Design, operation and maintenance. Engines with electronic control "MAN and Burmeister and Wein - ME marine diesel gas turbine engine

03.09.2019

The nozzle atomizer design of Burmeister and Wein marine diesel engines (Fig. 6.4.5., a) was used with minor changes until a fundamentally new nozzle with a different atomizer was created (Fig. 6.4.5., b).

In the design shown in Fig. 6.4.5., a, the nozzle 10 is pressed into the body 11 (nozzle holder), which is lapped against the lower end of the guide 8 of the needle 7. The upper end of the guide is lapped against the body 1 of the nozzle. With a massive nut 9, the nozzle holder 11, the guide 8 and the lower part of the body 1 are fastened into a single sealed assembly. The pins 5 ensure that the sections of the cooling channels 12 of the fuel line 6 coincide. The nozzle 10 is fixed in the body 11 by a hot fit, which ensures reliable fixation of the nozzle, the holes of which must have a strictly specified direction (the number of nozzles is two or three with the central position of the exhaust valve). Three or four nozzle spray holes have a diameter of 0.95-1.05 mm. To increase the service life of the needle-stop elements, the upper part of the needle 7 is made in the form of a thickened head, and the stop 4 is in the form of a bushing of increased diameter. The stop is pressed into the body of the body 1. The lift of the needle is h and = 1 mm. The developed needle head made it possible to increase the diameter of the rod 3, which transmits the tightening force of the injector spring 2 (P cp) to the needle, which increased the reliability of the spring-rod assembly.

Burmeister and Wein injectors are usually cooled with diesel fuel from a stand-alone system.

Rice. 6.4.5

In recent years, all high-power marine low-speed diesel engines Burmeister and Vine, as well as promising diesel engines MAN - Burmeister and Vine, are equipped with new nozzles of a unified design (see Fig. 6.4.5., 6).

The fundamental difference in this case is that the nozzle is not cooled. Normal operation of the injector at high heating temperatures of heavy fuel (105-120 °C) is ensured due to its central supply through channel 14. In this case, a symmetrical temperature field and equal temperature gradients along the cross section of the atomizer are obtained, and, consequently, equal working gaps in conjugated pairs ( in all other injector designs, where hot fuel and coolant are supplied on different sides of its body, an asymmetric temperature field is created).

The atomizer consists of a nozzle 10, a guide 8, a needle 7 and a shut-off valve 17 inside the needle. The direction of one-sided nozzle holes is ensured by fixing the nozzle with pin 5 (the body 1 of the nozzle is fixed with its pin at the attachment point, not shown in the drawing). Needle 7, having the shape of a glass at the top, perceives the force of tightening the spring 2 through the slider 13, into the cutouts of which the head of the spacer 15 with the central channel 14 enters. The lower shoulder of the spacer 15 limits the valve lift (h k \u003d 3.5 mm), and the upper shoulder - the needle lift (h and \u003d 1.75 mm).

The nozzle provides circulation of heated fuel when the engine is not running (during preparation for launch and during forced stops at sea), as well as in the period between adjacent injections, when the plunger pusher roller rolls around the cylindrical part of the washer.

When the engine is stopped, when the high-pressure fuel pump is in the zero supply position (the filling and discharge cavities are connected), the fuel priming pump at a pressure of 0.6 MPa supplies fuel to the injection fuel line and nozzle channel 14. “Since the spring 16 of the shut-off valve 17 has a tightening of 1 MPa, the valve does not rise, and the fuel passes through a small hole 18 into the needle cup and then upwards to the drain. Thus, during a stop of any duration, the entire injection system will be filled with fuel of working viscosity. This is extremely important for the reliable operation of the fuel equipment.

When the engine is running during the active stroke of the plunger, the discharge pressure almost instantly raises the shut-off valve 17, and the bypass hole 18 is closed. The fuel passes to the differential area of the needle 7 and raises the needle.

