Turbo Charging Marine Engines Maintenance Turbochargers -surging,

Turbo Charging Marine Engines

(Turbo Charging Marine Engines ) Operation And Maintenance Of Marine Turbochargers

Turbo Charging Marine Engines will be discussed for The Best Principles Of Operation And Maintenance Of Marine Turbochargers, I will discuss the complete details from basics to advance level knowledge of Turbo Charging Marine Engines. I have worked on many makes of Turbocharger in my last 43 years as a Marine Engineer and Power plant Engineer. This post (Operation And Maintenance Of Marine Turbochargers)will be the best guide for all marine Engineers and students.

The Swish Engineer Alfred Buchi invented the Turbocharger

The Turbocharger of Marine Diesel Engine is an Integral Part of a ship Engine. It is a waste energy recovery system that uses the engine exhaust to rotate the turbine and supplies fresh air to the combustion chamber through a compressor fitted on the same shaft. With the use of a supercharger.

Working Principle

Turbocharger description

Image credit- ABB Turbo Systems Ltd

A Turbocharger is a machine that consists of the following main components.

Both Turbine and Compressor are mounted on a common shaft

Description of Turbocharging Principles

The Exhaust gases from Diesel Engine enter the Turbocharger through gas inlet casing and nozzle ring to the turbine wheel.
The turbine wheel uses the exhaust gas energy to rotate the compressor wheel. The compressor sucks the fresh air and sends the air to cylinders after compressing.
Exhaust gases pass out to the atmosphere through the exhaust manifold connected to the gas outlet casing.
The necessary air required for the operation of the engine is compressed in the Turbocharger. This air is drawn through the suction filters silencers and sends to the compressor wheel. Compressed air is passed through the diffuser and leaves the Turbocharger through the compressor casing.
We will explain the detail of all the components in the further discussion of the design and construction of components.
Rotor runs in two radial plain bearings/Ball bearings depending upon the design of the Turbocharger. Bearings are lubricated either with the engine lubricating system or with its pump as per the design and type of Turbocharger. We will explain the bearing Lubrication system and the type of bearings used further in a detailed description.

1) Turbocharging will increase the power for an Engine of the same size, or in other words, it would reduce the size of an engine with the same power output.

2) It will reduce SFOC ( Specific Fuel Consumption).

3) Thermal loading of the engine will get reduced by the shorter burning period of fuel.

There are the following three methods of Turbo Charging.

2. Pulse Turbo Charging

3. Pulse Converter

Advantages and disadvantages of the methods of Turbocharging

This system is used in main Engine Turbochargers. In a Turbocharger, if we supply the gas at constant pressure. There is an arrangement for taking the exhaust gas at constant pressure from each cylinder. The Exhaust gas from cylinders is discharged into a standard manifold at a pressure higher than the atmosphere. The exhaust gases from cylinders expand in the exhaust valve of an engine to constant pressure in the exhaust manifold and then deliver to Turbine. In the Turbine, exhaust gases expand, and the mechanical work is done. In the Turbine, blown down energy by exhaust in Thermal Energy gets converted into valuable work.

In this type of Turbocharging method, the exhaust gases are maintained at constant pressure.

1.The design of the exhaust pipe is simple.

2. Efficient Turbine can be used.

3. The pressure ratio is higher in compressor and Turbine, making it more efficient in recovery of exhaust energy.

4. This type of arrangement lowers the specific fuel consumption compared to other turbocharging methods (Pulse-type).

5. This system makes the Turbine run at higher efficiency by supplying the exhaust gases at constant pressure and temperature.

6. There is no limitation on Engine speed by the pressure wave in the exhaust pipes.

1.Exhaust pipe size is significant to maintain the constant pressure.

2. Inefficient scavenging

3. At part load, turbine efficiency reduces due to the partial entry of exhaust gases.

4. Losses latent in mixing this high-velocity gas with a large volume of low velocity can’t be recovered.

5. Due to sluggish acceleration against the increased load, the system’s response is considerably poor and is unsuitable for two-stroke engines.

