Hot water heating yesterday.... Hot water heating … and today n Principle –Heating system n Heat source n Distribution network n Heat emitter –Heat transfer.

Hot water heatingHot water heatingyesterday...yesterday...

Hot water heating Hot water heating … and today… and today

PrinciplePrinciple– Heating systemHeating system

Heat sourceHeat source Distribution Distribution

networknetwork Heat emitterHeat emitter

– Heat transfer Heat transfer mediummedium

waterwater steamsteam airair

Expansion vessel

Heat emmiter

Boilerl

H

T 1 , 1

T 2 , 2 Supply

Return

Expansion vessel

Heat emmiter

Boilerl

H

T 1 , 1

T 2 , 2 Supply

Return

Hot-water heatingHot-water heating

TerminologyTerminology

Boiler

Radiator

Main supply/return pipe

Branch supply/return pipe

Radiator valve

Ventcock

Drain/feed cock

Shutoff valves

Expansion tank

Manual Control valve

Radiator

Heating system designHeating system designInitial information about Initial information about

the buildingthe building– TypeType

industrial, office, dwellingindustrial, office, dwelling

– OperationOperation continuous, intermittentcontinuous, intermittent single, multiplesingle, multiple

– StructureStructure heavy, light heavy, light new, reconstructionnew, reconstruction

Heating system design Heating system design Functional requirFunctional requireementsments

Connection of the heat emitters Connection of the heat emitters with the heat sourcewith the heat source

DeaerationDeaeration DrainingDraining Integration into the buildingIntegration into the building

Heating system design Heating system design Optimisation criterionsOptimisation criterions

Length of the pipes Location of the heat emmiters Control of the system Investment costs Operational costs Maintenance

Design parameters of hot Design parameters of hot water heating systemswater heating systems

– (1) Water circulation– (2) Geometry of the system– (3) Water temperature– (4) Expansion vessel – (5) Materials

Water circulationWater circulation

Natural – without Natural – without pumppump

Expansion vessel

Heat emmiter

Boilerl

H

T 1 , 1

T 2 , 2 Supply

Return

Expansion vessel

Heat emmiter

Boilerl

H

T 1 , 1

T 2 , 2 Supply

Return

P1=h.ρ1 .g

P2=h.ρ2.g

ΔPF=ΔPn + ΔPP

Forced – with pumpForced – with pump

ΔPn=P2-P1=h.(ρ2- ρ1 ).g

P2P1

Geometry of the systemGeometry of the system

Relative connection of the heat Relative connection of the heat emittersemitters– One-pipe, two-pipeOne-pipe, two-pipe

Main pipe lay-outMain pipe lay-out– Upper, lower, combinedUpper, lower, combined

Branch pipes lay-out Branch pipes lay-out – vertical, horizontal , microborevertical, horizontal , microbore

Geometry of the system Geometry of the system Relative connection of the heat Relative connection of the heat

emittersemitters

Relative connection of the heat Relative connection of the heat emittersemitters

– Two-pipe systemTwo-pipe system

– One-pipe systemOne-pipe system

Two-pipe systemsTwo-pipe systems Contraflow, parallel flowContraflow, parallel flow

Tichelmann

One-pipe systemsBasic schemes of the connection

•With mixing valveWith mixing valve •Two-point•One-point

• With By-PassWith By-Pass –“Horse Rider“ – Controlled by-pass

•SerialSerial

One-pipe systemsMixing valves

Two-point valves

One-point valves

Ventil compact

On-pipe systemsOn-pipe systemsHorse -riderHorse -rider

Low pressure radiator valves

Relative connection of the Relative connection of the heat emittersheat emitters

ConclusionConclusion

Two-pipe X one-pipe system

– Length of the pipes– Water circulation – Measuring and control– Pressures in the system

Geometry of the systGeometry of the systeemm Main-pipe layoutMain-pipe layout

Upper

Lower

Combined

Branch pipes lay-outBranch pipes lay-out

Vertical

Horizontal

Microbore