7 семестр (Бормотов А) / 1man_bw_l23_30_chn_23_30_instruktsiya_po_ekspluatatsii_1 / MAN-BW L23-30 H Vol-1 (Instruction)+

L23/30H

08028-0D/H5250/94.08.12

Description

The built-on fresh water pumps in the high and low temperature circuits are of the centrifugal type. They are mounted in the front end box and are driven through the gearing.

General

The pump bearings are lubricated automatically with oil from the lubricating oil system of the engine.

If the pump leaks and the shaft sealing rings are worn, it is recommended to replace the shaft seal, see Working card 516-02.00.

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Note: Running trouble with the pump, apart from mechanical faults, is most often due to leaks in the suction line. It is therefore essential that all packings and gaskets are in order and that they are renewed when necessary. Even a tiny hole in the suction line will reduce the pump capacity.

Trouble Shooting

It is necessary to replace damaged plates or gaskets.

First examine the external conditions around the plate heat exchanger in order to localize the cause of the damage. Do this very carefully.

General

Fatiguefracturewillnormallynecessitatereplacement of all plates and gaskets as there may be a risk of fatigue fracture in all the material.

In case of corrosion, all plates must be examined carefully!

Concerning the work to be carried out see Working card 515-06.00.

General

Non-Visible Leakage

08028-0D/H5250/94.08.12

08028-0D/H5250/94.08.12

Requirement

This document is valid for the following engine types: L16/24, L21/31, L23/30H, L27/38, L28/32H, V28/ 32H, V28/32S and L32/40.

Heavy Duty lubricating oil (HD-Lube oil) has to be used coresponding to at least type CF after API service system (http://api-ep.api.org/filelibrary/ ACF1E1.pdf). Further the oil should be rust and oxidation inhibited.

Viscosity

Marine

Engine SAE class L23/30H, L+V28/32H

30* 105 mm2/sec at 40° C

L16/24, L21/31, L27/38, L32/40

40 145 mm2/sec at 40° C

Stationary

L16/24, L21/31, L27/38, L23/30H,

L+V28/32H, V28/32S

40145 mm2/sec at 40° C

*At cooling water temperatures above 32° C SAE 40 oil can be used. In this case, please contact MAN B&W, Holeby.

Guiding Values for TBN

When selecting lubricating oil, attention must be paid to the fuel oil sulphur content.

Marine GenSet engines are normally running at low load compared to propulsion engines, therefore the absolute fuel consumption is lower and consequently the lube oil is exposed to a smaller amount of sulphur. Therefore the TBN-value (Total Base Number) of the lube oil has to be lower to neutralise the sulphur from the fuel.

The consumption of lube oil has influence on recommended initial TBN value. When the lube oil consumption is high, low TBN values is recommended, and opposite. How to evaluate the lube oil consumption, please see section B 12 15 0 "Specific Lubricating Oil Consumption".

General

Based on typical load profile for marine GenSet (5060% of rated power) and for stationary GenSet (50100% of rated power)

For all engines except L32/40

For engines L32/40

For low loaded marine GenSet engines are recommended the lowest TBN values and for high loaded stationary engines are recommended the highest TBN values. If load profile is different, this should be taken in consideration. However, the operation results are the criteria that prove which TBN is the most economical one for efficient engine operation.

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General

During operation of trunk engines the lubricating oil will be contaminated slowly by small particles originating from the combustion.

The burning of heavy fuels will normally increase this contamination due to the increased content of carbon residues and other impurities.

Contamination of lubricating oil with water, fresh or salt, can also take place.

A certain amount of contaminants can be kept suspended in the lubricating oil without affecting the lubricating properties.

But the condition of the lubricating oil should be kept under observation by analyzing oil samples. See also 504.04 "Criteria for Cleaning/Exchange of Lubricating Oil".

The engine bearings are protected by the full-flow lubricating oil filter built onto the engine, the filter cartridges having a fineness of 15 micron and the safety filter a fineness of 60 micron.

The condition of the lubricating oil can be maintained/reestablished by exchanging the oil at fixed intervals or based on analysis results.

Operation on Marine Diesel Oil (MDO)

The built-on full-flow dept filter cleans the oil thoroughly. For operation on MDO we recommend to install a built-on centrifugal by-pass filter too.

Operation on Heavy Fuel Oil (HFO)

For engines operating on HFO a lub. oil centrifugal unit is required.

Continuous lub. oil centrifugation plus a built-on fullflow depth filter clean the oil in a sufficient and safe way. Any other filter system is not necessary, but not wasted.

General

A more economical solution is to maintain the condition by continuous treatment. Experience has proved that centrifuging is superior to other methods of cleaning lubricating oils.

The optimum cleaning effect is achieved by keeping the lubricating oil in a state of low viscosity for a long period in the centrifuge bowl.

Low viscosity is obtained by preheating the lubricating oil to a temperature of 85°C - 95°C.

Slow passage of the lubricating oil through the centrifugal separator is obtained by using a reduced flow rate and by operating the separator 24 hours a day, stopping only when cleaning of the bowl is necessary.

When treating detergent type lubricating oil, the flow rate is usually recommended to be reduced to 1525% of the rated flow of the separator.

