Buildings.Controls.OBC.ASHRAE.G36.Plants.Chillers.Validation
Collection of validation models
Information
This package contains validation models for the classes in Buildings.Controls.OBC.ASHRAE.G36.Plants.Chillers.HeadPressure.
Note that most validation models contain simple input data which may not be realistic, but for which the correct output can be obtained through an analytic solution. The examples plot various outputs, which have been verified against these solutions. These model outputs are stored as reference data and used for continuous validation whenever models in the library change.
Package Content
| Name | Description |
|---|---|
 Controller
|
Validation head pressure controller |
Buildings.Controls.OBC.ASHRAE.G36.Plants.Chillers.Validation.Controller
Validation head pressure controller
Information
This example validates composed chiller plant controller Buildings.Controls.OBC.ASHRAE.G36.Plants.Chillers.Controller. It shows the process of enabling plant, enabling waterside economizer and staging up one chiller. The plant:
- is less coupled;
- has waterside economizer and the chilled water flow through the economizer is controlled using heat exchanger pump;
- has 2 parallel identical chillers and do not have head pressure control signal;
- has 2 headed chilled water pumps, 1 remote differential pressure sensor and do not have local differential pressure sensor hardwired to the plant controller;
- has 2 headed variable speed condenser water pumps;
- has cooling tower with 2 cells.
The example shows following process:
-
At 15 minutes, the plant becomes enabled in waterside economizer mode. The
economizer is enabled and the heat exchanger pump starts operating
(
wseSta.yPumSpeis greater than 0). The condenser water pump becomes enabled and the number (1) of enabling pumps is specified by the parameterdesConWatPumNumand it starts operating at speed (0.5) specified by (desConWatPumSpe). The cooling tower cell 1 becomes enabled and its isolation valve starts open. After 5 minutes (chaTowCelIsoTim) at 20 minutes when the isolation valve is fully open, it turns on the cell 1. -
At 115 minutes, the plant starts staging up (
staSetCon.yUp=true,upProCon.yStaPro=true) and it stages up chiller 1. -
In the staging up process, at 127.07 minutes, it increases the condenser water
pump speed (0.6) and increases number (2) of the pump. Also, it starts staging up
cooling tower (
upProCon.yTowStaUp=true) at the same moment. At 127.241 minutes, it enables the chiller 1 head pressure control. When the chilled water isolation valve is fully open at 132.741 minutes, it then turns on chiller 1. The staging up process is done (upProCon.yStaPro=false).
Modelica definition
model Controller "Validation head pressure controller"
Buildings.Controls.OBC.ASHRAE.G36.Plants.Chillers.Controller chiPlaCon(
dTChiMinLif={12,12},
dTChiMaxLif={18,18},
TOutWetDes=288.15,
minFloSet={0.0089,0.0089},
maxFloSet={0.025,0.025},
nPum_nominal=2,
have_modPosChiVal=true,
final closeCoupledPlant=false,
final nChi=2,
final have_parChi=true,
final have_ponChi=false,
final TChiWatSupMin={278.15,278.15},
final heaExcAppDes=2,
final nChiWatPum=2,
final nSenChiWatPum=1,
final nConWatPum=2,
final have_heaConWatPum=true,
final conWatPumStaMat=[0,0; 1,0; 1,0; 1,1; 1,1; 1,1],
final staMat=[1,0; 1,1],
final desConWatPumSpe={0,0.5,0.75,0.5,0.75,0.9},
final towCelOnSet={0,1,1,2,2,2},
final nTowCel=2,
final cooTowAppDes=2,
VHeaExcDes_flow=0.015,
VChiWat_flow_nominal=0.5,
final dpChiWatMax={10*6894.76},
final TPlaChiWatSupMax=291.15,
final have_WSE=true,
final chiDesCap={200,200},
final chiMinCap={20,20},
final chiTyp={Buildings.Controls.OBC.ASHRAE.G36.Plants.Chillers.Types.ChillersAndStages.PositiveDisplacement,
Buildings.Controls.OBC.ASHRAE.G36.Plants.Chillers.Types.ChillersAndStages.PositiveDisplacement},
TConWatSup_nominal={293.15,293.15},
TConWatRet_nominal={303.15,303.15},
watLevMin=0.7,
watLevMax=1)
"Chiller plant controller";
Buildings.Controls.OBC.CDL.Reals.Sources.TimeTable timTabLin1(
final smoothness=Buildings.Controls.OBC.CDL.Types.Smoothness.ConstantSegments,
final table=[0,2; 600,4; 1200,6; 1800,6; 2400,8; 3000,8; 3600,8; 4200,6; 4800,6;
5400,6; 6000,7; 6600,7; 7200,7])
"Time table with smoothness method of constant segments";
Buildings.Controls.OBC.CDL.Conversions.RealToInteger reaToInt1
"Convert real to integer";
Buildings.Controls.OBC.CDL.Reals.Sources.Ramp TChiWatSup(
final height=4,
final duration=7200,
final offset=273.15 + 7) "Chilled water supply";
