Deep Well Pumps - Danfossforms.danfoss.com/mc/InMotion/11/Deep Well Pumps.pdf · deep well pump. It...
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www.Danfoss.com/Drives inMotion The VLT® Newsletter No 11, Sept. 2005 Page 1/2 Danfoss VLT® 8000 Aqua Drive for Deep Well Pumps This decision did not come easily, because variable speed drives on deep well pumps are relatively new technol- ogy in the local water industry. Besides, the drives are also costly, compared to traditional control systems. Customer Statements According to Mr. Emil Puerto, Planning Manager for Laguna Water District, the project still went through, because they knew that variable speed drives when used to control the speed of pumps to meet the actual water demand, will enable Laguna Water District to save considerably on energy bill. The first VSD installation for Laguna Water is the Jubileeville Pump Station located in the town of Bay, Laguna. The pump is a 55kW, vertical turbine driven deep well pump. It is installed with a VLT 8072, IP54 drive, directly mounted on the wall. This installation confirmed the po- tential energy savings and signaled the acceptance of the VLT 8000 at Laguna Water. After this first initial installation and after the savings in energy cost was confirmed, three more Danfoss VLT 8000 were installed: at the Lamot II Pump Station, Maahas Pump Station and most recently, at the VEGA Pump Station. The VEGA Pump station is a Grundfos TM submersible deep well pump. It is in this particular pump station that the compatibility of Danfoss VLT 8000 with submersible pumps was tested. Two concerns were addressed, the relatively long motor cables because of the deep pump setting and the preconception that drives should not be used with submersible pumps. When all four pump stations were bench- marked for energy savings, the result was remarkable. Energy consumption was reduced to more than 50%. All pump stations except for Lamot II are run from generator sets. With the continuous rise of diesel fuel costs, the Danfoss VLT 8000 has proven to be a very important part of the pump stations of Laguna Water. Energy Consumption Benchmark Electricity and fuel consumption was recoreded for 30 days with he pumps running at full speed. This benchmark was then compared to the consumption for 30 days with the pumps running at variable speed. The results clearly show that Laguna Water was able to cut its diesel fuel cost by an average of 51% for the generator driven pump stations. Even the submers- ible pump at the VEGA Pump Station, initially, not considered for VSD opera- tion is recording 50% savings on fuel. The Lamot II Pump Station, which is run from the electric utility has recorded impressive savings of 56.36%. Danfoss VLT® 8000 Aqua Drive for Deep Well Pumps When the engineers of Laguna Water District were designing the control system of new pumping stations, they decided to use VLT® drives. Three-month average diesel fuel consumption of three pump stations Three-month average electricity consumption of Lamot II Pump Station
Transcript of Deep Well Pumps - Danfossforms.danfoss.com/mc/InMotion/11/Deep Well Pumps.pdf · deep well pump. It...
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inMotionThe VLT® Newsletter No 11, Sept. 2005
Page 1/2Danfoss VLT® 8000 Aqua Drive for Deep Well Pumps
This decision did not come easily, because variable speed drives on deep well pumps are relatively new technol-ogy in the local water industry. Besides, the drives are also costly, compared to traditional control systems.
Customer StatementsAccording to Mr. Emil Puerto, Planning Manager for Laguna Water District, the project still went through, because they knew that variable speed drives when used to control the speed of pumps to meet the actual water demand, will enable Laguna Water District to save
considerably on energy bill. The fi rst VSD installation for Laguna Water is the Jubileeville Pump Station located in the town of Bay, Laguna. The pump is a 55kW, vertical turbine driven deep well pump. It is installed with a VLT 8072, IP54 drive, directly mounted on the wall. This installation confi rmed the po-tential energy savings and signaled the acceptance of the VLT 8000 at Laguna Water.After this fi rst initial installation and after the savings in energy cost was confi rmed, three more Danfoss VLT 8000 were installed: at the Lamot II Pump Station, Maahas Pump Station and most recently, at the VEGA Pump Station.The VEGA Pump station is a Grundfos TM submersible deep well pump. It is in this particular pump station that the compatibility of Danfoss VLT 8000 with submersible pumps was tested. Two concerns were addressed, the relatively long motor cables because of the deep pump setting and the preconception
that drives should not be used with submersible pumps.
When all four pump stations were bench-marked for energy savings, the result was remarkable.
Energy consumption was reduced to more than 50%.
All pump stations except for Lamot II are run from generator sets. With the continuous rise of diesel fuel costs, the Danfoss VLT 8000 has proven to be a very important part of the pump stations of Laguna Water.
Energy Consumption BenchmarkElectricity and fuel consumption was recoreded for 30 days with he pumps running at full speed. This benchmark was then compared to the consumption for 30 days with the pumps running at variable speed.The results clearly show that Laguna Water was able to cut its diesel fuel cost by an average of 51% for the generator driven pump stations. Even the submers-ible pump at the VEGA Pump Station, initially, not considered for VSD opera-tion is recording 50% savings on fuel.
The Lamot II Pump Station, which is run from the electric utility has recorded impressive savings of 56.36%.
Danfoss VLT® 8000 Aqua Drive for Deep Well PumpsWhen the engineers of Laguna Water District were designing the control system of new pumping stations, they decided to use VLT® drives.
Three-month average diesel fuel consumptionof three pump stations
Three-month average electricity consumption of Lamot II Pump Station
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inMotionThe VLT® Newsletter
How electronic control save energyIn many flow applications a mechani-cal throttling device is used to limit the flow. Although this is an effective means of control it wastes mechanical and electrical energy because of high losses. As seen in the figure below, the use of electronic motor control to control flow to match the demand will result in the reduction of energy consumption.
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For centrifugal pumps, power consumed
is directly proportional to the cube of the
speed:
%P = (%rpm)3
Therefore a small reduction in pump speed
results in a large reduction in energy
consumption Even just a 20% reduction in
pump speed results in almost 50% reduc-
tion in energy consumption.
Comparison of Energy consumption
Pump speed (rpm)
Pow
er c
onsu
mp
tion
Danfoss VLT® 8000 Aqua Drive for Deep Well Pumps
Electronic control