At the end of the active stroke of the plunger, the entire injection system is quickly unloaded through the working cavity of the pump, since there is no discharge valve in it. When the fuel pressure drops below the tightening pressure P ap. spring 2 seats needle 7, and at a pressure below 1 MPa, spring 16 lowers shut-off valve 17 into place. The plunger pusher roller goes to the top of the washer for a long time, and the injection system is again pumped with fuel until the next active stroke of the plunger.

In the considered feature of the new injector, a great advantage of the fuel equipment, since in any operating conditions it is constantly in the operating temperature mode, which is extremely important for guaranteeing reliability.

Practice has shown that during forced stops of ships at sea, during long stays in readiness, as well as during long modes of low speeds and maneuvers, heavy fuel cools down along the entire injection line, its viscosity increases. In such cases, after starting the engine or during sudden load surges, the injection pressure can increase significantly, and the hydraulic forces in the discharge line can reach a dangerous level. As a result, cracks can form in the high-pressure fuel pump housings and the walls of the injection fuel lines, break through their junctions with the pump and nozzle (especially when these places are threaded).

For fuel equipment with cooled injectors, there are several solutions aimed at maintaining the temperature regime of the injection system under the mentioned conditions: turning off the cooling of the injectors, supplying steam to the cooling channels, installing steam "satellites" along the entire (or part) of the injection fuel line, etc. However, all these solutions are significantly inferior to the nozzle with a symmetrical temperature field in terms of efficiency.

A positive factor in favor of uncooled injectors is that it eliminates the need to use a special cooling system (two pumps, a tank, pipelines, instrumentation and automation).

There are, however, disadvantages as well. The design of the nozzle is complex, multi-detailed. There are nine lapping points, and lapping requires special mandrels. In the fuel equipment, there is actually no pressure valve, since the shut-off valve 17 does not perform its functions: in the event of a sticking of the nozzle needle, fuel is pushed out of the injection system by gas pressure in the cylinder shortly after the end of the active stroke of the plunger. Experience shows that the cylinder switches itself off in this case.

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Ministry of Education and Science, Youth and Sports of Ukraine

"Odessa National Maritime Academy"

Course work

By discipline: Marine internal combustion engines

Fulfilled

Pisarenko A.V.

Checked:

prof. Gorbatyuk V.S.

Odessa 2012

Introduction

Long-term practice has shown that on all types of merchant and specialized fleet ships, as the main engines, we will get the advantage of using an internal combustion engine.

High efficiency in terms of specific fuel consumption, high effective efficiency, significant motor resource and reliable engine are the main reasons for the use of diesel in the marine fleet.

Along with the frequently used complex, which consists of a piston engine, gas turbines and compressors, on transport ships with powerful diesel installations. Most of the time, working in a constant full load mode at the transitions between ports, a combined type scheme with exhaust gas heat recovery in G.T.N. is widely used. and in the utilization boiler, which significantly increases the efficiency of the engine. If there is enough steam from the utilization boiler, a turbogenerator is additionally installed to provide the ship with electricity on the move, which saves fuel for the operation of the diesel generator.

Such diesel installations are equipped with remote control means, systems and devices for continuous monitoring of the operating parameters of the temperatures of the critical engine components of the coolant and oil, alarm protection systems with a record of all parameter disconnections from permissible limits on a control tape.

At present and in the near future, the main direction of development of marine diesel construction is to improve the working process of the engine aimed at increasing the efficiency in fuel and oil consumption, deep utilization of the heat of exhaust gases and cooling water, increasing the reliability of diesel engines in all operating modes, and improving the design and application , higher quality materials.

On the ships of the transport and specialized fleet, we will widely use the leading diesel-building companies, including: Burmeister and Wein (Denmark), MAN (F.R.G.), Sulzer (Switzerland), Buryansk Motor-Building Plant " (Russia).

