Hot water heating yesterday...

Hot water heating … and today n Principle –Heating system n Heat source n Distribution network n Heat emitter –Heat transfer medium n water n steam n air

Hot-water heating n Terminology Boiler Radiator Main supply/return pipe Branch supply/return pipe Radiator valve Vent cock Drain/feed cock Shutoff valves Expansion tank Manual Control valve Radiator

Heating system design Initial information about the building –Type n industrial, office, dwelling –Operation n continuous, intermittent n single, multiple –Structure n heavy, light n new, reconstruction

Heating system design Functional requirements n Connection of the heat emitters with the heat source n Deaeration n Draining n Integration into the building

Heating system design Optimisation criterions   Length of the pipes   Location of the heat emmiters   Control of the system   Investment costs   Operational costs   Maintenance

Design parameters of hot water heating systems – –(1)Water circulation – –(2) Geometry of the system – –(3) Water temperature – –(4) Expansion vessel – –(5)Materials

Water circulation n Natural – without pump P1=h.ρ 1.g P2=h.ρ 2.g ΔP F =ΔP n + ΔP P n Forced – with pump ΔP n =P 2 -P 1 =h.(ρ 2 - ρ 1 ).g P2P2 P1P1

Geometry of the system n Relative connection of the heat emitters –One-pipe, two-pipe n Main pipe lay-out –Upper, lower, combined n Branch pipes lay-out –vertical, horizontal, microbore

Geometry of the system Relative connection of the heat emitters n Relative connection of the heat emitters –Two-pipe system –One-pipe system

Two-pipe systems n Contraflow, parallel flow Tichelmann

One-pipe systems Basic schemes of the connection WithWith mixing valve Two-point One-point With By-Pass With By-Pass –“Horse Rider“ – Controlled by-pass SerialSerial

One-pipe systems Mixing valves Two-point valves One-point valves Ventil compact

On-pipe systems Horse -rider Low pressure radiator valves

Relative connection of the heat emitters Conclusion Two-pipe X one-pipe system – –Length of the pipes – –Water circulation – –Measuring and control – –Pressures in the system

Geometry of the system Main-pipe layout Upper Lower Combined

Branch pipes lay-out Vertical Horizontal Hvězdicová Microbore