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Intelligent control for flow variations
22
Applications
WORLD PUMPS
May 2013
Water & wastewater
Intelligent control for flow variations A pumping station in Sweden had to cope with major seasonal flow fluctuations requiring an oversized, and energy hungry, pump to prevent flooding. The challenge for Xylem was to install a system that could handle these severe variations in flow more efficiently. The company demonstrated that it successfully reduced the energy consumption by 50%.
L
ocated in central Sweden, Dalarna wastewater pumping station was built in the early 1970s and serves approximately 450 households. The wastewater pumping station had a Flygt pump NP3102 MT 464 as well as a second pump with a premium efficiency motor. The station connects to a 300 m-long pipe, pumping wastewater from one side of a lake to the other. Melting snow, as well as heavy rainfall during spring, dramatically increases the inflow to the station. To prevent flooding, oversized pumps were installed that consumed more energy than necessary when running at normal speed. Xylem was challenged with the task of installing a system that could handle the severe variations in flow more efficiently. Xylem’s Flygt Experior system, including the Flygt SmartRun control and a Flygt N-pump were installed at the station in July 2012. Flygt SmartRun is one of the three components of Flygt Experior which combines the latest hydraulics, high efficiency motors and intelligent controls for reliable, efficient and simple working. Flygt SmartRun is designed to always search for a duty point which minimises the friction losses and maximises the efficiency of the pump system. This makes it suitable for use in a pump station where the inflow varies considerably and friction losses are high. Optimised to achieve energy savings and maximum cleaning within wastewater pumping stations, Flygt SmartRun capitalises on the benefits of variable speed pumping. A key feature is the patented energy minimiser function which reduces energy consumption compared to conventional on/ off systems.
www.worldpumps.com
Xylem measured energy consumption at the Dalarna station before and after the new equipment was installed. Full scale tests have revealed that the new solution decreased energy consumption at the station by almost 50%.
"The Flygt SmartRun pipe cleaning cycle flushes the pipe system to minimise sedimentation. " As part of the upgrade to the Dalarna wastewater pump station, a data logger was connected to Flygt SmartRun via a Modbus fieldbus. As such, operational information such as level in the sump, the electric current
absorbed by the motor, the amount of energy consumed, the working frequency and any alarms raised could be transmitted to a central server. Using a simple browser on PC, Smartphone or Tablet, the operator can view all of this data, adjust parameters and manage alarms. Pre-programmed functions such as pump, sump and pipe cleaning can help to cut maintenance costs by reducing grease deposits on pumps and the sump wall which can commonly build up in wastewater pump stations. With the Flygt SmartRun sump cleaning sequence, the pump overrides the stop level to pump down to snoring level to remove oil, grease and other floating pollutants from the surface. This means there is no need to shut the pump down for manual
Dalarna pump station in Sweden connects to a 300 m-long pipe, pumping wastewater from one side of a lake to the other.
WORLD PUMPS
Applications May 2013
Sigtuna station. A key feature is the patented energy minimiser function which reduces energy consumption compared to conventional on/off systems. It combines the simplicity of conventional on/off control with the advanced functionality of a variable frequency drive (VFD). With Flygt SmartRun, impeller speed is steadily secured to the minimal energy level without the use of a flow meter or any other external measurement equipment.
Efficiency gains
Flygt SmartRun at the Sigtuna pumping station. The control system capitalises on the benefits of variable speed pumping.
cleaning and the system can be monitored more accurately. With conventional variable frequency drives another concern is that flow velocity in the pipes becomes too low, resulting in sedimentation of solids in the pipes. The Flygt SmartRun pipe cleaning cycle flushes the pipe system to minimise sedimentation.
Sigtuna pumping station At another pump station in Sigtuna. located in the Sigtuna Municipality, Stockholm County, Sweden, Xylem successfully reduced the energy consumption of the station by
30%. Built in 2006 the Sigtuna station has an inflow of approximately 65,000m3 annually and has two Flygt N-3153 HT pumps, originally started via soft starters. There are generally two types of controls for wastewater pumping systems. Conventional on/off controls, which are simple to use but provide limited opportunities to optimise functionality; and variable frequency drives (VFD) which provide more fine-tuning possibilities but can be complicated to install and difficult to optimise. In 2011, Xylem installed Flygt SmartRun pump controller on each pump in the
A measure of pump station efficiency is the amount of energy required to transport a specific volume of fluid, specific energy kWh/m 3. With this in mind, reducing frequency via the VFD also results in lower friction losses which can achieve considerable energy savings. To prove the point, Sigtuna put its installation to the test. Specific energy was calculated by measuring consumed energy and pumped liquid volume between specific points in time, before the installation of Flygt SmartRun and after, and then projected for a year’s consumption. Average specific energy before and after the installation has been determined to 0,113 kWh/m3 and 0,079 kWh/m3 respectively, which represents a saving of 30%. During this time, Flygt SmartRun self-adjusted down to a minimum frequency of 37Hz. www.xyleminc.com
www.worldpumps.com
23
Applications
WORLD PUMPS
May 2013
Water & wastewater
Intelligent control for flow variations A pumping station in Sweden had to cope with major seasonal flow fluctuations requiring an oversized, and energy hungry, pump to prevent flooding. The challenge for Xylem was to install a system that could handle these severe variations in flow more efficiently. The company demonstrated that it successfully reduced the energy consumption by 50%.
