Japanese shipping major NYK Line has conducted a demonstration test of new technology Hz Navi System, which can produce energy-saving effects by lowering the frequency of the generator according to optimal specifications.
As informed, the tests were carried out in cooperation with Japanese partners MTI Co., Oshima Shipbuilding, Terasaki Electric and Daihatsu Diesel MFG.
The technology was installed on NYK-operated bulk carrier White Princes from April 2023 to April 2024. The ship has a length of 209.9 meters, a width of 37 meters, and a deadweight tonnage of 60,343 tons. It was built in 2022.
Hz Navi is a system that allows generator frequencies to be adjusted according to shipboard conditions within the range specified by ship classification rules, thereby reducing the fuel consumption of generators.
This system utilizes a technology jointly patented by NYK and Tsuneishi Shipbuilding called “generator frequency control technology”, which allows the generator frequency to be switched between the regular frequency and a lower energy-saving frequency.
In the demonstration test, fuel consumption was measured and a safety evaluation was conducted with the Hz Navi mode (approx. 57 Hz) activated.
According to NYK, an energy-saving effect of approximately 10% was confirmed for the generator. No abnormalities were observed during the demonstration test, and it was confirmed that the vessel could be safely navigated.
Current generator frequencies are set so that onboard equipment such as pumps and motors, which operate in conjunction with the power supply frequency, can perform adequately even under the worst possible conditions, and operating at the normal frequency during normal navigation consumes extra power.
Therefore, there was a need to develop a system that could reduce fuel consumption and quantity by lowering the frequency of generators to best match optimal specifications, NYK highlighted.