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Balancing methods
TA Hydronic College Training
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What is the purpose of balancing ?
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Adjusting the design flows in all terminal units in design conditions (when all control valves are fully open), while creating minimum additional pressure drops.
1) Call Santa Claus! 2) Have a method.
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Infinity of possible balancing solutions
3
100 100 100 100 100
0.5 psi 1 psi 2 psi 3 psi 4 psi
3 psi 2 psi
1 psi 1 psi 1 psi 0.5 psi 0.5 psi
100 100 100 100 100
100 100 100 100 100
2.5 psi
9.5 psi
= 7.5 psi = 17.3 ft
= 9.5 psi = 21.9 ft
= 16.5 psi = 38 ft
1.
2.
3. ...
3 psi 2 psi 3 psi
3 psi 4 psi 5 psi 6 psi
10 psi 11 psi 12 psi 13 psi
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Building brick: the hydronic module
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Main balancing valve
1 balancing valve per circuit
Direct return piping 1 2
3
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Splitting into modules
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Splitting into modules
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Simplifying the drawing is essential
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Splitting into modules
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=Solution for the main module
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Splitting into modules
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=Another solution for the main module
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Turning direction criteria for splitting into modules
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At any bifurcation between many and many units turn in the direction of the main flow
At any bifurcation between one and many units turn in the direction of the many units regardless of the flow
30 gpm 30 gpm 4 gpm 4 gpm 4 gpm 30 gpm 4 gpm 4 gpm 4 gpm
Remark: bifurcations can be or
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Splitting into modules
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=Find out the sub-modules (1)
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Splitting into modules
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=Find out the sub-modules (2)
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Splitting into modules
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= Find out the sub-modules (3)
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Splitting into modules
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A
A.5
A.4
A.6
=
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Where to install balancing valves ?
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Where would you install balancing valves ?
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Exercise: Split the plant into modules and place valves
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All black numbers is q in gpm All red numbers is ∆p in psi
Mark with where STAD/F is needed, use the smallest amount! Size all STAD/F regardless of pipe ∆p
6/2
4/2 3/2 1/1
1/1
2/2 4/2 5/2
7/3
7/3
5/2
10/4 10/4
8/3 8/3 1/1
2/2
12/4 1/1 4/2 4/2
2/2
2/2 2/2
2/2 2/2
2/2
2/2
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Exercise: Split the plant into modules, place and calculate valves
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All black numbers is q in gpm All red numbers is ∆p in psi All blue numbers in feet All circuit length is 10 feet
Mark with where STAD/F is needed, use the smallest amount! Size all pipes and STAD/F in TA Select Compare the valve size from the previous exercise
60 60 60 100
30
60
60
60
150 150 60 60
150
60
60
60
30 90
30 60 60
90 60 60
60
60
5
100
6/2
4/2 3/2 1/1
1/1
2/2 4/2 5/2
7/3
7/3
5/2
10/4 10/4
8/3 8/3 1/1
2/2
12/4 1/1 4/2 4/2
2/2
2/2 2/2
2/2 2/2
2/2
2/2
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Balancing a module
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The iterative method (trial and error) quickly becomes a nightmare because of hydraulic interactivity
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Balancing a module
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Exploit the proportion
rule
100
30 20 10 20 20
150
45 30 15 30 30
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Balancing a module
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The proportion rule applies itself downstream
from a perturbation
10 10 10 10 10
11 12 0 13 13
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Balancing methods
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Proportional method adapted from air system balancing methodologies not optimal in pressure drops
Compensated method (Pr. Robert Petitjean) designed for application with balancing valves optimal in pressure drops
TA Balance method (Pr. Robert Petitjean)
fully computerized: automatic determination of the index valve optimal in pressure drops
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The compensated method
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Reference valve
Preset the reference valve for a pressure drop of at least 1 ft at design flow. (use calculation disk or TA SCOPE)
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The compensated method
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100%
Partner valve
Obtain the design flow in the reference valve by adjusting the partner valve.
Reference valve
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The compensated method
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Reference valve Partner
valve
Maintain the flow in the reference valve, by adjusting the Partner valve, while adjusting valve no 4. (by using the computer method in TA SCOPE on no 4)
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The compensated method
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100%
100%
Continue the procedure with valve no 3. The flow is maintained in the reference valve and in valve no 4 by virtue of the proportion rule. Continue until all valves is balanced in this module.
