Open type indicator diagram for four stroke engine

5.3. How you can calculate the Maximum combustion pressure, Compression pressure and Mean indicated pressure from indicator diagram?

– Maximum combustion pressure (bar);

– Compression pressure (bar);

– Mean indicated pressure (bar);

Where: P_MAX (mm) – Maximum combustion pressure from indicator diagram;

P_COM (mm) – Compression pressure from indicator diagram;

m_S (mm/bar) – Spring factor;

A_IND (mm2) – Indicator diagram area;

L_IND (mm) – Indicator diagram length.

5.4. How you can calculate the engine Indicated power and Effective power (output)?

– Engine Indicated power (IKW);

– Engine Effective power (EKW);

Where: – Cylinder constant (–);

P_ME = P_MI – P_MEC – Mean Effective pressure (bar);

P_MEC (bar) – Mechanical loss pressure (≈ 1 bar for two stroke B& W engines);

n (rpm) – Engine speed;

i (–) – Engine cylinder numbers;

D (mtr) – Cylinder diameter;

S (mtr) – Engine piston stroke;

m (–) – Stroke factor.

5.5. What kind of power for the diesel engines do you know? I know the engine Effective power, Indicated power, Mechanical Loss power; the generator Active power, Reactive power and Full power.

5.6. How you can determine the engine Effective power (output) by indirect way?

5.6.1. By hourly fuel oil consumption:

N_EFF = f (G_DO) – from Shop trial test results model diagrams (EKW);

Where: – Corrected to shop trial test results hourly DO consumption (kg / hr);

G_FO (kg / hr) – hourly HFO consumption from engine performance data;

L_CV^FO (kcal / kg) – HFO Lower Calorific value from engine performance data;

L_CV^DO (kcal / kg) – DO Lower Calorific value from Shop trial test results.

5.6.2. By multiply of Fuel pump index FPI (fuel rack position FRP) on Engine speed:

N_EFF = f (FPI_DO · n) – from Shop trial test results model diagrams (EKW);

Where: – Corrected to shop trial test results Fuel pump index with DO (mm);

FPI_FO (mm) – Fuel pump index from engine performance data;

L_CV^FO (kcal / kg) – HFO Lower Calorific value from engine performance data;

L_CV^DO (kcal / kg) – DO Lower Calorific value from Shop trial test results.

5.6.3. By Turbocharger – TC speed:

N_EFF = f (N_TC^DO) – from Shop trial test results model diagrams (EKW);

Where: – Corrected to shop trial test results TC speed (rpm);

N_TC^FO (rpm) – TC speed from engine performance data;

T_INL^FO (^OC) – TC air filter inlet temperature from engine performance data;

T_INL^DO (^OC) – TC air filter inlet temperature from Shop trial test results;

5.6.4. By Scavenging Air pressure:

N_EFF = f (P_SC^DO) – from Shop trial test results model diagrams (EKW);

Where: P_SC^DO = f (P_SC^FO; T_INL^FO; T_INL^DO; P_ATM; T_CW^FO; T_CW^DO – Corrected to shop trial test results scavenging air pressure (bar);

P_SC^FO (bar) – Scavenging air pressure from engine performance data;

T_INL^FO (^OC) – TC air filter inlet temperature from engine performance data;

T_INL^DO (^OC) – TC air filter inlet temperature from Shop trial test results;

T_CW^FO (^OC) – TC air cooler cooling water inlet temperature from engine performance data;

T_CW^DO (^OC) – TC air cooler cooling water inlet temperature from Shop trial test results;

P_ATM (bar) – Barometric pressure from engine performance data.

5.7. Can you comment the procedure for Main Engine preparation for starting up? Main Engine preparation procedure for starting up to be done with the steps as follows:

- to check that the Main Engine Fuel oil system, Lubricating oil system, Sea water cooling system and Fresh water cooling system in operation;

- to open the cylinders indicator cocks;

- to engage the Main Engine turning gear;

- to turn the engine by turning gear and pre–lubricate the cylinders liners by manual pumping the Cylinder oil lubricators for the period of 10¸ 15 minutes;

- to disengage the Main Engine turning gear;

- to open the Main Engine Main Starting valve and Control air valve;

- to aknowledge the Main Engine alarms and make shore that all alarms gone;

- to blow through the Main Engine by starting air via engine control lever from Engine Control Room;

- to close the cylinders indicator cocks;

- to trial start the Main Engine by starting air via engine control lever from Engine Control Room;

- to change over the Main Engine control from Engine Control Room to the Bridge.

