Article | Helsinki | 2022-10-20
Knabstrup Vandværk, situated in Mørkøv supplies annually 52,000 m³ of water to over 500 consumers in the municipals of Knabstrup, Nøkkentved, Bakkerup, Tvede and Mørkøv Kirkeby. In addition, the waterworks supplies 73,000 m³ of water to the Nordvestsjælland Water Community that connects with 40 other waterworks in Denmark.
With ABB ACQ580 variable speed drives for water and wastewater, Knabstrup Vandværk has gained simple and energy efficient control of their pumping operations. "The result is an even pressure, which is something we really appreciate in our waterworks", says Lars Pedersen, who is the chairman of Knabstrup Vandværk and operations manager of the Nordvestsjælland Vandfællesskabet. "We are pleased when the pumps run in a stable manner without too many fluctuations. There needs to be an even flow of water and a uniform pressure that protects the pipes, joints and installations while saving energy at the same time.”
Challenges such as wear and increasing amount of energy consumption caused the board of the waterworks in 2020 to look at their aging pumps and controls in use. "We experienced an increasing number of outages at the plant and shocks in the pipes when they reconnected. This was not a sustainable solution for our operations", explains Lars Pedersen who talks about how pressure shocks wear out pipes, bends and tapping clamps, and how they can loosen ocher which ends up in the water taps of the consumers.
Ensuring the right flow of water
Lars Pedersen contacted the vendor AD Control situated in Slagelse, which supplies complete systems to manage, monitor and control water supply. After a review of the installations at the waterworks, and a desire to future-proof their capacity, the vendor suggested to take ACQ580 drives in use for five of their water pumps. "The pumps run optimally at 44 to 46 Hz, which has a direct effect on energy consumption. By using drives together with the pumps the energy consumption has decreased by 20% while the pressure is gentle on the pipes and the valves. “This means less maintenance and a longer lifespan for the water assets", according to Pedersen. The ACQ580 drives include several types of parameters that are easy to set up without the need of programming the PLC. The basic setup can be done on site in minutes using either a mobile phone or tablet to transfer data to the drive via a Bluetooth connection.
Peter Christensen who is the director at AD Control says that the intelligence lies inside the drives. "Each of the five drives control a pump which together deliver 55 m³ of water per hour at constant pressure. If, for example, the master pump reaches its maximum capacity, the control automatically starts one of the other pumps. This is made possible with the built-in function in the drive called multi-pump control. The fieldbus connection is responsible for the communication between the drives. It ensures optimal alternation of pump changes to balance the running hours and extend the lifetime of the pumps. The installation of the drives was carried out by the local partner El-huset situated in Jyderup.