This system is used in generators. In this turbocharging short and small exhaust pipe connects each cylinder port to the Turbine. The kinetic energy associated with the blowdown exhaust gases is utilized. Exhaust pipes are so grouped in a manner that the overlap of exhaust gases doesn’t takes place. There is no instability of the gases entering the turbocharger.

Immediately upon the exhaust valve opening, the top part of the blown-down exhaust energy is converted into pulses. These pulses are supplied to the Turbine through narrow passages exhaust pipes converting the thermal energy into work.

The amount of exhaust gas at the different inlets of the Turbine is diverse and variable in time.

Rapid action is desired due to the use of this system in low-pressure turbines. This system is more suitable for a multi-cylinder engine. Pulse turbocharging is mainly used in large diesel engines

2. Better scavenging is achieved at low loads due to the reduced pressure below the scavenging pressure.

3. Efficient recovery of blown-down energy as compared to constant pressure system.

4. Exhaust process of cylinders doesn’t interface with each other due to separate exhaust pipes.

2. In Multi-cylinder Engines, complicated Inlet and exhaust pipe arrangements are desired.

3. Limitation in Engine speed.

4. Disturbed scavenging process in case the distance traveled by waves is long to reach the Turbine.

5. Less turbine efficiency in case of the single or two-cylinder engine.

In the Pulse Converter Turbocharging system, various exhaust manifolds are connected in a specially designed venturi junction. In the nozzle section of the century pressure, a pulse is converted to kinetic energy. Its design of century as an ejector creates a suction effect in the exhaust lines and helps in the engine’s scanning process. The diffuser section of the century pressure gradually increases, supplying the high-pressure exhaust to the Turbine.

Due to the engine’s quick response, this system is suitable and efficient even at part load conditions for low-pressure turbines.

Construction

Marine Engine Turbocharger consists of mainly two parts the blower side and the turbine side. The turbocharger consists of a single-stage impulse turbine connected to a centrifugal impeller on the other side through a shaft. Both the side is provided with casing which carries Turbine and Blower. The blower side casing consists of a filter to sub clean air without dust and particles, damaging the compressor blower blades. A diffuser is provided in the blower side for increasing the pressure of sucked Air,

On the Turbine side, an inlet casing is provided, which gathers the exhaust gases to the turbine blade. It also has a nozzle ring to convert the pressure into kinetic energy before hitting the turbine blade. The shaft is carried on Bearings, which helps the turbocharger rotate at an extremely high speed of about 5000 to 10000 RMP, depending upon its size. Bearings are Bush or Ball and roller type.

Marine Turbocharger Parts And function

The compressor Impeller

Compressor Impeller is a radial centrifugal type component. Air is drawn through the filter to the Impeller’s eye. The rotating compressor creates a low-pressure area, accelerated to the periphery of the Impeller, and leaves with high velocity.

The material of the Impeller is either titanium or aluminum alloy. The aluminum impeller has short life due to the creep.

The final Air temperature decides the creep.

Turbine

The turbine rotates the compressor impeller using exhaust gas.

· Material of Turbine blades is Nickel chrome alloy or nimonic material with excellent resistance to creep, fatigue, and corrosion.

· Blade roots are of fir tree shape, which assures positive fixing

· The root is usually slack fit to allow for differential expansion of the rotor.

· Lacing wire is used to dampen vibration.

Diffuser

Once the air leaves the compressor it passes through the diffuser. The diffuser consists of vanes as shown. Due to the configuration air slows down when it leaves the diffuser that is there is a conversion from kinetic energy to pressure energy.

Nozzle ring

The nozzle ring has to be resistant to high temperatures and corrosion. It is made from a chromium-nickel alloy to resist creep. Heat-resisting molly grown nickel steel or Nemonic alloy. The cross-sectional area of each nozzle decreases as the exhaust gas passes through that. Because of this gas is forced to speed up kinetic energy will increase through this and pressure and heat energy will decrease.

