Tech Controllers ST-976 - PID Operation Algorithm; Damping

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4.2.4 PIDoperationalgorithm
IfPIDcontrolfunctionisactive,thefanandfeederoperationdependoncurrentCHboilertemperatureand
thefluegastemperature.
Thistypeofcontrollercalculatestheblowforceonthebasisof CH boiler temperature and the flue gas
temperaturemeasuredattheCHboileroutlet.Thefanoperatescontinuouslyandtheblowforcedependson
theCHboilertemperature,thefluegastemperatureaswellasthedifferencebetweentheseparametersand
theirpre‐setvalues.OneofthegreatestadvantagesofPIDregulatorsistheirabilitytomaintainastablepre‐
settemperaturewithoutunnecessaryoverregulationandoscillations.
Usingthistypeofregulatorwithafluegassensorhelpstoreducefuelcostsbyuptoseveralpercent.
Moreover,itensuresstabletemperatureofoutputwaterthusprolongingthelifeoftheheatexchanger(of
theCHboiler).Fluegastemperaturecontrolattheoutletresultsinlowemissionofdustandenvironmentally
harmfulgases.Fluegasheatisnotdisposedofthroughthechimney,butitisutilisedforheatingpurposes.
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Testresults:TECHcontrollerwithPIDcontrol
Testresults:TECHcontrollerwithoutPIDcontrol
4.2.5 Damping
Itmaybeactivatedbytheuserinthemainmenuorbythesoftwareincertaincircumstances(e.g.before
automaticcleaningprocedure,afterasuddentemperatureincreaseof5⁰Corafterflamelossinoperation
mode).
Dampingisatwo‐stageprocess.Thedurationofthesestagesmaybeadjustedinthefitter’smenu.
1. Dampingprotection
Thefeederisdisabledandthefanoperatesatthespeeddefinedbythefitterinthefitter’smenu.Thisphase
lastsuntilthesensordetectsflameloss.
2. Dampingdelay
Thefanoperatesatfullspeed.