Research On Energy Efficiency Design Index For LNG Carriers

With the increasing of the energy consumption and greenhouse gas emission, the trend of global warming is getting worse. Adopting energy saving measures, formulating relevant standers and stepping into the low-carbon economy era have become the governments’ focuses of the research. Shipbuilding industry consumes a lot of fuel and produce large amounts of CO2each year, which is replaced by the clean, efficient and environmental fuel can effectively reduce the ships consumption. Liquefied Natural Gas (LNG), which has the advance of the low price and efficiency, is used as an alternative fuel of the ship, which can both save energy and reduce CO2emissions.The number of LNG carriers and LNG fuel vessels will increase quickly in the next a few years.Energy Efficiency Design Index (EEDI) has already been implemented as a mandatory standard. However, since the particularity of LNG carriers, the EEDI standard does not suitable for LNG carriers. Researching and formulating EEDI standard and reference line formula, which suitable for LNG carriers, can effectively promote the development of LNG fuel in ship industry.This paper has analyzed the characteristics of LNG carriers and established the EEDI formula and its reference line model, which based on the definition of ship EEDI formula and reference line. Then they extend to the LNG fuel vessels. The concrete research content is as follows:(1) By analyzing the characteristics of LNG carriers and introducing capacity which represents the LNG carriers’ main feature into formula, the EEDI formulas and reference line regression models of different propulsion systems have been established, which provide reference for ship design.(2) In order to verify the feasibility of the EEDI formula, there are two methods can be used to perform sensitivity analyses of the EEDI formula. Then according to the conclusion, corresponding measures for energy conservation and emissions reduction have been proposed.(3) Extending EEDI formula to LNG fuel vessels, this paper has established the EEDI formulas and reference line of electric propulsion LNG fuel vessels, which provide reference for the wide application of LNG fuel on ship. (4) In order to make the EEDI calculation quickly and simply for designers, the EEDI calculator software has been developed. Based on VB.NET platform, designers can easily calculate the EEDI value for each LNG carrier and LNG fuel vessel.LNG becomes the ship’s main fuel instead of oil, which can effectively control and reduce greenhouse gas emissions. In this paper, the research could provide a reference for the design and construction of LNG carriers and LNG fuel vessels.