Variable Frequency Drives Are Worthwhile

Your Ship Has VFDs? Good, But How Are They Controlled?

Using variable frequency drives (VFD) on pumps and fans is an excellent way to reduce your electrical power consumption and cut your GHG emissions. We know for example that reducing a ship’s speed by just 20% will lower its power consumption by 50% and, when its speed is slowed to 50%, the amount of energy consumed will drop to only 13%.

These devices are installed on many new ships but, in several instances, they are not optimized. Sometimes the control logic is deficient which forces engineers to operate the VFDs in manual mode in order to prevent a more perilous situation from arising.

Automatically controlling a system is the best way to avoid human error, improve systems performance, reduce fuel consumption, and cut GHG emissions.

Adjusting controls and/or developing control logics adapted to the needs of the ship must often be done during the course of routine operations. One discovers that the originally installed system does not respond fast enough, that it does not take into account special situations or that it is simply inadequate.

A good control system must respond to all the ship’s needs and adapt to all situations.

The importance of using a good control logic lies in the fact that a ship has several different operating modes. It can be at sea, in port or at anchor. It can be in the process of being loaded or unloaded. It can be operating in warm or cold weather, etc. All of the components that support the ship’s different processes are called into action in different ways and provide opportunities to achieve fuel savings.

To properly control of your VFDs, it is imperative that the systems connected to it respond according to the needs of the machinery.

If the ship has a distributed control system (DCS), changes can easily be made. If the ship does not have such a system, adding a PLC with an HMI touch screen interface can be developed by GHGES and installed according to your needs and those of your operators.

In this day and age, using pumps or fans running at full speed during the whole season is unnecessary when their speed can be varied according to the ship’s operating mode. The savings thus realized can very often cover the installation costs in less than a year.

For more details and assistance regarding your controls,  how to optimize your processes and find solutions for reducing your GHG emission, please contact us.