public void addValue(Bed[] bed, Condenser cond, Evaporator eva, int timeStep)
{
array_bed1_pressure[timeStep] = bed[0].averagePressure;
array_bed2_pressure[timeStep] = bed[1].averagePressure;
array_cond_pressure[timeStep] = cond.averagePressure;
array_eva_pressure[timeStep] = eva.averagePressure;
array_bed1_phase[timeStep] = bed[0].phase;
array_bed2_phase[timeStep] = bed[1].phase;
}
public void condensationOnCondenserTubeSurface(Condenser cond, out double rateOfCondensation)
{
int r = cond.numOfRNodes_fluid + cond.numOfRNodes_tubeWall - 1;
//saturated temperature for adsorbate
double A = 8.07131, B = 1730.63, C = 233.426;
double T_sat = (B / (A - Math.Log10(cond.averagePressure * 0.00750062))) - C + 273;
//averaged wall temperature
double sum = 0;
int count = 0;
for (int z = 0; z < numOfZNodes; z++)
{
sum += T[r, z].TP;
count++;
}
double T_wall = sum / count;
//calculate modified latent heat of vaporisation
double JakobNumber = cond.adsorbate.heatCapacity_condensed * (T_sat - T_wall) / cond.adsorbate.latentHeat;
double modifiedLatentHeat = cond.adsorbate.latentHeat * (1 + 0.68 * JakobNumber);
//calculate heat transfer coefficient for film condensation
double g = 9.81; //kgm/s2
double c = 0.729; //for tube
double numerator = g * cond.adsorbate.density_condensed * (cond.adsorbate.density_condensed - cond.adsorbate.density) * Math.Pow(cond.adsorbate.thermalConductivity_condensed, 3) * modifiedLatentHeat;
double denominator = cond.adsorbate.dynamicViscosity_condensed * (T_sat - T_wall) * 2 * (cond.numOfRNodes_fluid + cond.numOfRNodes_tubeWall) * deltaR;
double heatTransferCoefficient_condensation = c * Math.Pow(Math.Abs(numerator / denominator), 0.25) * deltaZ * cond.numOfZNodes;
double heatOfCondensation = 0;
rateOfCondensation = 0;
if ((T_sat - T_wall) > 0)
{
//apply heat flux
for (int z = 0; z < numOfZNodes; z++)
{
T[r, z].aN = 0;
T[r, z].Sc = 2 * Math.PI * T[r, z].rn * deltaZ * heatTransferCoefficient_condensation * (T_sat - T_wall);
T[r, z].aP = T[r, z].aW + T[r, z].aE + T[r, z].aS + T[r, z].aN + T[r, z].aP0 - T[r, z].Sp + T[r, z].deltaF;
}
heatOfCondensation = heatTransferCoefficient_condensation * cond.tubeOuterSurfaceArea * (T_sat - T_wall);
rateOfCondensation = heatOfCondensation / modifiedLatentHeat;
}
}
public void assignBoundary_for_cond(Condenser cond)
{
int rtop = cond.numOfRNodes_fluid + cond.numOfRNodes_tubeWall;
for (int r = 0; r < rtop; r++)
{
for (int z = 0; z < numOfZNodes; z++)
{
T[r, z].boundary = Boundary.Center;
if (z == 0)
{
T[r, z].boundary = Boundary.Left;
}
else if (z == (numOfZNodes - 1))
{
T[r, z].boundary = Boundary.Right;
}
if (r == 0)
{
T[r, z].boundary = Boundary.Bottom;
if (z == 0)
{
T[r, z].boundary = Boundary.BottomLeft;
}
else if (z == (numOfZNodes - 1))
{
T[r, z].boundary = Boundary.BottomRight;
}
}
else if (r == (rtop - 1))
{
T[r, z].boundary = Boundary.Top;
if (z == 0)
{
T[r, z].boundary = Boundary.TopLeft;
}
