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Air conditioning the Grundfos Way. Obtainable energy saving. 1. Constant pressure 2. Constant diff. pressure 3. Proportional diff. pressure (calculated) 4. Proportional diff. pressure (measured) 5. Temperature control. 100 80 60 40 20 0. 1. Effect in %. 2. 3. 4. H. 5.
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Air conditioning the Grundfos Way
Obtainable energy saving 1. Constant pressure 2. Constant diff. pressure 3. Proportional diff. pressure (calculated) 4. Proportional diff. pressure (measured) 5. Temperature control 100 80 60 40 20 0 1. Effect in % 2. 3. 4. H 5. 0 20 40 60 80 100 Flow in % 25% 100% Q
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
VARIOUS OPTIONS e.g. Pumps with built-in Frequency Converter & PLC… Pumps with External Frequency Converter & External PLC… Controls For Variable Speed Application
Primary - Secondary Circuit With Variable Speed Secondary Pumps Load Balancing Valve 2 – Way Valve Chillers Panel with PLC & VFD`s Secondary Pumps Common Air -Separator Primary Pumps
Why Do We Need Variable Speed Secondary and Tertiary Pumps ??? • For Energy Saving…. • For better & smooth operation….
How Do We Achieve This Reduction In Power Consumption ?? By Using Variable Frequency Drive and Logic controller with the Secondary Pumps….
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.
Basic Concept Set Value PMU Output To VFD/Pump 4 – 20 mA PFU From Field Sensor (DPT) PFU – Pump Functional Unit PMU – Pump Management Unit
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
An Example Load Balancing Valve DPT Chillers Panel with PLC & VFD`s Secondary Pumps Common Primary Pumps
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.
Cooling ceiling Colling tower Heat recovery Fan coils M M Pressure holding M Cooling surface Buffer tank Primary pump Chiller Secondary pumps Air conditioning systems Improved balancing by Tertiary pumps
H Max. Dp Q Qmax. Buffer tank Buffer tank H M M M M M Max. Dp Q Qmax. System with only secondary pumps Air unit Air unit Fan coils Air unit Fan coils Dp: connection point Dp secondary pump Dp: pipes, control valves fan coils etc. Distance/pressure profile System with tertiary pumps Air unit Air unit Fan coils Air unit Fan coils Tertiary pumps Dp: connection point Dp secondary pump Dp: control valve Distance/pressure profile
Hybrid System Air unit Air unit Fan coils Air unit Fan coils Tertiary pumps Buffer tank Dp: connection point Dp secondary pump Dp: control valve H Distance/pressure profile M M M M M Max. Dp Q Qmax.
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 air-conditioning system… • Tertiary pumps PLC should be controlled by DPT signal (if variable speed panel is used)…
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….
Advantages with Tertiary pumps • Smaller secondary pumps, motor and drives • Lower differential pressure in all connection points • Lower operation cost • Higher flexibility if the system have to be redesigned • Each to find the right location for the Dp sensor • Minimized risk of “over sizing” secondary pumps
Mixing loops • Why mixing loops • Where can mixing loops be used • Different types of mixing loops • Design • Function • Energy saving by using mixing loops
Why mixing loops – Increase of hydraulic balance in large/Tertiary/district heating or cooling systems Pressure profile Dp Dp Dp Dp Dp 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.
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
Why mixing loops – Correct differential temperature at the chiller return = m3/h kW x 0,86 Dt High differential temperature means lower flow. Formula for calculating the flow in a cooling system Dt 5oC Dt 5oC Dt 5oC Dt 5oC Dt 5oC Dt 5oC In particulary District/large cooling systems a correct differetial temperature reduces the operation cost.
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 People Electrical equipment Wind Other rooms
Where can mixing loops be used • Heating systems 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 • District Heating/Cooling • Building connection • Cooling systems • Fan coils • Air handling units • Cooling ceilings For Primary-Secondary as well as Secondary-Tertiary
Mixing loops overview Load M M M M System 1 System 2 System 3 System 4 System 5 tO tO tO tO tO Load Load Load Load Tertiary side tf tf tf tf tr tr tr tr M Secondary side Hydraulic separation NO YES NO YES YES Temperature control NO YES YES YES YES Investment MIDIUM MIDIUM HIGH HIGH HIGH Operation cost LOW LOW LOW HIGH HIGH
Design Loop controller Tf Tr M Secondary side Tertiary side Out-door temperature sensor to Flow temperature sensor Thermometer Circulator pump Shut-off valve Strainer Shut-off valve Non-return valve Return temperature sensor Control valve
Function of the Loop controller t to Loop controller tr tf M 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.
Energy consumption in system with mixing loops pumps. 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% Conclusion:
Energy consumption in system with mixing loops pumps. 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 Primary- secondary Conclusion: