As world trade grows, fuel prices increase, and International Maritime Organization (IMO) emissions requirements tighten, there is more demand for the marine industry to employ innovative means of reducing the fuel consumption and emissions of shipping vessels.
The main engines of large shipping vessels produce a large quantity of low temperature heat, but this valuable heat energy is transferred to cooling systems and rejected to the oceans as waste. At the same time, the electrical needs of shipping vessels are sustained by burning diesel fuel to run generators.
Calnetix Technologies, in partnership with Mitsubishi Heavy Industries, has developed the Hydrocurrent™ 125EJW Organic Rankine Cycle (ORC), a modularized system capable of absorbing the waste heat of main engine jacket water and converting it into grid-quality electric power. By combining this renewable source with the existing non-renewable source (engine gensets) a unique renewable-non-renewable hybrid power system is realized with minimal changes to overall ship power train. This novel hybrid system can be applied to all new and existing ships and allow for further integration into ship systems with available waste heat.
Shipping vessels such as tankers, bulk carriers, and container vessels are typically equipped with a category 3 marine diesel engine for main propulsion. A 30 MW engine, a most common engine size, utilizes 200–300 m3/hr of jacket water regulated to a heated temperature of 80–95 C. When integrated into the jacket water and sea water loops, the ORC can produce up to 125 kW of gross grid-quality electric power. This adds an immense benefit to the ship. To produce the same amount of power, a diesel generator consumes as much as 250 metric tons of diesel fuel per year, generates emissions, and requires significant maintenance.
Calnetix Technologies has leveraged its core technologies to develop the ORC into a reliable, high efficiency, compact and modular design. The turbo-generator or Integrated Power Module (IPM) is a hermetically sealed, high speed radial turbine coupled to a permanent magnet generator supported by magnetic bearings. Power from the IPM is converted by a high efficiency power converter supplying the ship with reliable power. The integrated design of the ORC along with the sophistication of its controls systems ensures essential ship functions are undisturbed under all conditions. The ORC is designed to comply with Nippon Kaiji Kyokai and Lloyd’s Register marine regulations and sea trials are anticipated to take place in 2015.