Labyrinth seal

labyrinth seals are fitted to the shaft and casing to prevent leakage of exhaust gas into the turbine and bearing or to prevent oil from being drawn into the compressor. On the other side of the compressor, the impeller is also provided with a labyrinth. It restricts the leakage of air to the gas side to assist sealing affect air from the compressor volute casing is supplied.

Types of Turbocharger On Ship

Axial flow type (TCA Type)

2) Radial flow type. ( TCR Type)

The turbine design decides the above type of turbochargers

Axial flow type ( TCA Type Turbocharger) Marine

Axial flow turbine after the nozzle ring gas moving with high velocity is directed to the turbine blades as the gas changes the direction due to the blade profile. a force is imparted onto the blade causing it to turn the turbine wheel.

Radial flow type (TCR Type Turbocharger)

Radial flow turbine nozzles work in a similar way as in the axial flow type. that is pressure energy is converted into kinetic energy and the gas is directed onto the turbine wheel is the gas passes through the turbine wheel it changes direction and this change of direction produces an impulsive force that turns the wheel.

Turbocharger Function

Turbocharger operation is the important discussion of Turbocharging Diesel Engines

When the engine is started, it compresses and burns the fuel. Some of the energy is wasted and produces exhaust gas which needs to be drawn out of the cylinder using an exhaust valve. These exhaust gases from each cylinder move to an exhaust box. The turbine is driven by engine exhaust gas. Exhaust gas from the compartment enters via gas inlet casing of turbocharger. The gas expands through a nozzle ring, where the pressure energy is converted into kinetic energy. This high-velocity is directed onto the turbine blades, where it drives the turbine wheel and the compressor connected to the same shaft. IT also rotates the blower at high speed.

Exhaust gas gets converted into kinetic energy by Nozzle Ring. It is fabricated from heat-resisting Molychrome nickel steel or a Nimonic Alloy which can withstand the high temperature and corrosion resistance. The turbine side outlet is connected to the exhaust uptake pipe, which leads the exhaust gases to the ship’s funnel.

On the airside, Air is drawn into the filter. Air enters the compressor wheel axially, where it achieves high velocity. Air goes out and passes through a diffuser where some of the kinetic energy is converted into pressure energy by exiting the impeller. In the end, the Air is then passed into a volute casing where further energy conversion takes place. The outlet air is supplied through the Air cooler arrangement on the ship’s engine. The structure is a shell and tube type cooler where seawater passes through the cooler to reduce the air temperature. This cool AirAir is supplied as fresh AirAir in the scavenging air trunk from where it takes the supply of combustion air through the liner’s scavenges port.

During the engine’s start, the turbocharger is also at a standstill; hence no fresh is supplied to the scavenge port. Fresh Air is essential to start the combustion. Therefore additional blowers are installed, which are switched on during the start of the engine. When the RPM of the motor reaches and the turbocharger supplies, the scavenge Air and the blower are cut off.

Turbocharger cooling arrangements

Gas Engine Turbochargers are water-cooled Due to the high exhaust gas temperature as compared to Diesel Engines. In Gas Engines Turbine Housing of the Turbocharger is water-cooled. Modern synthetic oil is also used to cool the Turbochargers.

How is a turbo lubricated?

Turbocharger Bearing Lubrication

Image credit-dieImage credit-dieselship.comselship.com

The Turbocharger is fitted with the following two types of Bearings.

1. Ball/ Roller type

2. Bush/Journal white metal bearings.

Ball/ Roller type Bearing

Resilient mounting and spring damping prevents bearing damage. In these types of bearings, the rotor shaft is supported at the ends.

Blower side bearing is with double-row ball bearing. This Bearing takes the axial load of the shaft and is provided thrust packings on both sides of the Bearing in the housing.