else if (z == (numOfZNodes - 1))
{
T[r, z].boundary = Boundary.TopRight;
}
}
}
}
}
public void updateCoefficients2(double inletTemperature, Condenser cond)
{
foreach (TNodes node in T)
{
//inlet temperature
if (node.boundary == Boundary.Left || node.boundary == Boundary.BottomLeft)
{
if (node.materialType == MaterialType.HeatExchangeFluid)
{
node.Sc = (2 * node.Dw + node.Fw) * inletTemperature;
node.Sp = -(2 * node.Dw + node.Fw);
node.aP = node.aW + node.aE + node.aS + node.aN + node.aP0 - node.Sp + node.deltaF;
}
}
}
//condensation on tube surface
condensationOnCondenserTubeSurface(cond, out cond.rateOfCondensation);
}
public CondTemperaturePDE(Condenser cond)
{
deltaR = cond.deltaR;
deltaZ = cond.deltaZ;
numOfRNodes = cond.numOfRNodes;
numOfZNodes = cond.numOfZNodes;
T = cond.T;
assignBoundary_for_cond(cond);
//initial conditions
foreach (TNodes node in T)
{
node.TP0 = Parameters.T0;
node.TP = node.TP0;
}
assignCoefficients2_for_cond(cond);
}
static void Main(string[] args)
{
//define chambers
Bed[] bed = new Bed[Parameters.numOfBed];
for (int i = 0; i < Parameters.numOfBed; i++)
{
bed[i] = new Bed();
}
Condenser cond = new Condenser();
Evaporator eva = new Evaporator();
//define connecting pipes
ConnectingPipes[] connectingPipe = new ConnectingPipes[Parameters.numOfBed + 1 + 1];
connectingPipe[0] = new ConnectingPipes(bed[0], cond);
connectingPipe[1] = new ConnectingPipes(bed[1], cond);
connectingPipe[2] = new ConnectingPipes(eva, bed[0]);
connectingPipe[3] = new ConnectingPipes(eva, bed[1]);
//define time plots
TemperaurePlot temperaturePlot = new TemperaurePlot();
PressurePlot pressurePlot = new PressurePlot();
//define performance indicators
PerformanceIndicator.initialise();
Report.initialise(bed);
//starting operation
int cycle = 1;
for (int timeStep = 1; timeStep <= Parameters.numOfTimeStep; timeStep++)
{
if (timeStep > 1)
{
updateNodeAtNewTimeStep(bed[0]);
updateq(bed[0]);
updateNodeAtNewTimeStep(bed[1]);
updateq(bed[1]);
updateNodeAtNewTimeStep(cond);
updateNodeAtNewTimeStep(eva);
}
if (timeStep > ((cycle - 1) * 2 * Parameters.switchingTime * Parameters.timeStepPerSecond) && timeStep <= (Parameters.switchingTime * Parameters.timeStepPerSecond + (cycle - 1) * 2 * (Parameters.switchingTime + Parameters.sorptionTime) * Parameters.timeStepPerSecond))
{
//Phase
bed[0].phase = Phase.Preheating;
bed[1].phase = Phase.Precooling;
cond.phase = Phase.NA;
eva.phase = Phase.NA;
updateMassFlowrate(connectingPipe);
//switching time
List <Task> TaskList = new List <Task>();
Task task1 = new Task(bed[0].preheating);
task1.Start();
TaskList.Add(task1);
Task task2 = new Task(bed[1].precooling);
task2.Start();
TaskList.Add(task2);
Task task3 = new Task(cond.disconnected);
task3.Start();
TaskList.Add(task3);
Task task4 = new Task(eva.disconnected);
task4.Start();
TaskList.Add(task4);
Task.WaitAll(TaskList.ToArray());
}
