NYK to research power saving devices for use on 50 bulk carriers
Japan NYK Line is undertaking a new research collaboration to verify the synergistic effects of power saving devices often used in conjunction with a ship’s propeller to reduce water flow turbulence. Together with Nakashima Propeller Co. and Fluid Techno Co., they said it will be the first research of its kind to seek an optimal combination of multiple energy-saving devices.
Efforts to develop modern energy-saving devices began about 50 years ago when the shipping industry responded to the first energy crisis. Various technologies have been proposed over the years, but according to NYK, most testing has focused on verification of individual devices by the marine equipment manufacturer.
Working with the propeller manufacturer and a ship design company that uses fluid analysis technology, they will verify the effects of power-saving devices that improve ship fuel efficiency by improving airflow. water generated at the stern of ships. NYK emphasizes that energy can be saved by decreasing wave resistance and water flow turbulence and research will identify the most effective devices to achieve these goals.
Examples of Energy Saving Devices (NYK)
Based on the results of their research, they plan to select the optimal combination of energy saving devices. NYK plans to install energy-saving devices on approximately 50 dry bulk carriers over the next three years.
“This business alliance can be seen as a pioneering attempt in the marine industry, in which three companies will jointly work on the best combination of multiple energy-saving devices using each company’s knowledge and strengths. initiative, a 1-8% improvement in energy efficiency and a reduction in GHG emissions from ships are expected,” NYK said in announcing the initiative.
One of the best known technologies is the Grim paddle wheel which dates from the 1970s and has been fitted to many ships. For example, SIEM Ship Management installed the system on one of its car carriers. They reported that the Siem Curiebuilt in 2009 and 43,810 dwt, saves 5 to 10% by being fitted with the Grim paddle wheel.
Sinister impeller installed on SIEM car carrier (SIEM)
SIEM explains that the Grim paddle wheel is located immediately behind the propeller. The blades of the paddle wheel have turbine profiles in this internal section while they have propeller profiles at the external section of the blades. In the turbine section, kinetic energy is taken from the propeller slipstream, which is directly transformed back into the propeller section into additional thrust. The main function of the paddle wheel is to extract energy from the propeller slipstream in the turbine part and convert this energy into additional thrust in the propeller part.
In 2015, a joint industrial project between Hyundai Heavy Industries and DNV took a fresh look at the Grim paddle wheel. They confirmed its ability to reduce the power required by 5-10%, indicating that used independently, it exceeds the fuel savings that can be expected from almost any other energy efficient device.
NYK plans to expand the research to examine the use of multiple technologies to find the best combination to save energy by improving the fluid dynamics around the stern of their vessels.