# Fuel oil formula

In ship’s engine room, several gauging devices show different crucial parameters such as for example level, pressure, temperature an such like. But there are several crucial parameters which cannot be read directly through any instrument because they depend on a number of powerful elements.

This needs the marine professional working onboard ships to do some formula based computations by deciding on all those factors with feasible available inputs. Of all of the important computations that are is done on-board ships, there several ones which marine engineers must know unfailingly.

Following are 3 essential variables which are most frequently necessary to be computed by marine engineers for record maintaining:

**1. Bunker Calculation:**

Bunker terms to fuel oil in maritime industry. Bunker volume calculation is the most important calculation which every marine engineer must be familiar with throughout his career. Bunker gasoline, being a top appreciated item, has got to be meticulously and precisely determined for deciding the quantity.

The quantity of definite volume of bunker increases with increase in heat whereas its body weight continues to be the exact same. For this reason, bunker is definitely bought and measured in body weight rather than by volume.

In addition all the power and effectiveness calculations of gas aboard ships are calculated with regards to size regarding the gas without its amount. (Calculation of bunker gas amount in body weight requires many aspects to be considered making it more complicated.)

Said under could be the means of measuring and determining the bunker amount:

-> after the total quantity (tonnes) of bunker gasoline to-be received is confirmed, take sounding of ship’s bunker tanks & determine the offered number of gasoline oil onboard to formulate a bunkering plan denoting how much tonnes of gasoline become bunkered on each container & the tank series of bunkering.

-> Before commencing of bunker operations, confirm the heat at which the bunker is to be obtained and make a note of the conventional density for the gas oil. With this parameters calculate the quantity of bunker become gotten in each tank as per bunkering plan and make a note of the last sounding standard of each container after bunkering operating capacity table the easier preventing & change-over to next container.

The basic formula employed for determining the bunker amount in body weight is:

Mass = Amount x Density

-> its becoming mentioned that inside above formula, the thickness and amount of bunker fuel ought to be known at same temperature.

-> After getting the bunker, simply take sounding/ullage of all of the bunker tanks utilizing sounding tape and note down the tank temperature. Utilize sounding paste in tape while measuring distillate gasoline such MDO for simple reading.

-> Ship constantly does not float with even keel and so the floating conditions regarding the ship particularly trim and listing should-be well-noted while taking the sounding of bunker tanks.

-> Every ship receives a tank capability table which each tank capacity in amount is marked resistant to the successive quantities of sounding/ullage with correction aspects under different trim and heel circumstances associated with the ship. The amount of gasoline oil at tank heat the matching container sounding is thus calculated making use of tank capacity table, which provides the particular sounded amount.

-> The density of gas oil (in kg/m3) at standard research heat of 15⁰C is obviously supplied by the provider in Bunker shipping Note. With this specific the density of fuel oil at tank temperature can be determined making use of ASTM dining table or using computer software most commonly set up on all ship’s computer.

The formula regularly determine the Temperature Corrected Density is:

= (Density of Fuel Oil @ 15⁰C) x [1- {(T-15) x 0.00064}]

Where:

T = heat of oil in bunker tanks in degree celcius,

0.00064 = Correction aspect

Considering that the bunker oil is normally provided into vessel at temperature greater then 15⁰C, the formula used for calculating the bunker volume in weight will be-

Metric Tonnes = (Actual Sounder Amount) X (Heat Corrected Density)

-> The matching values of each and every tank are tabulated for easy reading as well as the total weight of bunker quantity is determined.

**2.** Specific Fuel Oil Intake (SFOC):

Particular fuel oil consumption could be the way of measuring size of fuel consumed per product time for you to create per KW. The marine engine performance is generally determined using the SFOC.

To have accuracy, the gas usage and power developed **is definitely** calculated over a suitable time period on a good weather condition. The formula utilized for calculating SFOC is:

**SFOC (g/kwh) = Mass of fuel consumed each hour / Power created in KW**

-> The readings of flow meter to primary engine must be noted within the specified time-interval state one hour. Aided by the difference in readings the amount of gas consumed is acquired. It can also be measured by noting along the HFO service tank reading provided the oil has been supplied and then top engine.

-> The mass of observed number of gas eaten is determined by following the above-said bunker calculation process.

-> The horse-power can be calculated utilizing dynamometer if fitted from the shaft regarding the engine that'll indicate the BHP in electronic indicator. If you don't, the hp could be computed utilizing engine rpm and average pump gas list using motor characteristic bend of varied sea studies that will be supplied by producer. But the calorific value of the fuel used for sea trial may differ and hence payment aspect must be determined to get the accuracy in calculation.

3. Percentage of slide:

Slip is recognized as the essential difference between the rate of this engine and actual rate regarding the ship. It is always computed in percentage. Positive slide is impacted by numerous reasons such as fouled bottom or hull part which offers resistance toward motion of ship, ecological facets particularly water current and wind against the ship direction. Slide is unfavorable in the event that ship rate is influenced by after water or wind. Motor slide is determined daily onboard the vessel and recorded in log-book.

Engine distance – noticed distance

Portion of Slip = ————————————————– X 100%

Motor length

- The actual length (nautical mile) covered by the ship from noon to noon is assessed using ship’s log.

- The total revolutions associated with the propeller from noon to noon is gotten using transformation countertop. The engine distance may be determined utilising the pitch associated with propeller provided by the manufacturer. Care should be taken in product transformation of pitch from meter to nautical mile (overall 1 NM = 1800m).