else if (timeStep > ((Parameters.switchingTime + (cycle - 1) * 2 * (Parameters.switchingTime + Parameters.sorptionTime)) * Parameters.timeStepPerSecond) && timeStep <= ((Parameters.switchingTime + Parameters.sorptionTime + (cycle - 1) * 2 * (Parameters.switchingTime + Parameters.sorptionTime)) * Parameters.timeStepPerSecond))
{
//Phase
bed[0].phase = Phase.Desorption;
bed[1].phase = Phase.Adsorption;
cond.phase = Phase.Desorption;
eva.phase = Phase.Adsorption;
updateMassFlowrate(connectingPipe);
//sorption time
List <Task> TaskList = new List <Task>();
Task task1 = new Task(bed[0].desorption);
task1.Start();
TaskList.Add(task1);
Task task2 = new Task(bed[1].adsorption);
task2.Start();
TaskList.Add(task2);
Task.WaitAll(TaskList.ToArray());
cond.condensation();
eva.evaporation();
}
else if (timeStep > ((Parameters.switchingTime + Parameters.sorptionTime + (cycle - 1) * 2 * (Parameters.switchingTime + Parameters.sorptionTime)) * Parameters.timeStepPerSecond) && timeStep <= ((2 * Parameters.switchingTime + Parameters.sorptionTime + (cycle - 1) * 2 * (Parameters.switchingTime + Parameters.sorptionTime)) * Parameters.timeStepPerSecond))
{
//Phase
bed[0].phase = Phase.Precooling;
bed[1].phase = Phase.Preheating;
cond.phase = Phase.NA;
eva.phase = Phase.NA;
updateMassFlowrate(connectingPipe);
//switching time
List <Task> TaskList = new List <Task>();
Task task1 = new Task(bed[0].precooling);
task1.Start();
TaskList.Add(task1);
Task task2 = new Task(bed[1].preheating);
task2.Start();
TaskList.Add(task2);
Task task3 = new Task(cond.disconnected);
task3.Start();
TaskList.Add(task3);
Task task4 = new Task(eva.disconnected);
task4.Start();
TaskList.Add(task4);
Task.WaitAll(TaskList.ToArray());
}
else if (timeStep > ((2 * Parameters.switchingTime + Parameters.sorptionTime + (cycle - 1) * 2 * (Parameters.switchingTime + Parameters.sorptionTime)) * Parameters.timeStepPerSecond) && timeStep <= ((2 * Parameters.switchingTime + 2 * Parameters.sorptionTime + (cycle - 1) * 2 * (Parameters.switchingTime + Parameters.sorptionTime)) * Parameters.timeStepPerSecond))
{
//Phase
bed[0].phase = Phase.Adsorption;
bed[1].phase = Phase.Desorption;
cond.phase = Phase.Desorption;
eva.phase = Phase.Adsorption;
updateMassFlowrate(connectingPipe);
//sorption time
List <Task> TaskList = new List <Task>();
Task task1 = new Task(bed[0].adsorption);
task1.Start();
TaskList.Add(task1);
Task task2 = new Task(bed[1].desorption);
task2.Start();
TaskList.Add(task2);
Task.WaitAll(TaskList.ToArray());
cond.condensation();
eva.evaporation();
}
if (timeStep == cycle * 2 * (Parameters.switchingTime + Parameters.sorptionTime) * Parameters.timeStepPerSecond)
{
cycle++;
}
//reset mass flow rate to 0
resetMassFlowRate(connectingPipe);
//update aveage pressure
bed[0].calculateAveragePressure();
bed[1].calculateAveragePressure();
cond.calculateAveragePressure();
eva.calculateAveragePressure();
bed[0].calculateAverageMass();
cond.calculateAverageMass();
