Transcript Dias nummer 1

Grundfos FLOW THINKING
Air conditioning
the
Grundfos Way
Grundfos FLOW THINKING
Obtainable energy saving
1. Constant pressure
2. Constant diff. pressure
3. Proportional diff. pressure
100
(calculated)
4. Proportional diff. pressure
(measured)
5. Temperature control
H
Effect in %
80
1.
60
40
2.
20
3.
4.
5.
0
0
20
40
60
Flow in %
25%
100% Q
80
100
Grundfos FLOW THINKING
Optimized operation cost
Optimized operation cost often means LOWER ENERGY COST
An effective way of checking the profitability of the pump system is to
use Life Cycle Cost analysis. This will show not only the ”energy cost”
but all costs related to the pump system.
The result of the analysis can also
show the pay-back time of a
speed
con-
trolled
solution
compared to a traditional constant
speed pump.
Result of Life Cycle Cost analysis
Grundfos FLOW THINKING
Controls For Variable Speed Application
• VARIOUS OPTIONS e.g.
• Pumps with built-in Frequency Converter & PLC…
• Pumps with External Frequency Converter & External PLC…
Grundfos FLOW THINKING
Primary - Secondary Circuit With Variable Speed
Secondary Pumps
Load
2 – Way
Valve
Balancing Valve
Chillers
Common
Panel with
PLC & VFD`s
Primary Pumps
Secondary
Pumps
Air Separator
Grundfos FLOW THINKING
Why Do We Need Variable Speed
Secondary and Tertiary Pumps ???
•For Energy Saving….
•For better & smooth operation….
Grundfos FLOW THINKING
How Do We Achieve This Reduction In Power
Consumption ??
By Using Variable Frequency Drive and Logic controller
with the Secondary Pumps….
Grundfos FLOW THINKING
Basic Law which helps in achieving this – Affinity
law
1. Flow2 = Flow1(Speed2/ Speed1)
2. Head2 = Head1(Speed2/ Speed1)2
3. BKW2 = BKW1(Speed2/ Speed1)3
If Diameter of Impeller is to be trimmed then instead of
speed the same can be used in above formulas.
Grundfos FLOW THINKING
Basic Concept
Set Value
PMU
Output
4 – 20 mA
PFU
From Field
Sensor (DPT)
PFU – Pump Functional Unit
PMU – Pump Management Unit
To
VFD/Pump
Grundfos FLOW THINKING
Opening/Closing of 2- Way Valve
-Signal from the sensor, installed at load
regulates the valve opening & closing.
-This way differential across 2-way valve also
changes & accordingly output signal is given to
PLC.
Temperature Sensor
Load
Output to PFU from DPT
Grundfos FLOW THINKING
An Example
Load
Balancing Valve
DPT
Chillers
Panel with PLC &
VFD`s
Secondary
Pumps
Primary Pumps
Grundfos FLOW THINKING
APPROVAL FROM INTERNATIONAL
AGENCIES
Approval from – CE, U/L
Conforms to - Electromagnetic compatibility
(89/336/EEC) to standard EN 50 081 – 1 and EN 50
082 – 2 and Electrical equipment design 73/23/EEC
standard to EN 60 204-1.
Grundfos FLOW THINKING
Tertiary Pumping
In Air-conditioning Systems
Grundfos FLOW THINKING
Air conditioning systems
Improved balancing by Tertiary pumps
Colling tower
Heat recovery
Fan coils
Cooling ceiling
M
M
Pressure
holding
Cooling surface
M
Primary
pump
Chiller
Buffer
tank
Secondary
pumps
Grundfos FLOW THINKING
System with only secondary pumps
Air
unit
Air
unit
Fan
coils
Air
unit
Fan
coils
H
Max.
Dp
Buffer
tank
Dp: connection point
Qmax. Q
Dp
secondary
pump
Dp: pipes,
control valves
fan coils etc.
Distance/pressure profile
Air
unit
System with tertiary pumps
Air
unit
Fan
coils
Air
unit
Fan
coils
Tertiary pumps
H
M
M
M
M
M
Buffer
tank
Max.
Dp
Dp: connection point
Qmax.
Q
Dp
secondary
pump
Dp:
control valve
Distance/pressure profile
Grundfos FLOW THINKING
Air
unit
Hybrid System
Air
unit
Fan
coils
Air
unit
Fan
coils
Tertiary pumps
H
M
M
M
M
M
Buffer
tank
Max.
Dp
Dp: connection point
Qmax.
Q
Dp
secondary
pump
Dp:
control valve
Distance/pressure profile
Grundfos FLOW THINKING
Tertiary Systems….Few points
 Tertiary pumps can be Variable speed…….
 Tertiary pumps can be fixed speed also….