Buildings.Controls.OBC.CDL.Reals.Sources.Constant phi(final k=0.65)
"Outdoor relative humidity";
Buildings.Controls.OBC.CDL.Reals.Sources.Constant TOut1(
final k=313.15) "Outdoor dry bulb temperature";
Buildings.Controls.OBC.CDL.Reals.Sources.Ramp TChiWatRetUp(
final height=5,
final duration=3600,
final offset=273.15 + 15)
"Chilled water return temperature, upstream of WSE";
Buildings.Controls.OBC.CDL.Reals.Sources.Ramp TChiWatRetDow(
final height=3,
final duration=3600,
final offset=273.15 + 10) "Chilled water return downstream of WSE";
Buildings.Controls.OBC.CDL.Reals.Sources.Constant TConWatRet(
final k=307.15)
"Condenser water return temperature";
Buildings.Controls.OBC.CDL.Reals.Sources.Constant TConWatSup(
final k=305.15)
"Condenser water supply temperature";
Buildings.Controls.OBC.CDL.Reals.Sources.Ramp dpChiWat(
final height=2*6895,
final duration=3600,
final offset=3*6895,
final startTime=0) "Chilled water differential pressure";
Buildings.Controls.OBC.CDL.Reals.Sources.Ramp watLev(
final height=1.2,
final duration=3600,
final offset=0.5) "Water level in cooling tower";
Buildings.Controls.OBC.CDL.Integers.GreaterThreshold intGreThr
"Check if the WSE pump should be enabled";
Buildings.Controls.OBC.CDL.Reals.Sources.Ramp TEntHex(
final height=3,
final duration=3600,
final offset=273.15 + 14)
"Chilled water temperature entering heat exchanger";
Buildings.Controls.OBC.CDL.Reals.Sources.TimeTable chiWatFlo(
final smoothness=Buildings.Controls.OBC.CDL.Types.Smoothness.LinearSegments,
final table=[0,0; 6500,0; 7000,0.005; 7500,0.008; 9200,0.02; 10000,0.020;
10800,0.024],
extrapolation=Buildings.Controls.OBC.CDL.Types.Extrapolation.HoldLastPoint)
"Time table with smoothness method of constant segments";
Buildings.Controls.OBC.CDL.Logical.Pre chiOne "Chiller one status";
Buildings.Controls.OBC.CDL.Logical.Pre chiTwo
"Chiller two status";
Buildings.Controls.OBC.CDL.Logical.Pre conWatPum[2]
"Condenser water pump status setpoint";
Buildings.Controls.OBC.CDL.Logical.Pre towSta[2] "Tower cell status";
Buildings.Controls.OBC.CDL.Logical.Sources.Constant plaEna(final k=true)
"Plant enable";
Buildings.Controls.OBC.CDL.Reals.Sources.Ramp TChiWatRetDow1(
final height=10,
final duration=3600,
final offset=273.15 + 15) "Chilled water return downstream of WSE";
Buildings.Controls.OBC.CDL.Logical.Pre chiWatPum[2]
"Chilled water pumps";
Buildings.Controls.OBC.CDL.Discrete.ZeroOrderHold zerOrdHol7[2](
final samplePeriod=fill(10, 2))
"Output the input signal with a zero order hold";
Buildings.Controls.OBC.CDL.Reals.MultiplyByParameter gai(
k=0.5) "Times the nominal flow rate";
Buildings.Controls.OBC.CDL.Reals.Sources.Ramp TChiWatEntChi(
final height=2.8,
final duration=3600,
final offset=273.15 + 9.5) "Chilled water return, entering chiller";
equation
connect(timTabLin1.y[1], reaToInt1.u);
connect(reaToInt1.y, chiPlaCon.TChiWatSupResReq);
connect(phi.y, chiPlaCon.phi);
connect(TChiWatRetUp.y, chiPlaCon.TChiWatRetUp);
connect(TChiWatSup.y, chiPlaCon.TChiWatSup);
connect(TChiWatRetDow.y, chiPlaCon.TChiWatRetDow);
connect(TConWatSup.y, chiPlaCon.TConWatSup);
connect(watLev.y, chiPlaCon.watLev);
connect(dpChiWat.y, chiPlaCon.dpChiWat_remote[1]);
connect(reaToInt1.y, chiPlaCon.chiPlaReq);
connect(reaToInt1.y, intGreThr.u);
connect(intGreThr.y, chiPlaCon.uEcoPum);
connect(TEntHex.y, chiPlaCon.TEntHex);
connect(chiPlaCon.yChi[1], chiOne.u);
connect(chiPlaCon.yChi[2], chiTwo.u);
connect(chiOne.y, chiPlaCon.uChiWatReq[1]);
connect(chiOne.y, chiPlaCon.uConWatReq[1]);
connect(chiOne.y, chiPlaCon.uChi[1]);
connect(chiTwo.y, chiPlaCon.uChiWatReq[2]);
connect(chiTwo.y, chiPlaCon.uConWatReq[2]);
connect(chiTwo.y, chiPlaCon.uChi[2]);
connect(chiPlaCon.yConWatPum, conWatPum.u);
connect(conWatPum.y, chiPlaCon.uConWatPum);
connect(chiPlaCon.yTowCel, towSta.u);
connect(towSta.y, chiPlaCon.uTowSta);
connect(plaEna.y, chiPlaCon.uPlaSchEna);
connect(TConWatRet.y, chiPlaCon.TConWatTowRet);
connect(TConWatRet.y, chiPlaCon.TConWatRet[1]);
connect(TConWatRet.y, chiPlaCon.TConWatRet[2]);
connect(TChiWatSup.y, chiPlaCon.TChiWatSupChi[1]);
connect(TChiWatSup.y, chiPlaCon.TChiWatSupChi[2]);
connect(chiPlaCon.yChiWatIsoVal, zerOrdHol7.u);
connect(zerOrdHol7.y, chiPlaCon.uChiWatIsoVal);
connect(TChiWatRetDow1.y, chiPlaCon.TOut);
connect(chiPlaCon.yChiWatPum, chiWatPum.u);
connect(chiWatPum.y, chiPlaCon.uChiWatPum);
connect(chiPlaCon.yChiPumSpe, gai.u);
connect(gai.y, chiPlaCon.VChiWat_flow);
connect(TChiWatEntChi.y, chiPlaCon.TChiWatEntChi);
end Controller;