To carry out the course project as a prototype engine, use the engine of the company "Burmeister and Wine" brand 5DKRN 62/140

1. Engine design data

The engine is two-stroke, with direct-flow valve scavenging, crosshead, reversible, supercharged, right-hand rotation, with 8 cylinders and an aggregate power of 10,000 hp. With.

The purge system when the engine is running in reverse, the exhaust valve opens at 83 lb.m.t. and closes at 63 after n.m.t. Inflating the gas turbine engine.

The purge system during forward operation has the following gas distributions. The exhaust valve opens at 89 b.p.m. closing at 57 after n.m.t. Exhaust valve opening angle at 146 purge ports at 76 turns of the crankshaft.

Air is supplied to the cylinder by a centrifugal supercharger through a tubular air cooler with ribs, a common welded receiver and under the piston cavities.

The fuel supply system of the engine is arranged as follows. Fuel priming pump - piston, two-cylinder, with a discharge pressure of 3-4 MPa. It is driven by a crank at the nose end of the crankshaft. Fine filters - with fine felt cartridges.

High pressure pump - spool type, adjustable at the end of the feed. The maximum injection pressure is 600 kPcm. The plunger has a diameter of 28 mm and a stroke of 42 mm. Cam washer - symmetrical profile, consisting of two halves.

The closed type nozzle is cooled by fuel. Force opening pressure 220 kPcm. The needle with a flat end has a lift of 0.7 mm, a nozzle with three holes with a diameter of 0.67 mm.

At the nose end of the bed there is a diesel fuel cooler, and in the heavy fuel system - a fuel heater with a thermostat.

Cylinder cooling system, exhaust valve - closed, double-circuit, driven by pumps from electric motors.

Fresh water is supplied to the cylinders under pressure! 8 atm. from the line and, having passed the covers and bodies of the exhaust valves, it is discharged at a temperature of 6065 ° C through the branch pipes into the line. Outboard water for cooling air coolers is supplied at a pressure of 0.8 atm. and discharged at a temperature of 40-45 °C through pipelines.

The circulating lubrication system is served by pumps driven by an electric motor. Oil for the crank mechanism, drive compartment of the thrust mechanism, drive compartment, thrust bearing and exhaust valve drive is supplied at a pressure of 1.8 atm. along the highway.

The cylinder liner is made of alloyed cast iron and has 18 purge windows 9.8 mm high with a total of 1008 mm. In the horizontal plane, the windows have a tangential direction. The sleeve is sealed along the jacket at the top by lapping the bearing surfaces, at the bottom - by one red-copper belt. Lubrication is supplied to the bushing mirror above the purge windows through two fittings with ball non-return valves. The cylinder cover made of heat-resistant alloy steel is sealed at the end of the sleeve by lapping, the cover contains an exhaust valve with an average diameter of 250 mm at a stroke of 66 mm, two nozzles, a safety valve and an indicator cock. From the cylinder to the cover, the cooling water passes to two pipes and through two pipes from the cover to the exhaust valve body of the piston - the engine is composite. The alloy steel head houses three top O-rings 10 mm high and 17 mm wide. The short guide is made of alloyed cast iron.

Welded displacer and radial holes in the cylindrical part of the piston head contribute to better heat dissipation from the walls to the oil. Oil is supplied through the tube. The 170 mm diameter carbon steel rod is attached to the piston head through the guide flange with studs. The rod is connected to the crosshead crosshead by the end annular surface by means of a guide cylindrical shank with a seagull. In the lower part of the rod, oil is supplied by a tube, sealed with a sleeve separating the supply cavity from the drain one. The multi-piece cast iron stem packing has two wiper rings and two O-rings.