L
ocated in central Sweden, Dalarna wastewater pumping station was built in the early 1970s and serves approximately 450 households. The wastewater pumping station had a Flygt pump NP3102 MT 464 as well as a second pump with a premium efficiency motor. The station connects to a 300 m-long pipe, pumping wastewater from one side of a lake to the other. Melting snow, as well as heavy rainfall during spring, dramatically increases the inflow to the station. To prevent flooding, oversized pumps were installed that consumed more energy than necessary when running at normal speed. Xylem was challenged with the task of installing a system that could handle the severe variations in flow more efficiently. Xylem’s Flygt Experior system, including the Flygt SmartRun control and a Flygt N-pump were installed at the station in July 2012. Flygt SmartRun is one of the three components of Flygt Experior which combines the latest hydraulics, high efficiency motors and intelligent controls for reliable, efficient and simple working. Flygt SmartRun is designed to always search for a duty point which minimises the friction losses and maximises the efficiency of the pump system. This makes it suitable for use in a pump station where the inflow varies considerably and friction losses are high. Optimised to achieve energy savings and maximum cleaning within wastewater pumping stations, Flygt SmartRun capitalises on the benefits of variable speed pumping. A key feature is the patented energy minimiser function which reduces energy consumption compared to conventional on/ off systems.
www.worldpumps.com
Xylem measured energy consumption at the Dalarna station before and after the new equipment was installed. Full scale tests have revealed that the new solution decreased energy consumption at the station by almost 50%.
"The Flygt SmartRun pipe cleaning cycle flushes the pipe system to minimise sedimentation. " As part of the upgrade to the Dalarna wastewater pump station, a data logger was connected to Flygt SmartRun via a Modbus fieldbus. As such, operational information such as level in the sump, the electric current
absorbed by the motor, the amount of energy consumed, the working frequency and any alarms raised could be transmitted to a central server. Using a simple browser on PC, Smartphone or Tablet, the operator can view all of this data, adjust parameters and manage alarms. Pre-programmed functions such as pump, sump and pipe cleaning can help to cut maintenance costs by reducing grease deposits on pumps and the sump wall which can commonly build up in wastewater pump stations. With the Flygt SmartRun sump cleaning sequence, the pump overrides the stop level to pump down to snoring level to remove oil, grease and other floating pollutants from the surface. This means there is no need to shut the pump down for manual
Dalarna pump station in Sweden connects to a 300 m-long pipe, pumping wastewater from one side of a lake to the other.
WORLD PUMPS
Applications May 2013
Sigtuna station. A key feature is the patented energy minimiser function which reduces energy consumption compared to conventional on/off systems. It combines the simplicity of conventional on/off control with the advanced functionality of a variable frequency drive (VFD). With Flygt SmartRun, impeller speed is steadily secured to the minimal energy level without the use of a flow meter or any other external measurement equipment.
Efficiency gains
Flygt SmartRun at the Sigtuna pumping station. The control system capitalises on the benefits of variable speed pumping.
cleaning and the system can be monitored more accurately. With conventional variable frequency drives another concern is that flow velocity in the pipes becomes too low, resulting in sedimentation of solids in the pipes. The Flygt SmartRun pipe cleaning cycle flushes the pipe system to minimise sedimentation.
Sigtuna pumping station At another pump station in Sigtuna. located in the Sigtuna Municipality, Stockholm County, Sweden, Xylem successfully reduced the energy consumption of the station by
30%. Built in 2006 the Sigtuna station has an inflow of approximately 65,000m3 annually and has two Flygt N-3153 HT pumps, originally started via soft starters. There are generally two types of controls for wastewater pumping systems. Conventional on/off controls, which are simple to use but provide limited opportunities to optimise functionality; and variable frequency drives (VFD) which provide more fine-tuning possibilities but can be complicated to install and difficult to optimise. In 2011, Xylem installed Flygt SmartRun pump controller on each pump in the
A measure of pump station efficiency is the amount of energy required to transport a specific volume of fluid, specific energy kWh/m 3. With this in mind, reducing frequency via the VFD also results in lower friction losses which can achieve considerable energy savings. To prove the point, Sigtuna put its installation to the test. Specific energy was calculated by measuring consumed energy and pumped liquid volume between specific points in time, before the installation of Flygt SmartRun and after, and then projected for a year’s consumption. Average specific energy before and after the installation has been determined to 0,113 kWh/m3 and 0,079 kWh/m3 respectively, which represents a saving of 30%. During this time, Flygt SmartRun self-adjusted down to a minimum frequency of 37Hz. www.xyleminc.com
www.worldpumps.com
23