In order to keep the amount of lubricating oil in the engine in good condition, it is necessary to treat 0.3- 0.4 l/kw per hour.

A centrifuge for treating this amount of lubricating oil under the aforementioned derated flow conditions should have a rated capacity of 1.5-2.5 l/kw per hour, but in each case the separator manufacturer's recommendations for capacity and operating instructions should be followed.

For engines with cartridge-type oil filters (depth filters), continuous and efficient purification of the oil in the separator is essential to ensure a long service life for the cartridge filters.

For cleaning of the lubricating oil system after overhauls and inspection of the lubricating oil piping system, see section 515.

Deterioration of Oil

Oil seldom loses its ability to lubricate, i.e. to form a friction-decreasing oil film, but it may become corrosive to the steel journals of the bearings in such a way that the surface of these journals becomes too rough and wipes the bearing surface.

General

In that case not only must the bearings be renewed, but the journals must also be polished. The corrosiveness of the lubricating oil is either due to far advanced oxidation of the oil itself (TAN) or to the presence of inorganic acids (SAN). In both cases the presence of water will multiply the effect, especially an influx of sea water as the chloride ions act as an inorganic acid.

Oxidation of Oils

At normal service temperature the rate of oxidation is insignificant, but the following factors will accelerate the process:

High Temperature

If the coolers are ineffective the temperature level will generally rise.

Ahightemperaturewillalsoariseinelectricalpreheaters if circulation is not continued for 5 minutes after the heating has been stopped, or if the heater is only partly filled with oil.

Catalytic Action

Oxidation of the oil will be accelerated considerably if catalytic particles are present in the oil. Wear particles of copper are especially harmful, but also ferrous particles and rust are active. Furthermore, the lacquer and varnish-like oxidation products of the oil itself have an accelerating effect. Continuous cleaning of the oil is therefore important to keep the sludge content low.

Signs of Deterioration

If circulating oil of inferior quality is used and the oxidative influence becomes grave, prompt action is necessary as the last stages in the deterioration may develop surprisingly quickly, i.e. within one or two weeks. Even if this seldom happens, it is wise to be acquainted with the signs of deterioration.

These may be some or all of the following:

-Sludge precipitation in purifier multiplies.

-Smell of oil becomes acrid or pungent.

-Machined surfaces in crankcase become coffee brown with a thin layer of lacquer.

-Paint in crankcase peels off or blisters.

-Excessive carbon is formed in the piston cooling chamber.

In a grave case of oil deterioration, the system should be cleaned thoroughly and refilled with new oil.

Water Washing

Water washing of HD oils must not be carried out.

Water in the Oil

If the TAN is low, a minor increase in the fresh water content of the oil is not immediately detrimental while the engine is running. Naturally, it should be brought down again as quickly as possible (below 0.2% water content, which is permissible). If the engine is stopped while corrosion conditions are unsatisfactory it should be turned just over 1/2 revolution once every hour (i.e. stop in different positions) while the oil circulation and purifying at a high preheating temperature continue to remove water. Water in the oil may be noted by steam formation on the sight glasses, by appearance, or ascertained by immersing a piece of glass or a soldering iron heated to 200300°C in an oil sample. If there is a hissing sound, water is present. If a large quantity of water has entered the oil system, it may be profitable to suck up sedimented water from the bottom of the tank. Taste the water for salt. If salty, an oil sample should be analysed immediately for chloride ions.

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Replacement of Lubricating Oil

The expected lubricating oil lifetime in operation is difficult to determine. The lubricating oil lifetime is depending on the fuel oil quality, the lubricating oil quality,thelubricatingoilconsumption,thelubricating oil cleaning equipment efficiency and the engine operational conditions.

In order to evaluate the lubricating oil condition a sample should be drawn on regular basis at least once every three month or depending on the latest analysis result. The lubricating oil sample must be drawn before the filter at engine in operation. The sample bottle must be clean and dry, supplied with sufficient indentification and should be closed immediately after filling. The lube oil sample must be examined in an approved laboratory or in the lubricating oil suppliers own laboratory.

A lubricating oil replacement or an extensive lubricating oil cleaning is required when the MAN B&W exchange criteria's have been reached.

Evaluation of the Lubricating Oil Condition

Based on the analysis results, the following guidance are normally sufficient for evaluating the lubricating oil condition.

1.Viscosity

Attention limit: < ±one viscosity grade

Increasing viscosity indicates problems with insolubles,HFOcontamination,watercontamination, oxidation, nitration and low load operation. Decreasing viscosity is generally due to dilution with lighter viscosity oil.

General

2. Flash Point

Normally used to indicate fuel dilution.

3. Water Content

Attention limit: < 0.1

Water can originate from contaminated oil, an engine coolingwaterleakorformedaspartofthecombustion process. If water is detected also Sodium, Glycol or Boron content should be checked in order to confirm engine coolant leaks.

4. Total Base Number (TBN)

The neutralization capacity must secure that the acidic combustion products, mainly sulphur originate from the fuel oil, are neutralized at the lube oil consumption level for the specific engine type. Gradually the TBN will be reduced, but should reach an equilibrium.