//update time plots
temperaturePlot.addValue(bed, cond, eva, timeStep);
pressurePlot.addValue(bed, cond, eva, timeStep);
//update performance indicators
for (int i = 0; i < Parameters.numOfBed; i++)
{
if (bed[i].phase == Phase.Preheating || bed[i].phase == Phase.Desorption)
{
//heat input
switch (i)
{
case 0:
PerformanceIndicator.addBedValue(temperaturePlot.array_bed1_inlet[timeStep], temperaturePlot.array_bed1_outlet[timeStep], timeStep);
break;
case 1:
PerformanceIndicator.addBedValue(temperaturePlot.array_bed2_inlet[timeStep], temperaturePlot.array_bed2_outlet[timeStep], timeStep);
break;
default:
Console.WriteLine("more bed than declared");
Console.Read();
break;
}
}
}
//heat output
PerformanceIndicator.addEvaValue(temperaturePlot.array_eva_inlet[timeStep], temperaturePlot.array_eva_outlet[timeStep], timeStep);
//condensatation
PerformanceIndicator.addCondensateValue(cond.rateOfCondensation, timeStep);
//output the current time step
Console.WriteLine("{0} of {1} time steps completed...", timeStep, Parameters.numOfTimeStep);
Console.WriteLine("{0}" + " " + "{1}", bed[0].averagePressure, cond.averagePressure);
Console.WriteLine("{0}" + " " + "{1}", bed[1].averagePressure, eva.averagePressure);
}
string cycleTime = (Parameters.switchingTime / 60).ToString() + "m " + (Parameters.sorptionTime / 60).ToString() + "m";
export_T(bed[0], cycleTime + " bed 1 temperature contour");
export_T(bed[1], cycleTime + " bed 2 temperature contour");
export_T(cond, cycleTime + " cond temperature contour");
export_T(eva, cycleTime + " eva temperature contour");
export_P(bed[0], cycleTime + " bed 1 pressure contour");
export_P(bed[1], cycleTime + " bed 2 pressure contour");
export_P(cond, cycleTime + " cond pressure contour");
export_P(eva, cycleTime + " eva pressure contour");
temperaturePlot.exportPlot(cycleTime + " temperature plot");
pressurePlot.exportPlot(cycleTime + " pressure plot");
PerformanceIndicator.calculatePerformance(bed, eva);
Console.WriteLine("COP is {0}", PerformanceIndicator.COP);
Report.publish(cycleTime + " report");
Console.WriteLine("Simulation is completed, press any key to close this window");
Console.Read();
}
public void TDMA2_for_cond(Condenser cond)//solve: west to east, sweep: south to north
{
int rtop = cond.numOfRNodes_fluid + cond.numOfRNodes_tubeWall;
do
{
foreach (TNodes node in T)
{
node.TP_prime = node.TP;
}
for (int r = 0; r < rtop; r++)
{
//get from neighbour lines
for (int z = 0; z < numOfZNodes; z++)
{
if (r == 0)
{
T[r, z].TS = 0;
T[r, z].TN = T[r + 1, z].TP;
}
else if (r == (rtop - 1))
{
T[r, z].TS = T[r - 1, z].TP;
T[r, z].TN = 0;
}
else
{
T[r, z].TS = T[r - 1, z].TP;
T[r, z].TN = T[r + 1, z].TP;
}
}
}
for (int r = 0; r < rtop; r++)
{
//set from west to east
for (int z = 0; z < numOfZNodes; z++)
{
T[r, z].betaj = T[r, z].aW;
T[r, z].alphaj = T[r, z].aE;
T[r, z].Dj = T[r, z].aP;
