatExchangerEffectiveness 0.9
+
+#a test comment
+numHeatSources 1
+
+heatsource 0 isVIP false
+heatsource 0 isOn false
+heatsource 0 type compressor
+heatsource 0 condensity 1
+
+#we have input power and COP equations at for ambient temperatures
+heatsource 0 nTemps 4
+heatsource 0 T1 5 F
+heatsource 0 T2 34 F
+heatsource 0 T3 67 F
+heatsource 0 T4 95 F
+
+#quadratic terms for this product are zero. It's remarkably linear.
+
+#  5F Coefficients
+heatsource 0 inPowT1const -1423
+heatsource 0 inPowT1lin 38.70
+heatsource 0 inPowT1quad 0.0
+heatsource 0 copT1const -0.13839
+heatsource 0 copT1lin 0.012319
+heatsource 0 copT1quad 0.0
+
+# 34F Coefficients
+heatsource 0 inPowT2const -1558
+heatsource 0 inPowT2lin 42.40
+heatsource 0 inPowT2quad 0.0
+heatsource 0 copT2const -0.19375
+heatsource 0 copT2lin 0.017247
+heatsource 0 copT2quad 0.0
+
+# 67F Coefficients
+heatsource 0 inPowT3const -1713
+heatsource 0 inPowT3lin 46.60
+heatsource 0 inPowT3quad 0.0
+heatsource 0 copT3const -0.28156
+heatsource 0 copT3lin 0.025064
+heatsource 0 copT3quad 0.0
+
+# 95F Coefficients
+heatsource 0 inPowT4const -1844
+heatsource 0 inPowT4lin 50.17
+heatsource 0 inPowT4quad 0.0
+heatsource 0 copT4const -0.47273
+heatsource 0 copT4lin 0.042082
+heatsource 0 copT4quad 0.0
+
+
+heatsource 0 minT -25 F
+heatsource 0 maxT 125 F
+heatsource 0 hysteresis 1 F
+heatsource 0 coilConfig wrapped
+
+#Turns on when average tank temperature is 111F or colder
+heatsource 0 onlogic nodes 1 absolute < 111 F
+
+#BL not sure how to specify standby turn on. Trying this for now
+#Intent is to get it to turn on at 111F which is 14F below 125F
+heatsource 0 onlogic standby 14 F