5.8. Which engine faults are effected to the combustion process do you know? Faults in the cylinders tightness, fuel injection equipment and turbocharger system.

5.8.1. Cylinders tightness faults as follows:

- Piston rings are worn out (compression pressure – maximum combustion pressure are decreased, exhaust gas temperature is increased);

- Cylinder liner is worn out (compression pressure – maximum combustion pressure are decreased, exhaust gas temperature is increased);

- Exhaust valve is leaking or burnt out (compression pressure – maximum combustion pressure are decreased, exhaust gas temperature is increased);

- Piston crown is worn out (compression pressure – maximum combustion pressure are decreased, exhaust gas temperature is increased);

- Combustion chamber volume is too high (compression pressure – maximum combustion pressure are decreased, exhaust gas temperature is increased);

- Combustion chamber volume is too low (compression pressure – maximum combustion pressure are increased, exhaust gas temperature is decreased).

5.8.2. Fuel injection equipment faults as follows:

- FO supply (booster) pump is worn out (mean indicated pressure – mean effective pressure – indicated power – effective power are decreased, fuel pump index is increased);

- FO filter is dirty or clogged (mean indicated pressure – mean effective pressure – indicated power – effective power are decreased, fuel pump index is increased);

- Fuel injection timing is too high (maximum combustion pressure is increased, exhaust gas temperature is decreased);

- Fuel injection timing is too low (maximum combustion pressure is decreased, exhaust gas temperature is increased);

- Fuel injection pump is leaking (plunger or suction / delivery valve are leaking) (mean indicated pressure – mean effective pressure – indicated power – effective power – exhaust gas temperature are decreased, fuel pump index is increased);

- Fuel injection pump barrel / plunger is sticking (cylinder is cut–off);

- Fuel injection valve deposit or sticking (cylinder is cut–off);

- Fuel injection valve is leaking (maximum combustion pressure is decreased, exhaust gas temperature is increased);

- Fuel injection valve opening pressure is too high (maximum combustion pressure is decreased, exhaust gas temperature is increased);

- Fuel injection valve opening pressure is too low (maximum combustion pressure is increased, exhaust gas temperature is decreased).

5.8.3. Turbocharger system faults as follows:

- Air inlet filter is dirty (scavenging air pressure – compression pressure – maximum combustion pressure are decreased, exhaust gas temperature is increased);

- Compressor diffuser is dirty (scavenging air pressure – compression pressure – maximum combustion pressure are decreased, exhaust gas temperature is increased);

- Compressor wheel is dirty (scavenging air pressure – compression pressure – maximum combustion pressure are decreased, exhaust gas temperature is increased);

- Compressor air inlet casing is dirty (scavenging air pressure – compression pressure – maximum combustion pressure are decreased, exhaust gas temperature is increased);

- Scavenging air cooler air side is dirty (scavenging air pressure – compression pressure – maximum combustion pressure are decreased, exhaust gas temperature is increased);

- Scavenging air ports are dirty (compression pressure – maximum combustion pressure are decreased, scavenging air pressure – exhaust gas temperature are increased);

- Exhaust gas protection grid is dirty (scavenging air pressure – compression pressure – maximum combustion pressure are decreased, exhaust gas temperature is increased);

- Turbine nozzle ring is dirty (scavenging air pressure – compression pressure – maximum combustion pressure are decreased, exhaust gas temperature is increased);

- Turbine gas inlet casing is dirty (scavenging air pressure – compression pressure – maximum combustion pressure are decreased, exhaust gas temperature is increased);

- Turbine wheel is dirty (scavenging air pressure – compression pressure – maximum combustion pressure are decreased, exhaust gas temperature is increased);

- Turbine gas outlet casing is dirty (scavenging air pressure – compression pressure – maximum combustion pressure are decreased, exhaust gas temperature is increased);

- Exhaust gas boiler gas side is dirty (scavenging air pressure – compression pressure – maximum combustion pressure are decreased, exhaust gas temperature is increased).

5.9. What type of Fuel Injection pumps do you know? Fuel injection pump with adjustment by the end of injection, fuel injection pump with adjustment by began of injection, fuel injection pump with combined adjustment and fuel injection pump with adjustment by the end of injection with VIT–system (Variable Injection Timing system):