How can a series of pumps be networked, cascaded and controlled – as a function of the demand – in an energy-efficient way?
A water consumer is to be supplied with water from four pumps as a function of the actual demand. The pumps are to be evenly utilized by switching in and switching out the pumps taking into account the pump operating times. The flow rate of a pump taken out of service for maintenance is to be automatically handled by a pump with free capacity.
In addition to this automatic operation, each pump should also be able to be manually operated. The drives should increase the efficiency of the system, i.e. using energy-efficient drive technology, the energy-saving potential is to be boosted up to 60%.
The use of a pump cascade increases the availability of the system and simplifies maintenance work. The base load control can be realized at a favorable price using SIRIUS switching devices. Using SINAMICS converters, demand-dependent differential closed-loop control can be implemented to achieve even and consistent flow rates. When compared to mechanical controls, the use of continually controllable converters can slash energy costs by 60% by adjusting the flow rate in-line with the actual demand.
Energy-saving motors with efficiency class IE2 or IE3 form the basis for an energy-efficient solution.