T[r, z].Cj = T[r, z].aS * T[r, z].TS + T[r, z].aN * T[r, z].TN + T[r, z].aP0 * T[r, z].TP0 + T[r, z].Sc;
if (z == 0)
{
T[r, z].Aj = T[r, z].alphaj / (T[r, z].Dj);
T[r, z].Cj_prime = (T[r, z].Cj) / (T[r, z].Dj);
}
else
{
T[r, z].Aj = T[r, z].alphaj / (T[r, z].Dj - T[r, z].betaj * T[r, z - 1].Aj);
T[r, z].Cj_prime = (T[r, z].betaj * T[r, z - 1].Cj_prime + T[r, z].Cj) / (T[r, z].Dj - T[r, z].betaj * T[r, z - 1].Aj);
}
}
}
for (int r = 0; r < rtop; r++)
{
//solve from east to west
for (int z = (numOfZNodes - 1); z >= 0; z--)
{
if (z == (numOfZNodes - 1))
{
T[r, z].TP = T[r, z].Cj_prime;
}
else
{
T[r, z].TP = T[r, z].Aj * T[r, z + 1].TP + T[r, z].Cj_prime;
}
T[r, z].TP = Parameters.relaxationFactor_temperature * T[r, z].TP + (1 - Parameters.relaxationFactor_temperature) * T[r, z].TP_prime;
if (double.IsNaN(T[r, z].TP))
{
int test = 1;
}
}
}
endOfIteration = true;
foreach (TNodes node in T)
{
node.error = Helper.calculate_error(node.TP, node.TP_prime);
if (Math.Abs(node.error) < Parameters.tolerance_temperature)
{
node.isConverged = true;
}
else
{
node.isConverged = false;
endOfIteration = false;
break;
}
}
iterationCounter++;
} while (endOfIteration == false);
}
public void assignCoefficients2_for_cond(Condenser cond)
{
int rtop = cond.numOfRNodes_fluid + cond.numOfRNodes_tubeWall;
for (int r = 0; r < rtop; r++)
{
for (int z = 0; z < numOfZNodes; z++)
{
if (r == 0)
{
T[r, z].Dw = 2 * Math.PI * T[r, z].rp * deltaR * T[r, z].thermalConductivity / deltaZ;
T[r, z].De = 2 * Math.PI * T[r, z].rp * deltaR * T[r, z].thermalConductivity / deltaZ;
T[r, z].Ds = 2 * Math.PI * T[r, z].rs * deltaZ * 0.5 * (T[r, z].thermalConductivity + T[r, z].thermalConductivity) / deltaR;
T[r, z].Dn = 2 * Math.PI * T[r, z].rn * deltaZ * 0.5 * (T[r, z].thermalConductivity + T[r + 1, z].thermalConductivity) / deltaR;
}
else if (r == (rtop - 1))
{
T[r, z].Dw = 2 * Math.PI * T[r, z].rp * deltaR * T[r, z].thermalConductivity / deltaZ;
T[r, z].De = 2 * Math.PI * T[r, z].rp * deltaR * T[r, z].thermalConductivity / deltaZ;
T[r, z].Ds = 2 * Math.PI * T[r, z].rs * deltaZ * 0.5 * (T[r, z].thermalConductivity + T[r - 1, z].thermalConductivity) / deltaR;
T[r, z].Dn = 2 * Math.PI * T[r, z].rn * deltaZ * 0.5 * (T[r, z].thermalConductivity + T[r, z].thermalConductivity) / deltaR;
}
else
{
T[r, z].Dw = 2 * Math.PI * T[r, z].rp * deltaR * T[r, z].thermalConductivity / deltaZ;
T[r, z].De = 2 * Math.PI * T[r, z].rp * deltaR * T[r, z].thermalConductivity / deltaZ;
T[r, z].Ds = 2 * Math.PI * T[r, z].rs * deltaZ * 0.5 * (T[r, z].thermalConductivity + T[r - 1, z].thermalConductivity) / deltaR;
T[r, z].Dn = 2 * Math.PI * T[r, z].rn * deltaZ * 0.5 * (T[r, z].thermalConductivity + T[r + 1, z].thermalConductivity) / deltaR;
}
}
}
foreach (TNodes node in T)
{
node.aP0 = 2 * Math.PI * node.density * node.heatCapacity * node.rp * deltaR * deltaZ / Parameters.deltat;
node.Fw = 2 * Math.PI * node.rp * deltaR * node.velocity * node.density * node.heatCapacity;
