Temperature Operational temperature Design temperature Expansion vessel System supply t1 Systém return t2 Emitter supply tw1 Emitter return tw2 Mean emitter temperature tw tw1 tTp,max Heat emmiter T1,1 tw2 Supply t1 Boiler l tw T2,2 Return t2 Maximal emitter surface temperature tTp max Temperature difference.
Download ReportTranscript Temperature Operational temperature Design temperature Expansion vessel System supply t1 Systém return t2 Emitter supply tw1 Emitter return tw2 Mean emitter temperature tw tw1 tTp,max Heat emmiter T1,1 tw2 Supply t1 Boiler l tw T2,2 Return t2 Maximal emitter surface temperature tTp max Temperature difference.
Slide 1
Temperature
Operational temperature
Design temperature
Expansion
vessel
System supply t1
Systém return t2
Emitter supply tw1
Emitter return tw2
Mean emitter temperature tw
tw1
tTp,max
Heat
emmiter
T1,1
tw2
Supply
t1
Boiler
l
tw
T2,2
Return
t2
Maximal emitter surface temperature tTp max
Temperature difference - emitter = tw1 - tw2
Temperature difference system = t1 - t2
H
Slide 2
Temperature in the system
Heat transferred
by the system
Q M c t1 t2
Heat transferred
by the emitter
Q t h A t w ti
Expansion
vessel
tw1
tp1,max
Heat
emmiter
T1,1
tw2
Supply
t1
Boiler
l
T2,2
Return
t2
tw
H
Slide 3
Temperatures
Design Criterions
Economical criterions
Physical properties of the medium
Hygiene requirements
Technical properties of the heat source
Slide 4
Temperature
Parameters design
Heating system supply temperature
Low- temperature
Medium - temperature
High temperature
t1 <=65°C
65°C< t1 <= 115°C
t1 > 115°C
Temperature difference
– 10K - 25K, high temperature 40K - 50K.
– 90/70 °C, 80/60°C, 75/55°C, 55/45°C
Slide 5
Temperature Parameters
Design
Emitter
– Maximal surface temperature (85 - 90°C)
tTp max t w1 2,5
– Temperature difference
Two-pipe = system temperature difference (15
- 25 K)
one-pipe < system temperature difference OS
(5 - 10 K)
Slide 6
Piping materials
– The material should be selected at the
beginning of the design process
– Used materials
steel
copper
plastic
Slide 7
Piping materials
Steel
Traditional material
Welding
Slide 8
Piping material
Copper
Lower material usage
Chemical reaction with water pH min7
Electrochemical corrosion (Al)
soldering , torch brazing
Slide 9
Piping material
Plastic
Materials
Netted polyethylene (PEX, VPE),
polybuten (polybutylen, polybuten-1,PB),
polypropylen (PP-R, PP-RC,PP-3),
Chlorided PVC (C-PVC, PVC-C)
Multilayer pipes with metal
Life-cycle !!!
Oxygen barierre ?
Slide 10
Heating system hydraulic
calculation
Slide 11
Calculation
Temp difference setup
Transferred output
Circulation mode
Hydraulic scheme,
sections, circuits
Water flow rate
Slide 12
Design of the pipe diameter
Natural circulation
– method given pressure difference
buoyancy
Forced circulation
– method economical specific pressure loss
60 - 200 Pa.m-1
– method optimal velocity
0,05 - 1,0 m.s-1 (!!! Noise)
– method given pressure difference
buoyancy + pump head
10-70 kPa
Slide 13
Pressure loss calculation
Pressure loss
– friction
– Local resistance
Pressure loss of the circuit compare
with the pump head
Pressure
excess is
reduced by the
control valves
Pressure
lack –
must be changed
the pump or
redesigned the
system
Temperature
Operational temperature
Design temperature
Expansion
vessel
System supply t1
Systém return t2
Emitter supply tw1
Emitter return tw2
Mean emitter temperature tw
tw1
tTp,max
Heat
emmiter
T1,1
tw2
Supply
t1
Boiler
l
tw
T2,2
Return
t2
Maximal emitter surface temperature tTp max
Temperature difference - emitter = tw1 - tw2
Temperature difference system = t1 - t2
H
Slide 2
Temperature in the system
Heat transferred
by the system
Q M c t1 t2
Heat transferred
by the emitter
Q t h A t w ti
Expansion
vessel
tw1
tp1,max
Heat
emmiter
T1,1
tw2
Supply
t1
Boiler
l
T2,2
Return
t2
tw
H
Slide 3
Temperatures
Design Criterions
Economical criterions
Physical properties of the medium
Hygiene requirements
Technical properties of the heat source
Slide 4
Temperature
Parameters design
Heating system supply temperature
Low- temperature
Medium - temperature
High temperature
t1 <=65°C
65°C< t1 <= 115°C
t1 > 115°C
Temperature difference
– 10K - 25K, high temperature 40K - 50K.
– 90/70 °C, 80/60°C, 75/55°C, 55/45°C
Slide 5
Temperature Parameters
Design
Emitter
– Maximal surface temperature (85 - 90°C)
tTp max t w1 2,5
– Temperature difference
Two-pipe = system temperature difference (15
- 25 K)
one-pipe < system temperature difference OS
(5 - 10 K)
Slide 6
Piping materials
– The material should be selected at the
beginning of the design process
– Used materials
steel
copper
plastic
Slide 7
Piping materials
Steel
Traditional material
Welding
Slide 8
Piping material
Copper
Lower material usage
Chemical reaction with water pH min7
Electrochemical corrosion (Al)
soldering , torch brazing
Slide 9
Piping material
Plastic
Materials
Netted polyethylene (PEX, VPE),
polybuten (polybutylen, polybuten-1,PB),
polypropylen (PP-R, PP-RC,PP-3),
Chlorided PVC (C-PVC, PVC-C)
Multilayer pipes with metal
Life-cycle !!!
Oxygen barierre ?
Slide 10
Heating system hydraulic
calculation
Slide 11
Calculation
Temp difference setup
Transferred output
Circulation mode
Hydraulic scheme,
sections, circuits
Water flow rate
Slide 12
Design of the pipe diameter
Natural circulation
– method given pressure difference
buoyancy
Forced circulation
– method economical specific pressure loss
60 - 200 Pa.m-1
– method optimal velocity
0,05 - 1,0 m.s-1 (!!! Noise)
– method given pressure difference
buoyancy + pump head
10-70 kPa
Slide 13
Pressure loss calculation
Pressure loss
– friction
– Local resistance
Pressure loss of the circuit compare
with the pump head
Pressure
excess is
reduced by the
control valves
Pressure
lack –
must be changed
the pump or
redesigned the
system