SES System Efficiency Service revealed poor efficiencies
An energy efficiency analysis performed for an automotive supplier was intended to make the system conditions of a cooling lubricant supply system transparent and provide solutions for increasing profitability.
An energy efficiency analysis performed for an automotive supplier was intended to make the system conditions of a cooling lubricant supply system transparent and provide solutions for increasing profitability.
The challenge:
Sustainable increase in efficiency
Five volute casing pumps of the same design including one variable speed pump are operating in parallel to circulate cooling lubricant. Pump efficiency ranges between 58 to 65%.
The comprehensive system analysis revealed that all machines were throttled on the discharge side causing pressure losses of up to 1 bar. Despite fluctuating system loads, the speed of the variable speed pump remained constant for two thirds of the operating time. In the remaining third, the speed was reduced to such an extent that it was causing inadmissible zero-flow operation. Furthermore, pressure drops were recorded on all pumps at regular intervals, i.e. every 30 minutes. At the same time, the vibrations on pumps 1 and 2 increased significantly. This indicated that foam was being sucked in.
The solution:
Replacement of the existing pumps with speed-controlled pumps
As the customer wanted to reduce the flow rate by approx. 10%, KSB recommended replacing the existing pumps with five Etanorm 125-100-200 pumps equipped with 55 kW IE3 motors including PumpDrive variable speed systems. While only four pump sets are now running in continuous operation at a lower pressure, pump no. 5 is installed as a redundant pump set. This optimisation measure has resulted in energy savings of up to 28.5%. The suggested solution was convincing: the customer implemented the recommendations for optimisation with KSB.
Left: five Etanorm 125-100-200 pumps equipped with 55 kW IE3 motors including PumpDrive variable speed systems; right: the old pumps
The result:
Amortization of modernization after 1.6 years
Based on the results of the analysis, the pumps and the variable speed systems have been optimally designed for the required system conditions.
Operating data of the variable speed pump in the old installation; frequent zero-flow operation
Data | Facts | Figures
Application: Cooling lubricant system
Year: 2015
Duration: 1 month
- Energy costs per year before optimisation: € 146,494
- Energy costs per year using new pumps including variable speed systems: € 104,701
- Savings p.a.: € 41,793
- Costs for pumps including variable speed systems: € 65,624
- Payback period: 1.6 years
- Energy savings: 417,932 kWh
- CO2 savings: 237 t
Used products
PumpDrive R (KSB202)
Modular self-cooling frequency inverter that enables continuously variable speed control of asynchronous and synchronous reluctance motors by means of analog standard signals, a field bus or the control panel. As PumpDrive R is self-cooling, it can be mounted on the wall or in a control cabinet. Up to six pumps can be controlled without needing an additional controller. PumpDrive R extends the power range of PumpDrive 2 up to a rated power of 250 kW (standard) / 1400 kW (on request).