node.Fe = 2 * Math.PI * node.rp * deltaR * node.velocity * node.density * node.heatCapacity;
node.Fs = 2 * Math.PI * deltaZ * node.density * node.heatCapacity * 0 * node.rs;
node.Fn = 2 * Math.PI * deltaZ * node.density * node.heatCapacity * 0 * node.rn;
node.aW = Helper.max3(node.Fw, (node.Dw + 0.5 * node.Fw), 0);
node.aE = Helper.max3(-node.Fe, (node.De - 0.5 * node.Fe), 0);
node.aS = Helper.max3(node.Fs, (node.Ds + 0.5 * node.Fs), 0);
node.aN = Helper.max3(-node.Fn, (node.Dn - 0.5 * node.Fn), 0);
node.Sc = 0;
node.Sp = 0;
switch (node.boundary)
{
case Boundary.Left:
node.aW = 0;
break;
case Boundary.Right:
node.aE = 0;
break;
case Boundary.Bottom:
node.aS = 0;
break;
case Boundary.Top:
node.aN = 0;
break;
case Boundary.BottomLeft:
node.aW = 0;
node.aS = 0;
break;
case Boundary.BottomRight:
node.aE = 0;
node.aS = 0;
break;
case Boundary.TopLeft:
node.aW = 0;
node.aN = 0;
break;
case Boundary.TopRight:
node.aE = 0;
node.aN = 0;
break;
default:
break;
}
node.deltaF = node.Fe - node.Fw + node.Fn - node.Fs;
node.aP = node.aW + node.aE + node.aS + node.aN + node.aP0 - node.Sp + node.deltaF;
}
}
public void addValue(Bed[] bed, Condenser cond, Evaporator eva, int timeStep)
{
double sum_in, sum_out;
double value_in, value_out;
//for beds
for (int i = 0; i < Parameters.numOfBed; i++)
{
sum_in = 0;
sum_out = 0;
value_in = 0;
value_out = 0;
//inlet temperature
for (int r = 0; r < bed[i].numOfRNodes_fluid; r++)
{
sum_in += bed[i].T[r, 0].TP;
}
value_in = sum_in / bed[i].numOfRNodes_fluid;
//outlet temperature
for (int r = 0; r < bed[i].numOfRNodes_fluid; r++)
{
sum_out += bed[i].T[r, (bed[i].numOfZNodes - 1)].TP;
}
value_out = sum_out / bed[i].numOfRNodes_fluid;
switch (i)
{
case 0:
array_bed1_inlet[timeStep] = value_in;
array_bed1_outlet[timeStep] = value_out;
break;
case 1:
array_bed2_inlet[timeStep] = value_in;
array_bed2_outlet[timeStep] = value_out;
break;
default:
Console.WriteLine("more beds are sued than declared");
Console.Read();
break;
}
}
//for condenser
sum_in = 0;
sum_out = 0;
value_in = 0;
value_out = 0;
//inlet temperature
for (int r = 0; r < cond.numOfRNodes_fluid; r++)
{
sum_in += cond.T[r, 0].TP;
}
value_in = sum_in / cond.numOfRNodes_fluid;
//outlet temperature
for (int r = 0; r < cond.numOfRNodes_fluid; r++)
{
sum_out += cond.T[r, (cond.numOfZNodes - 1)].TP;
}
value_out = sum_out / cond.numOfRNodes_fluid;
array_cond_inlet[timeStep] = value_in;
array_cond_outlet[timeStep] = value_out;
//for evaporator
sum_in = 0;
sum_out = 0;
value_in = 0;
value_out = 0;
//inlet temperature
for (int r = 0; r < eva.numOfRNodes_fluid; r++)
{
sum_in += eva.T[r, 0].TP;
}
value_in = sum_in / eva.numOfRNodes_fluid;
//outlet temperature
for (int r = 0; r < eva.numOfRNodes_fluid; r++)
{
sum_out += eva.T[r, (eva.numOfZNodes - 1)].TP;
}
value_out = sum_out / eva.numOfRNodes_fluid;
array_eva_inlet[timeStep] = value_in;
array_eva_outlet[timeStep] = value_out;
}