PROJECT DESCRIPTION
BACKGROUND
Countries are facing significant environmental challenges due to climate change. The UNs Intergovernmental Panel on Climate Change has concluded that climate change is generated by manmade greenhouse gases (GHG) and innovative solutions must be found to limit their impact. All economic sectors have a role to play, including the European fisheries sector that generates GHG emissions due to its fishing fleet being largely run on diesel engines. Interest in the heat recovery technology Organic Rankine Cycle (ORC) has grown in recent years and is being applied to a range of heavy industries and biomass production centres with high power rates.
OBJECTIVES
The LIFE+ EfficientShip project planned to demonstrate the efficiency of an innovative technology for reducing by 5 to 10% the GHG emissions of thermal engines with power rates from 300kW to 2MW. This aim would be achieved by adapting ORC technology, which converts heat into work, and applying it to mobile thermal engines in fishing vessels. The project aimed to demonstrate the first ORC module adapted to mobile engines, working with power rates under 1MW.
The technology would be installed on an Irish fishing boat and tested over seven months. The demonstration phase was expected to reduce fuel consumption of the vessel by 5-10%, with an expected saving of around 50 000 litres of fuel.
RESULTS
The ORC system was installed on the Mfv Orizzonte, a 22m-long trawler equipped with a propulsion engine that had a maximum power of 400 kW, along with a 56 kW auxiliary engine for the production of electricity on board. The system was connected to the engine exhaust via a three-way valve serving as a bypass for the hot loop. The bypass, located at the evaporator exchanger, allows the system to control the amount of heat that enters the ORC system and, if necessary, disconnect the engines ORC system. Seawater is used for cooling via a loop controlled by a pump.
The impact of the installed technology was monitored over 122 days. In fishing mode, the ORC turbine produced between 4 to 6 kW of power, averaging 4.8 kW that is sufficient to cover half of the boat's electricity needs. Considering all the modes (fishing and navigation), ORC turbine power generation can be said to meet around a third of the vessel's total electricity demand.
The project also calculated that the technology lowered fuel consumption by just over 1% during the demonstration, lower than the 5% target. However, the project team estimate that savings of 3% are possible by reducing the amount of the energy consumed by the ORCitself and also through greater optimisation of the genset. The percentage of electricity offered by the ORC did not lead to the same percentage of energy saving by the genset, notably due to it being oversized. Over the demonstration period of 19 trips amounting to 238 hours, the average reduction of the genset fuel consumption was 0.5 l/hour, leading to an overall reduction of GHG emissions of around 860 kg-eq CO2.
The project team will continue to refine the prototype to provide an off-the-shelf solution that can be fitted in a vessel during its annual overhaul at a local boatyard. The efficiency of the system could be further improved, with an estimated 5% reduction of fuel consumption. Moreover, installing the technology would yield a return on investment in less than four years.
On the short term, the team expects to install ORC equipment on merchant vessels. Installing ORC equipment on such ships is easier (less space constraints) and the time for return on investment is expected to be lower than on fishing vessels. As a large number of these vessels are expected to require significant refurbishing in the coming years, there is a big opportunity that opens for this technology.
Further information on the project can be found in the project's layman report and After-LIFE Communication Plan (see "Read more" section).
