Frequency Conversion Devices: Energy Savings and Their Efficiency
Frequency conversion devices are becoming increasingly popular due to their ability to provide significant savings in electrical energy. It is essential to conduct a thorough analysis of the chosen equipment to ensure the achievement of expected energy savings results. The characteristics of the system significantly impact the degree of potential savings.
Application of Frequency Converters
Frequency conversion devices have already demonstrated their effectiveness in many industries where it is possible to reduce the speed of electric motors to save energy. In particular, in cases where devices with variable torque are used, such as centrifugal pump installations or ventilation electric motors, reducing the speed can lead to significant energy savings. This is related to the fact that energy consumption decreases according to the cubic function of the speed of the unit.
Modernization of Existing Systems
When modernizing existing buildings, it is especially important to carefully evaluate the existing units. It is necessary to ensure that the frequency conversion device can function effectively in systems with a stable speed and mechanical limiters that regulate the water flow to heating elements. In such cases, significant changes in the system may be required.
Dismantling Mechanical Limiters
Many pump units and ventilation installations consume energy significantly due to mechanical means such as dampers, blades, or valves. These mechanical limiters usually need to be dismantled before installing the frequency converter.
Flow Control and Use of Sensors
If the mechanical flow limiting is controlled automatically, there may already be a sensor necessary for the operation of the frequency converter. For example, an existing pressure sensor can be used to adjust the frequency converter's speed instead of changing old dampers, blades, or valves. The energy savings achieved from switching to a frequency converter may be less compared to replacing an old fan with stable speed that uses a mechanical damper to adjust the airflow.
Smart Use of Frequency Converters
There are numerous opportunities for using frequency converters for energy savings when used correctly. However, it is not advisable to simply install a converter on a starter and hope for reduced energy consumption. The operational efficiency must be carefully thought out and implemented.