Leaf springs prevent the vibration and balls blabbing moments. The Bearing is fully packed in the casing. The bottom part of the casing is used as a sump for bearing Lube oil.

Lubrication of this type of Bearing is through a gear pump. This gear pump gets the Turbine shaft drive and supplies the oil to the jet’s Bearing. The oil level is checked through a sight glass provided on the casing. One oil filling plug and drain pugs are supplied in the case.

The Bearing is with a single row on the turbine side and provides the space for the moving parts’ linear expansions. The lubrication arrangement is similar to the compressor side bearing Lubrication.

Advantages

• Easy access for the inspection of the pump.
• No additional fittings are required since there is an independent sump.
• The choice of oil availability is easier.
• Direct cost is low.
• Lubrication improves at a higher speed.
• Friction losses are low at high speed.

Disadvantages

• Inadequate Lubrication at starting and stopping/ lower speed.
• Hard brinelling marks can take place on the balls if there is a lack of oil supply.
• There could be significant damage to the Turbocharger in the event of bearing failure.
• The additional cost of lube oil due to different grades of oil

Journal sleeve/Bush type bearing

his bearing arrangement has been shown in the following diagram. The sketch shows radial flow type Turbo arrangement. In this type of arrangement, Lubrication is a forced lubrication type. Oil is supplied either by a gear-driven pump or pressure lubrication by the engine lube oil system itself. This arrangement is employed in radial-type turbochargers.

Bering support is inboard. The turbine and compressor wheel are fitted outboard on both ends of the shaft.

Due to the high speed, a sleeve type of Bearing is used for this type of Turbocharger. Bearing Lubrication is through the engine oil system.

Lubricating oil is available all the time at Turbocharger. In the event of starting and stopping, the Bearing is lubricated by an engine lube oil priming pump.

Advantage

.Continuous availability of lubricating oil.

· No additional cost of Lubricating oil since the engine oil is used for the Turbocharger.

· No chances of bearing failure since hydrodynamic Lubrication persists due to force Lubrication.

· No frequent change of oil since the oil change is with the engine oil change.

· Lubrication is suitable at all speeds.

Disadvantages

. The primary cost is high due to the additional requirements of pumps, tanks, piping, etc.

· There are always chances of any foreign material traveling inside the lubricating system and might cause damage to the bearings and other crucial parts.

· Delay and Deterioration of engine lubricating oil might damage the Bearing.

Variable Geometry Turbochargers

Variable Geometry Turbochargers are Turbochargers where movable nozzle rings vanes are replaced for conventional fixed blades. This nozzle ring can change the angle to control the exhaust flow on the turbine blades. These blades have the engine to control the volume of AirAir with the fuel along with the entire engine load range. VGT or VTA consists of nozzle rings that are equipped with angle-changing content. Each

vane is connected to the ring using the lever, which reduces the thermal Hysteresis and increases the positional accuracy.

Advantages of VTA

Works on the entire range of the Engine

2. No need for the Auxiliary Blower

3. Reduces fuel consumption

4. Reduces exhaust stroke emissions and reduces air pollution

5. Lowers CO2, SOX, NOx Emissions

6. Reduces Soot and carbon deposits on combustion and exhaust space.

7. Reduces fouling of Parts

8. Improved Overall efficiency of Engine

K Value in Turbochargers

K value in a Turbocharger is a distance between the rotor shaft end and the flange of bearing cover measured by the blower side.

Purpose of K value in turbochargers

K value ensures the rotating impeller does not touch the stationary blower casing cover in case of thrust bearing has been worn out.

Most Experienced Problem In Turbochargers

Surging (Maintenance Marine Diesel Turbocharger)

For understanding the phenomenon of surging in Turbocharging Diesel Engines, let us consider the following conditions.

