ShareThis
Posted - Thursday, May 10, 2012 - Written by: Edward J. Eastlack - United States Merchant Marine Academy, Kings Point, NY as posted in The Maritime Executive
Edward J. Eastlack of USMMA wrote a powerful thesis for the Masters of Science in Marine Engineering program focusing on emissions reductions from a marine power plant and vessel efficiency standpoint.
Read the abstract below, or view the entire document here.
http://www.maritime-executive.com/files/EM681_Thesis_E_Eastlack.pdf
ABSTRACT
Rising fuel costs and increasingly stringent emission standards for the marine industry have caused ship owners to look at a wide range of marine technologies to meet environmental compliance and to reduce lifecycle costs.
Emissions can be reduced in many ways including improved fuel quality, improved plant efficiency and after treatment. With distillate fuels, residual fuels and after treatment having high cost and equipment lifecycle costs, LNG appears to be the clear choice for helping the marine industry meet these new emissions standards.
The carbon footprint of a vessel can also be reduced by improved efficiency. Optimized natural gas prime movers and electrical systems can assist in achieving these efficiency targets. The International Maritime Organization (IMO) has adopted greenhouse gas reduction measures by requiring an International Energy Efficiency Certificate (IEEC) and Ships Energy Efficiency Management Plan (SEEMP) for existing vessels and an Energy Efficiency Design Index (EEDI) for new build vessels after January 2013. Therefore, the industry must now address both emissions and plant efficiency. As a result, there is also increasing interest in fuel efficient “hybrid” propulsion/electrical systems.
The latest systems use a common prime mover that does not have to have a fixed frequency to accommodate the electrical system. Several new system designs are adopting this concept where generators are able to operate at variable speed, and all outputs go into a common DC grid or bus system. From there, the DC is converted to whatever voltage and frequency a particular load or system needs, using VFD technology to achieve improved plant efficiency or fuel economy. Hybridization of the power plant can improve the transient response of gas engines as well as provide additional load profile flexibility and reduced running hours on the prime movers which translates to improved efficiency and reduced carbon emissions.
These alternative sources of energy are easy plug and play options to the existing DC grid or bus system. There are many options for hybridization to include high powered lithium battery banks, wind turbines, solar panels, fuel cells, super capacitors and micro turbines. The Rankine Cycle using refrigerant or critical CO2 gas as the working fluid has also gained acceptance as an effective means to recover waste heat from low heat sources such as engine jacket water and exhaust gases, thus, improving plant efficiency even further.
Optimized bow, hull, propeller and rudder design are additional ways to improve efficiency and reduce carbon emissions. Gas hybrid power plants with waste heat recovery systems and optimized hydrodynamics offer ship owners the right combination of marine technologies needed to reduce fuel consumption, emissions, lifecycle costs as well as improved reliability and durability of shipboard propulsion systems.
view the entire document here.
thesis - http://www.maritime-executive.com/files/EM681_Thesis_E_Eastlack.pdf
Post found here -
http://www.maritime-executive.com/article/the-future-of-marine-propulsion-gas-hybrid-power-plants
No comments:
Post a Comment