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The compensated method
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Reliable Each valve is adjusted only once Minimum pressure drops
3 people needed 2 instruments needed Difficult if the index
is not the reference
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Order for balancing modules
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A
A.5
A.4
A.6
=The structure of hydronic modules can be seen as a hierarchical tree. By virtue of the proportion rule, before a valve can be adjusted, all its children valves must themselves be adjusted. Before a module can be balanced, the whole descent of this module must be balanced.
1 3
2
4
Balancing order:
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Order for balancing modules
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Correct
Correct
Incorrect !
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Setting of balancing valves by step 1
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Fully open
50% open
Balanced
Module @ work
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Setting of balancing valves by step 2
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Fully open
50% open
Balanced
Module @ work
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Setting of balancing valves by step 3
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Fully open
50% open
Balanced
Module @ work
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Setting of balancing valves by step 4
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Fully open
50% open
Balanced
Module @ work
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Setting of balancing valves by step 5
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Fully open
50% open
Balanced
Module @ work
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Setting of balancing valves by step 6
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Fully open
50% open
Balanced
Module @ work
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Setting of balancing valves by step 7
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Fully open
50% open
Balanced
Module @ work
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Setting of balancing valves by step 8
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Fully open
50% open
Balanced
Module @ work
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TA Balance method
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TA Balance is a computerized balancing method incorporated in the TA SCOPE:
1. Two measurements are performed on each valve
2. It calculates the best settings for the balancing valves of the module
Preliminary operations: • Partner valve is fully open • Balancing valves of all circuits are set at 50% opening
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TA Balance method
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For each valve : 1) Enter the design flow 2) Enter valve and setting 3) Measure the current flow 4) Shut the valve 5) Measure the pressure drop 6) Re-open the valve Repeat on all module valves For the partner valve : 1) Shut the valve 2) Measure the differential pressure 3) Re-open the valve
TA SCOPE calculates and displays the required valve openings.
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TA Balance method
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The settings displayed by the TA SCOPE are adopted: Circuits of the module are then proportionally balanced. With the lowest pressure drops in the valves. (starting
with selected min ∆p in the index valve)
Setting the partner valve to the design flow, now or in a later stage Gives the correct flows in every balancing valves of the module.
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TA Balance method
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Reliable Minimum pressure drops
Only one person needed Only one instrumet needed The index valve is
automatically detected Overall gain of 25% on
the balancing time
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Balancing methods
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Proportional method adapted from air system balancing methodologies not optimal in pressure drops minimum 2 to 3 access to each valve 1 man; 1 instrument
Compensated method (Pr. Robert Petitjean)
designed for application with balancing valves optimal in pressure drops only 1 access to each valve (if index valve at the end) 3(2) men; 2 instruments needed
TA Balance method (Pr. Robert Petitjean)
fully computerized: automatic determination of the index valve optimal in pressure drops 1 man; 1 instrument 3 to 4 access to each valve
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Balancing reveals the optimal set-point
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Minimum pressure drops in the balancing valves
All the pump head in excess is located in the main valve
Re-open the main valve and adjust the pump speed
1
2
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Pump optimization
All above 1 ft (0.5 psi) in ∆p in the index valve and main valve is energy waste….
….no balancing is completed before the pump is optimized
50 gpm
250 gpm
40 psi
14 psi 10.5 psi
50 gpm 50 gpm 50 gpm 50 gpm
13 psi 12 psi 11 psi 0.5 psi
40 psi
10.5 psi 4 psi 1 psi 2 psi 3 psi 0.5 psi
30 psi
0.5 psi 3 psi 2 psi 4 psi 1 psi 0.5 psi
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Savings are real
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Pfizer pharmaceutical production unit nearby Tours (France)
Installed cooling capacity of 184,256 MBTUH (3 chillers in cascade) Total design flow: 3400 GPM Problem: production alarms! 80 TA balancing valves from STAD ½” to STAF 8” Audit of plant with TA Select based on a first measurement campaign Presettings calculated with TA Select Viscosity corrections checked with TA Select Full balancing performed using TA-Balance on one TA-CBI
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Savings are real
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Industrial plant 184,256 MBTUH cooling capacity 3900 GPM 49 psi pump head
After balancing
3400 GPM (-13%)
No production alarms!
Before balancing
39 psi pump head (-20%)
Pumping power reduction : 52 HP
Savings : 17200 €/year 24000 $/year
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