 Mixing loops are not mandatory in tertiary loops…
 But mixing loops add flexibility in the overall airconditioning system…
 Tertiary pumps PLC should be controlled by DPT signal
(if
variable speed panel is used)…
Grundfos FLOW THINKING
Tertiary Systems….Few points
 For Secondary pumps only friction loss upto zone
termination point should be taken care…
 For Tertiary pumps friction loss of valves, coil etc should
be taken care….
Grundfos FLOW THINKING
Advantages with Tertiary pumps
1. Smaller secondary pumps, motor and drives
2. Lower differential pressure in all connection points
3. Lower operation cost
4. Higher flexibility if the system have to be redesigned
5. Each to find the right location for the Dp sensor
6. Minimized risk of “over sizing” secondary pumps
Grundfos FLOW THINKING
Mixing Loops
In Air-conditioning Systems
Grundfos FLOW THINKING
Mixing loops
•
•
•
•
•
•
Why mixing loops
Where can mixing loops be used
Different types of mixing loops
Design
Function
Energy saving by using mixing loops
Grundfos FLOW THINKING
Why mixing loops – Increase of hydraulic balance in large/Tertiary/district
heating or cooling systems
The source of unbalance in a system
In large systems the diffential pressure will decrease/increase dependingupon
the distance from the pump, and not reflect the actual need.
Pressure
profile
Dp
Dp
Dp
Dp
Dp
Grundfos FLOW THINKING
Why mixing loops – Increase of the control of different part of a building
Systems with zone
division
Facade divided
Will adapt to
weather conditions:
Sun
Wind
Floor divided
Will adapt to use of
the building:
Holidays
Load of the floor
Grundfos FLOW THINKING
Why mixing loops – Correct differential temperature at the chiller return
High differential temperature means lower flow.
Formula for calculating the
flow in a cooling system
Dt
5oC
Dt
5oC
kW x 0,86 = m3/h
Dt
Dt
5oC
Dt
5oC
Dt
5oC
Dt
5oC
In particulary District/large cooling systems a correct differetial temperature reduces the
operation cost.
Grundfos FLOW THINKING
Why mixing loops – parameters which influence in the indoor temperature
External parameter which have
influence on the cooling/heat demand
Internal parameter which have
influence on the cooling/heat demand
Other rooms
Sun radiation
Light
Light
Wind
Electrical
equipment
People
Other rooms
Grundfos FLOW THINKING
Where can mixing loops be used
All circulating systems where there is a demand for
improving the balance and controlling the temperatures
•Heating systems
•Radiator systems
•Air handling units
•Floor heating
•Heating
systems
•District
Heating/Cooling
•Building connection
•Cooling systems
•Fan coils
•Air handling units
•Cooling ceilings
For Primary-Secondary as well as Secondary-Tertiary
Grundfos FLOW THINKING
Mixing loops overview
System 1
System 2
System 3
tO
tO
Load
tO
Load
Tertiary side
Load
tf
tf
Operation
cost
Load
tO
Load
tf
tr
tr
M
M
M
Secondary side
Hydraulic
separation
Temperature
control
Investment
System 5
tO
tf
tr
tr
M
System 4
M
NO
YES
NO
YES
YES
NO
YES
YES
YES
YES
MIDIUM
MIDIUM
HIGH
HIGH
HIGH
LOW
LOW
LOW
HIGH
HIGH
Grundfos FLOW THINKING
Design
Secondary side
Out-door
temperature sensor to
Tertiary side
Loop
controller
Flow
temperature sensor
Thermometer
Tf
Shut-off
valve
Circulator pump
Strainer
M
Non-return
valve
Control valve
Shut-off
valve
Tr
Return
temperature sensor
Grundfos FLOW THINKING
Function of the Loop controller
By adding more or less chilled water to the tertiary side the Loop Controller is
adjusting the flow temperature based on outdoor, zone supply and return
temperature.
Loop
controller
to
tf
M
tr
Grundfos FLOW THINKING
Energy consumption in system with mixing loops pumps.
Conclusion:
1. Full hydraulic balance in the system:
It will also be possible to change the cooling/heating system in one of the
buildings without
disturbing the balance in in the other buildings.
2. Reduced power consumption:
Experiences shown a reduction of chiller power consumption when mixing
loops are installed.
3. Reduced pump energy consumption:
Can be reduced to up to 30-40%
Grundfos FLOW THINKING
Energy consumption in system with mixing loops pumps.
Conclusion:
4. Better zone control:
Mixing loop will help in achieving better individual zone control.
5. Smaller Secondary pumps:
In case of Primary-secondary-tertiary systems smaller secondary pumps are
used
6. Suitable for any application:
Can be used for Primary-secondary-Tertiary, Primary-Tertiary as well as
Primarysecondary
Grundfos FLOW THINKING
THANK YOU