The crosshead of the engine is double-sided, with 4 sliders made of cast steel, which are studded to the highlanders of a forged steel cross member. The working surfaces of the sliders are filled with babbitt. Connecting rod with detachable head and ball bearings made of cast steel and filled with babbitt. Head bearings with a diameter of 280 mm and a width of 170 mm have two connecting rod bolts and a Motylev diameter of 400 mm with a width of the upper half of 240 mm and a width of the lower head of the bearing of 170 mm have two full connecting rod bolts. The bolts are made of alloy steel and do not have centering belts. The rod of the connecting rod with a diameter of 190 mm with a rigid head without a fork is hollow, made of alloy steel. The connecting rod rod and bearings have holes for supplying oil from the crank bearing to the head ones.

Composite crankshaft: frame and crank journals made of carbon steel have a diameter of 400 mm, a length of 254 mm; cast steel rails 660 mm wide and 185 mm thick; hollow necks are closed at the ends of the cover and with screws. Due to the conditions of lubrication and strength, the radial holes in the crankpins are offset from the plane of the crankshaft.

According to the engine balancing conditions, some cheeks are cast with counterweights. The engine thrust bearing is single-comb, with six forward and reverse swinging thrust segments, which are located in 2 sectors and are fixed in a welded housing with two covers. The turning device includes an electric motor connected to the wheel on the thrust shaft through two worm gears.

From the sump at a temperature of 45-52 ° C, the oil is discharged into a waste tank.

The lubrication of the bushings of the working cylinders is carried out from lubricators with a camshaft drive. The bearings of gas turbochargers are lubricated by a separate system with a gear pump driven by an electric motor.

The drive of the camshaft of the fuel pumps and the camshaft of the exhaust valves is made by a single chain with a pitch of 89 mm. From the eccentric on the exhaust camshaft, an indicator drive for each cylinder, consisting of a lever and a crown rod, receives movement. The cam roller of the spool air distributor in a block design has a chain drive from the camshaft, fuel pumps.

The engine control station has a start-reversing and fuel handle. The engine is started by compressed air pressure 30 kg / cm3 with simultaneous fuel supply. The change in the direction of rotation of the engine shaft is carried out automatically after the air distributor is reversed to the starting states by turning the crankshaft relative to the blocked camshafts of the fuel pumps and exhaust valves.

The following are installed at the control station: a mechanical tachometer, a rotation direction indicator, a total engine speed counter, pressure gauges for oil, fuel, purge air, fresh and sea water, oil and exhaust gases. At the control post there are also remote tachometers for each gas turbocharger and a flywheel for shut-off starting air.

The foundation frame, the bed with A-shaped blades, the stand, consisting of two sections, and the skeleton, the drive compartment are of welded construction.

The frame is connected to the bed with short bolts. Double-sided cast-iron parallels are fixed on the racks. The crankcase compartments are closed with removable steel shields with viewing windows and safety lamellar plates loaded with springs. The cylinder block consists of separate large shirts. To increase the speed of water in the cooling cavity, the flow area has been reduced - especially in the region of the upper part of the sleeve. The shirts have hatches for inspecting the cooling cavities. Short alloy steel tie-downs connect the cylinder jackets through a pedestal to the upper reinforced crankcase riser plate. The connections are placed in the cavities of the connector of the shirts.

2. Thermal calculation

The main task of the verification calculation is to evaluate the parameters of the operating cycle in the operating mode of the engine. In this case, the values of the parameters controlled in operation using standard devices are used.

2.1 Filling process

The air pressure at the compressor inlet.

P0? = P0-Drf kgf/cm (1)

Where, P0 is barometric pressure, 720 mmHg (given)

DRF-pressure drop on air filters STC, 93 mm w.c. (specified)

1mm Hg=0.00136 kgf/cm

1mm water column=0.0001 kgf/cm

P0?=720*0.000136-95* 0.0001=0.96

Air pressure after compressor

pk \u003d rs + Drx kgf / cm (2)

where, ps - air pressure in the receiver (after the refrigerator), 1.42 kgf / cm

drx - pressure drop across air coolers 250 mm w.c. (specified)

pk=1.6+140*0.0001=1.614

Compressor pressure ratio

p k \u003d pk / P0? (3)

p k=1.614/0.96=1.68

Cylinder pressure at the end of filling

For two-stroke engines with direct-flow-valve scavenging and from the Sulzer contour-loop.