P1 (Pressure 1) Pressure from the outlet of the compressor

P2 (Pressure 2) Pressure from Charge Air Cooler

M (mass Flow)

Case A: — P2/P1=1, and M is on the Higher side. In this case, it indicates no restriction to the flow of mass since boot the pressures are equal, and mass flow of air is also on the higher side.

Case B:- P2/P1 ≥1 and mass flow M offer is a little less

Case C:-P2/P1 ˂ one and Mass flow is wholly decreased.

Case C is when the Pressure ratio of P2 /P1 is less than one and mass flow is Negligible, and in this condition, surging occurs.

Leading Causes for the Turbocharger Surging

1. Excessive exhaust backpressure
2. Chocked scavenged ports
3. Excessive turbo outlet restriction
4. Fouled Nozzle ring blades
5. Leaky Exhaust valves
6. Misfiring in one or more cylinders
7. Fouled Compressor wheel Blades
8. Chocked Charge Air Cooler
9. Turbo outlet pressure leak
10. Erratic engine or engine control operation
11. A muffler with a large amount of water in it.
12. Sudden Load Change
13. Fire in Scavenge space or Exhaust Trucking
14. A collapsed air cleaner filter element.
15. Several cylinders were misfiring.
16. A badly worn fuel control linkage.
17. An improperly adjusted governor.
18. A worn governor actuator.
19. A voltage regulator with an intermittent output fault.
20. Damaged turbine and compressor blades on the turbo.

We have also (rarely) seen problems with turbo’s returned from overhaul with updated or incorrect parts that caused the issue after overhaul.

I have observed the main reason for surging in exhaust turbines is a fault in the exhaust valves, either timing or leaking by. One other long shot to check is there a restriction in the exhaust trunking or stack. Is the exhaust stack diameter correctly sized, without restrictive bends, or an exhaust boiler or silencer choked?

How to check the efficiency of Turbocharger in running condition

Turbine Efficiency= Turbine Efficiency (Drop-in Turbine side) + Blower Efficiency (Filter chocked) + Mechanical Efficiency

1. If the temperature difference is more than, it indicates that the Turbocharger is running efficiently. If the difference in temperature is more than it suggests, the fouling of internal Turbocharger moving parts

2) The readings of Manometer at compressor side. There is an absolute pressure gauge before the filter, and after the filter, a manometer is installed. The reading at Manometer will indicate the choking of the filter. If the filter is choked, then the air-induced mass flow will be less, and combustion will be poor.

3) If the charge air cooler is choked, then the air-induced density will be less and will result in poor combustion. The difference in water temperature between inlet and Outlet of charge air cooler should not be ˂ 50C

4) The temperature difference of air across the charge air cooler should be between 350C to 400C.

Special Instructions for Blocked Turbocharger ( TC Breakdown)

No action is to be taken for the 4-stroke engine with one turbocharge and separate air receiver. The engine can be operated as a naturally aspirated engine according to the instructions of the manufacturer

Common air receiver

Suppose the engine is equipped with a common air receiver and separate exhaust gas receivers. In that case, the compensator at the compressor outlet of the damaged turbocharger must be dismantled, and the air duct on the engine side must be isolated. Otherwise, the undamaged turbocharger can spin “unloaded” and run at Overspeed.

Power pulses will apply on the locked rotor for the pulse-type turbocharger. Therefore, the following operating limits should not be exceeded: ƒ In systems similar to those with constant pressure (1 gas inlet), the engine can be operated up to a maximum of 25% engine load. The pres[1]sure in the charge-air receiver must not exceed 0.9 bar overpressure. With pulse supercharging (2…4 gas inlets), the engine can be operated up to a maximum of 20% engine load. The pressure in the charge-air receiver must be less than 0.5 bar.

