In a hydraulic system there are many parts that can be potential energy thieves. But we can help find these and come up with the right solution to minimize energy use and optimize efficiency. With today’s high energy prices and environmental requirements, the return-of-investment for these kind of projects can be very short.
There are many different types of hydraulic pumps and each has its advantages and disadvantages. A variable displacement piston pump is, for example, very common in press applications. It is relatively efficient and is good at regulating the flow and thus positioning different movements. But the pump is most efficient at high displacements (angle). So in a multi-pump system, it can save energy to have fewer pumps work at a higher displacement instead of having all pumps work in parallel.
Accumulators are used in various ways in hydraulic systems. By replacing several larger motors with a slightly smaller one that can drive a pump that charges an accumulator for a longer period of time, the installed power can be significantly reduced. Properly set up, accumulator systems can add high performance to hydraulic functions. However, if set up incorrectly, these systems can be major energy wasters.
Variable frequency control
One way to ensure that the pumps work with optimal efficiency is to control the speed of the electric motor with a frequency converter (VFD, Variable Frequency Drive). Through the correct control in the PLC, it is ensured that the displacement of the pump and the speed of the motor work together for optimal efficiency and performance. We have installed frequency converters for motors of up to 250 kW to hydraulic systems for extrusion presses and we are happy to help with calculations of potential energy savings. Another advantage of frequency controlling the pump motors is that it is possible to raise the speed and thus possibly lower the dead cycle on the press. Where possible, the repayment period will be even shorter.