pa=(0.96-1.05) ps (4)

For calculation we accept 1.01

Ra=1.01*1.6=1.616

Charge air temperature in the receiver (after the cooler)

Tk=T? c *pk ^(nk-1/nk) K (5)

where is T? с= Т0= 273 +t0- air temperature at the compressor inlet

nk is the compression polytropic index in the compressor. For centrifugal pumps with cooled housing nk=1.6-1.8. For calculation we accept nk=1.7

T? c=273+35=308

Tk \u003d 308 * 1.616 ^ (1.7-1 / 1.7) \u003d 375.76

Air temperature in the receiver

Тs=273+ tz.v. +(15-20) K (6)

where ts.v - sea water temperature (ts.v = 17С)

Тs=273+10+17=300

Air temperature in the working cylinder, taking into account heating (Dt) from the walls of the combustion chamber.

T?s \u003d Ts + Dt K (7)

Where Dt=5-10C for calculation we accept Dt=7C

Temperature of the mixture of air and residual gases at the end of filling

Ta \u003d (T? s + r Tr) / 1 + r K (8)

where r is the coefficient of residual gases. For two-stroke with direct-flow valve purge r = 0.04-0.08.

For calculation we accept r=0.06

Tr-temperature of residual gases Tr=600-900. For calculation we accept Tr=750

Ta=(307+0.06 *750) /1+0.06=332

Filling ratio related to effective piston stroke

h n= (/ -1)* (pG/ps)* (Ts/Ta)*(1/1+r) (9)

where is the value of the compression ratio. For low-speed engines = 10-13. For calculation we accept =12

h n=(12/12-1)*(1.616/1.6)*(301/332)*(1/1+0.06)=0.94

Filling ratio related to total piston stroke.

h? n= s n(1- s) (10)

where s is the relative lost piston stroke. For engines with straight-valve purge s=0.08-0.12. For calculation we accept s=0.1

h? n=0.94(1-0.1)=0.85

Full working volume of the cylinder.

V?s= рD^2/4*S m

V?s=0.785*0.62^2*1.4=0.24

Charge air density

s=10^4*Ps/R*Ts kg/m

where R \u003d 29.3 kgm / kg deg (287 J / kg rad) - gas constant

s=10^4*1.6/29.3*301=1.8

The charge of air, referred to the full working volume of the cylinder.

(kg/cycle) (11)

where d is the moisture content of the air, determined depending on temperature and relative humidity (Table 1)

2.2 Compression process

For low and medium speed engines n1 =1.34+1.38. For calculation we take 1.36

First approximation n1 =1.36

Second approximation n1 =1.377

We accept n1 = 1.375

Pressure at the end of the compression process.

Rc \u003d p a * kgf / cm (13)

Pc= 1.616-12" 377 =49.48

Temperature at the end of the compression process.

Tc \u003d Ta * K (14)

Tc \u003d 333 -12 0 - 377 \u003d 849.7

For reliable self-ignition of fuel, Tc must be at least 480 + 580 "C or 753 + 853" K.

2.3 Combustion process

Maximum combustion pressure.

p: \u003d rs * l kgf / cm (15)

where, l \u003d Pz / Pc - the degree of pressure increase. For low-speed engines l = 1.2 / 1.35. For calculation we accept l \u003d 1.3

pz = 49.48 *1.3 = 64.32

The maximum combustion temperature is determined from the combustion equation, which can be reduced to the form.

ATz 2 + VTz -C \u003d o

Solving the quadratic equation, we get:

where, zhz - coefficient of heat utilization by the moment of expansion start; For low-speed engines, z = 0.80 0.86.