Two-Stage Turbocharging

Two stages Turbocharger improves the efficiency of four-stroke diesel engines by lowering the specific fuel consumption. The basic principle is simple: with standard single-stage turbocharging, the exhaust gases from the cylinders are fed through a central exhaust gas pipe and into a high-pressure turbocharger. Here, the exhaust gas is powered by an axial turbine connected over a shaft that drives a compressor wheel that delivers charge air to the cylinders under high pressure. The remaining energy of the exhaust gases is used to drive a second low-pressure turbocharger.
The compressor wheel of this turbocharger draws in charge air from its surrounding area. Compresses it the first time and delivers it to the high-pressure turbocharger, which compresses it again to increase air density and turbocharger efficiency. The charge air is cooled down after each compression process, unlike conventional turbocharging, which only permits around three bars’ charge pressures. The charge air of the Engine is delivered to the cylinders with almost six bars.
The benefits of the two-stage turbocharged Engine speak for themselves. Depending on the operation mode, it can increase the Engine’s continuous power output from 1050 to1200 kilowatts per cylinder.
Can reduce the nitrogen oxide emissions from the level of 1850 milligrams per standard cubic meter stipulated by the practical World Bank guideline down to one thousand four hundred and eighty milligrams per average cubic meter. In typical operation with a power output of 1050 kilowatts per cylinder, the engine can operate with a fuel consumption of only 173 grams per kilowatt-hour. The two-stage turbocharged engine Engine offers high operation flexibility at low emission levels and unparalleled fuel consumption

Maintenance of Turbocharger

Turbine Side water washing

Procedure-Marine Engine Turbocharger Maintenance

1. Bring down the RPM of the engine so that the Exhaust Temperature at Turbocharger Inlet is 2000C and RPM is 2000.
2. Wait for 10 minutes after the load reduction.
3. Connect the hose
4. Open the water washing Cock
5. Open the drain cock
6. Carry out the water washing for at least 20 to25 minutes. During this process, some water will be coming out and some will get evaporated.
7. Stop the water washing once the clean water from the drain is observed.
8. Increase the RPM slowly.

Disadvantages of Water washing

1. Thermal Stresses
2. Corrosion.

Procedure for Dry Cleaning (Granules/Girt washing)

1. Cleaning is carried out during High Engine Load. ( Minimum 75%)
2. Increase the RPM of the Engine.
3. Before opening the blowgun open the closing valve 1 and check for free passage.
4. Fill the granules in the Gun
5. Connect to the working air system ( 5 to 7 bar)
6. Open the valve slowly until a whistling sound indicates the blowing in of granulates has taken place.
7. Injection time is approximately 2 min.

In this method, there will be no problem with Corrosion and thermal stresses.

Water Washing of Turbine Side

Cleaning Procedure

1. Run the Engine at 20 % load and let the engine stabilized at this load
2. Open the drain cock at the Turbocharger outlet and check for free passage.
3. Turn the Three-way cock to position2 “open” and check for free passage. If found OK then turn to water was position 3 Wash
4. Connect the water supply to the water wash system
5. Activate the maneuvering valve
6. Open the regulating valve and adjust the water flow until the drain flow is approximately 02.5 l/min.
7. Continue the water washing for 5–10 minutes or until the drain water is free of particles.
8. Release the maneuvering valve and disconnect the water supply.
9. Turn the 3-way cock to position-1,” closed” and check that the water drain has stopped.
10. Continue at this load for at least 5 min. before increasing the load to the normal condition.
11. After the water washing, the engine should run for at least 1 hour before stopping.

Note: The regulating valve has to be opened slowly.

The maneuvering valve must not be locked in the open position.

The water injection time mentioned in item 6 must be not exceeded.

Procedure for Turbocharger Overhaul

Overhauling is carried out as per the maintenance of turbochargers. The procedure for overhauling diesel engine turbocharger is explained below

1.Lock the Engine starting Mechanism.

