Marine Engineering

There are two methods to reduce NOx emissions; Primary and secondary measures.  Primary measure aim at reducing the amount of NOx formed during combustion by optimizing engine parameters with respect to emissions. As read in previous article , the  main factors influencing NOx formation  are the concentrations of oxygen and  nitrogen and the local temperature in  the combustion process. Therefore,the  primary measures focus on lowering the  concentrations, peak temperature and the  amount of time in which the combustion  gases remain at high temperatures. Miller cycle is employed in 4-stroke  engines. It uses higher than normal  pressure turbocharger. The inlet valve is  closed before the piston reaches bottom  dead center on the intake stroke. The  charge air then expands inside the engine  cylinder resulting in reduced temperature. On the other hand, secondary measures remove NOx from the exhaust ga...

During sampling continuous drip samples to be taken from the vessel manifold by means of automatic sampling device in four containers of 1 litre capacity each.  These container are to be sealed and one to be forwarded to laboratory for analysis, one to be given to the fuel supplier, one to be kept as marpol sample and one to be kept on-board. If possible new bunker not to be used till test results of the bunker analysis is received. It is important that self test is carried out in the early stages of bunkering using fuel test kit provided on board. Ignition characteristic of the oil (CCAI) should be checked to ensure that the fuel complies with ISO standard 8217.Max. Allowable values are 1. Water content at viscosity 180/380=1%2. Density at 15 C=0.9913. CCAI value=850-875 or above.If any of the results are not within the range, bunkering to be stopped and ship manager, supplier to be informed.

1.Any IC engine of cylinder diameter of 200 mm or a crankcase volume of 0.6 m3 and above shall be provide with crankcase relief valve of a suitable type with sufficient relief area. 2.In large engine, cylinder diameter more than 300mm, require one relief valve to be placed on each crankcase door. 3.In small engine, cylinder diameter not more than 300mm, crankcase door of which are usually very strong. It may have relief valve or valves at its end. 4.Its free area should not be smaller than 45cm2 and there shall be minimum of 115cm2 /m3 of the gross crankcase volume. 5.Spring setting for opening pressure is 0.07 bar at an internal pressure and will close when the pressure has been relieved. 6.The valves should open smartly and close positively and rapidly. 7. The relief valves shall be arranged or provided with means to ensure that discharge from them is so directed as to minimize the possibility of injury to personnel.

The incoming refrigerant temperature is low and chances of emerging hot spots is low. Crankcase forms the suction chamber of the compressor and chances exist that the compressor may draw in air and moisture. There is no O 2  available inside the crankcase of reefer plant which can lead to explosion.

It present the concept of an indicator for the energy efficiency of a ship It can be used to establish a consistent approach for voluntary use of an EEOI as its not mandatory. It will assist ship-owners/operators in the evaluation of the performance of their fleet with regard to CO2 emissions. Ship-owners are invited to implement either these Guidelines or an equivalent method in their environmental management systems. To provide assistance in the process of establishing a mechanism to achieve the limitation or reduction of greenhouse gas emissions from ships in operation. It present the concept of an indicator for the energy efficiency of a ship in operation, as an expression of efficiency expressed in the form of CO2 emitted per unit of transport work. These are intended to provide an example of a calculation method which could be used as an objective, performance-based approach to monitoring the efficiency of a ship’s operation. When using the EEOI as a performance indicator, the i...

Its technical measure and it aims at promoting the use of more energy efficient (less polluting) equipment and engines.  It requires a minimum energy efficiency level per capacity mile (e.g. tonne mile) for different ship type and size segments.  It became mandatory from 1 January 2013, following an initial two year phase zero when new ship design will need to meet the reference level for their ship type, the level is to be tightened incrementally every five years. The EEDI is a non-prescriptive, performance-based mechanism that leaves the choice of technologies to use in a specific ship design to the industry.  As long as the required energy efficiency level is attained, ship designers and builders are free to use the most cost-efficient solutions for the ship to comply with the regulations. The EEDI provides a specific figure for an individual ship design, expressed in grams of carbon dioxide (CO2) per ship’s capacity-mile (the smaller the EED...