For calculation we accept zhz=0.83

Net calorific value

Qn \u003d 81С + 300Н -26 (0-S) - 6 (9 Н + W) kcal / kg, (17)

where, C, H, 0, W, - the content of carbon, hydrogen, sulfur and water% For the calculation, we are given F-12 naval fuel oil. From table 2 we take C=86.5%, H=12.2%, S=0.8%, O=0.5%, Qn=9885 kcal/kg.

The amount of air theoretically required for the complete combustion of 1 kg of fuel:

in volume units

Lo= kmol/kg (18)

in units of mass

Go=Lo *mo kg/kg (19)

where mo \u003d 28.97 kg / kmol - mass of 1 kmole of air

G0 = 0.485 * 28.97 = 14

The amount of air actually supplied to the cylinder for the complete combustion of 1 kg of fuel:

in volume units

L=d*L0 kmol/kg (20)

in units of mass

G =d* G0 kg/kg (21)

Where d- coefficient of excess air during fuel combustion. For slow speed engines d= 1.8 + 2.2. For calculation we take d=2.

L = 2*0.485 = 0.97

Theoretical coefficient of molecular change. (22)

The actual coefficient of molecular change.

Average molar isochoric heat capacity of the mixture of fresh air charge and residual gases at the end of the compression process.

(mC v) s cm \u003d (mCv) s woz \u003d 4.6 + 0.0006 * Tc kcal / kmol deg (24)

(mS v) s cm = 4.6 + 0.0006-849.7 = 5.11

The average molar isobaric heat capacity of a mixture of "pure" combustion products with excess air and residual gases remaining in the cylinder after combustion.

Let us substitute the obtained values into equation (25).

2.4 Expansion process

Degree of pre-expansion.

The degree of subsequent expansion.

The average exponent of the polytropic expansion z2 is determined by the method of successive approximation from the equation:

Since we do not need greater accuracy when calculating s2 according to formula (28), then the value of s2 for low-speed engines is s2 = 1.27/ 1.29, we choose s2 = 1.28

pressure at the end of expansion. (29)

pb \u003d 64.32 * 1 / 6.59 1 "28 \u003d 5.75

temperature at the end of expansion. (thirty)

2.5 Gas parameters in the exhaust tract

The average gas pressure behind the exhaust bodies of the cylinders.

pr- = rs-zhn kgf/cm (31)

where n=(0.88/0.96) is the coefficient of pressure loss during purge in the inlet and outlet organs. For calculation, we take zhn = 0.92.

Pr=1.6*0.92 = 1.47

Average gas pressure in front of the turbines

PT=Pr*zhr kgf/cm (32)

where, sg = 0.97 + 0.99) is the coefficient of pressure loss when blowing in the exhaust from the cylinder to the turbines. For calculation, we accept zhg = 0.98.

PT = 1.47 * 0.98 = 1.44

The average temperature of gases in front of the turbines. (33)

where, qg = (0.40 + 0.45) is the relative heat loss with the exhaust gases in front of the turbines. For calculation we accept qr=0.43. c a - purge coefficient. For two-stroke with GTN ca = 1.6 / 1.65. For calculation, we accept ca = 1.63.

C Р g = (0.25 / 0.26) - the average isobaric heat capacity of gases. For calculation, we take Сpr=0.26.

2.6 Energy and economic indicators of the engine

The average indicator pressure of the theoretical cycle, related to the useful stroke of the piston, according to the Mazing-Sinetsky formula.

Pн=kgf/ (34)

The average indicated pressure of the theoretical cycle, referred to the full stroke of the piston.

Average indicator pressure of the estimated actual cycle.

Where, is the rounding factor of the chart. For two-stroke with direct-flow valve purge. For calculation we take

P=12.14*0.97=11.77

Indicative engine power in operating mode.

Where, z is the tact factor. For two-stroke engines z=1

Rated indicated motor power.

Where, the mechanical efficiency of the engine at nominal mode. For two-stroke

For calculation we take

The mechanical efficiency of the engine is nV in operating mode.

Average effective pressure in operating mode.