2. Dismantle the Turbocharger air inlet filters.

3. Drain the lube oil from both ends.

4. Open and remove the bearing covers from both ends.

5. Remove the locking devices.

6. Remove oil suction pipes.

7. Tighten again the hexagon screws of these bearing housings.

8. Always check the deflection associated with the deviating t nozzle by making use of a pick tester and magnetic stand.

9. Take out the deviating nozzle with a screwdriver.

10. Take the measurement of the K value at the blower side by making use of a level micrometer or caliper and with the right angle.

11. Lock the rotor with a special device.

12. Remove out the lubricating disk.

13. Remove out both the bearings with bearing extraction.

14. Preserve the removed parts to guard them against any dirt and moisture by wrapping them with oily paper.

Turbocharger overhauling Checks

Check the deflection of deviating nozzle ring.

2. Measure the K value on the blower side.

3. Change the bearing on both ends with the brand new one (because bearing service life is as per the turbocharger overhauling schedule).

4. Inspect the turbine and blower side after cleaning with chemicals.

5. Assess the condition of the labyrinth seal ring.

6. Clear the seal air range that is a labyrinth

7. Check the casing for break & wear

8. Condition of Blade

9. Check the static balancing after the re-assembly.

10. Always check Impeller and clearance that is casing.

Bearing Change Schedule

.Depending on Running Hour

2. As per the results of measured clearances.

3. If found in damaged condition.

4. Any heavy vibrations

How exactly to check the deflection of the deviating nozzle?

1. Simply by using Pick tester &

2. Magnet stand

What measurements tend to be taken during auxiliary motor turbocharger renovation?

1. K value, it is a length amongst the rotor shaft end while the flange of bearing cover measure at blower part (axial clearance).
2. Check approval this is certainly radial at plane bearing), by placing clock gauge regarding the shaft from the top and clamp by screwdriver from the base, record the clearance.
3. Clearance between Rotor and casing for new casing or brand new rotor) (L & M values)

Procedure to measure turbocharger axial and radial clearances (Turbo Charging Marine Engines)

Clearance in the axial direction

Push the shaft by screw jack and measure by Depth Gauge (0.2–0.3 mm)

Radial Clearance

Lift the shaft radially and measure by Dial Gauge (0.15 — .02 mm)

Why turbocharger exhaust temperature lower than inlet temperature?

Due to the drop in scavenge temperature and high exhaust temperature increases.

Exactly what will occur is an oil leak in the turbocharger system?

1. Due to the oil leak in the air system, cooling surfaces are covered thereby reducing the cooling efficiency. This will drop the scavenge temperature and exhaust temperature will rise high.
2. If oil leaked into the exhaust side, Carbon deposits from the nozzle & turbine knife. It causes surging, decreases blower efficiency, and fire into the fatigue piping fire that is(uptake

Turbocharger over Run

Causes

1. Happens in constant pressure turbo recharger type Engines
2. triggered due to fire and or detonation of scavenging system
3. Leaked or excess lubricating oil causes the exhaust trunk fire.

Effects

1. Damage of TC bearing casing.
2. Fire in Engine space

Prevention

1. Regular cleaning of scavenging area.
2. Regular cleaning of the exhaust pipe.
3. Maintaining the proper fuel combustion.
4. Good maintenance and upkeep of Liners, Pistons, Piston Rings, Injectors, and cylinder lubrication.
5. Avoid low load operation.

Factors behind Turbocharger Vibration

1. Unbalancing
2. bearing flaws
3. Deposits in the nozzle ring
4. Impingement
5. Surging, Scavenge Fire, Overloading

The Lambda Controller

The Lambda Controller is used to prevent excess fuel injection in the combustion chamber of a Diesel Engine that can be burned during a momentary load increase. This process is carried out in relationship with the fuel index and the scavenge air pressure. Lamda controller is used as a stop cylinder also.

Benefits of Lambda Controller

1. Reduces the visible smoke during the sudden transitory load increase.
2. Improves the load capability
3. Reduces fouling the exhaust gas pathways.
4. Limits the fuel index during the starting of the engine.

Originally published at https://www.marinediesel.co.in on April 4, 2021.