Pc=11.77-0.92=10.82

Effective engine power in operating mode.

Nc=Ni*zm hp (41)

Nс=7439 -0.92* 6843.88

Specific indicator fuel consumption in operating mode.

kg/l.s.h. (42)

Specific effective fuel consumption in the operating mode.

kg/l.s.h. (43)

Hourly fuel consumption in operating mode.

Cyclic fuel supply in operating mode.

Indicator efficiency in operating mode.

Effective efficiency in operating mode.

h= 0.49-0.92 = 0.45

2.7 Byindicator diagram structure

We take the volume of the cylinder Va on a scale equal to the segment A = 120mm.

On the abscissa axis, we plot the found volumes. Let's define the scale of ordinates:

mm/kgf/cm

B - the length of the segment is 1.3-1.6 times less than segment A. We accept B 1.5 times. H=80mm.

We determine the intermediate volumes and their corresponding compression and expansion pressures. The calculation is made in tabular form.

According to the table, we plot characteristic points on the diagram and build compression and expansion polytropes. The constructed diagram is theoretical (calculated).

To build the proposed indicator diagram, we round off the corners of the theoretical diagram at points C. Z and Z. The actual release process begins at point b, the position of which on the diagram can be found using the F.A. diagram. Brix.

Crank radius in drawing scale.

Brix correction.

where l is the simplest crank mechanism. We accept l \u003d 0.25. The angle (Ci of the beginning of the opening of the exhaust valve is taken equal to 90 P.K.V. to N.M.T.

From point O, using a protractor from the abscissa axis, we set aside the angle (q, draw a vertical to the intersection with the expansion curve and find the position of the point b. > Points b and a are connected by a curve.

Table 1

3. Dynamic calculation of the engine

3. 1 Problems of kinematic and dynamic analysis of motion curvestud-rod mechanism (KShM)

Parts of an internal combustion engine during its operation are under the influence of various forces. The most responsible node of the internal combustion engine is the crankshaft.

The following forces act in the crankshaft engine during its operation:

1) Gas pressure on the piston:

where: r g - gas pressure in the engine cylinder, MPa;

F- area of the piston bottom With () ;

2) Inertia of translationally moving masses

where: m pd - mass of translationally moving parts, kg;

a - piston acceleration m/ ;

3) Gravity of translationally moving masses:

4) Forces of friction.

They do not lend themselves to an exact theoretical definition and are included in the mechanical losses of the engine. The forces of weight (gravity) are small compared to other forces and therefore they are usually not taken into account in approximate calculations.

Total moving force:

Since we do not yet know the mass of the parts of the designed internal combustion engine, then for the calculation they use the specific forces related to the piston unit per cm 2 (m 1). Thus:

3. 2 Definition of driving force

Construction method

The indicator diagram, built on the basis of the calculation of the working process, gives the dependence of p g on the piston stroke. For further calculations, it is necessary to link the forces acting on the internal combustion engine with the angle of rotation of the crankshaft.

Parallel to the abscissa axis of the indicator diagram, constructed on the basis of the results of calculating the parameters of the ICE cycle, a straight line AB is drawn. The segment AB is divided by the point O in half, and from this point the radius OA describes a semicircle. From the center of the circle (point O) towards the NDC, a segment is laid off 00 1 \u003d 0.5 g - the Brix correction, where g \u003d OA (to maintain scale).

Constant KShM;

where: R - crank radius;

L is the length of the connecting rod between the bearing axes.

The value of I is taken within the following limits:

For low speed crosshead engines 1/4.2 - 1/3.5;

In our case, we take X = 0.25.

From O1 (the Brix pole), a second circle (larger than the first) is described with an arbitrary radius and divided into equal parts (usually after 5-15 °). Rays are drawn from the Brix pole through the division points of the second circle.

To construct a diagram, we accept -r.c.v.

For the expanded indicator diagram Р g = (a) we take the scale along the ordinate axis М ord = 10 mm. I MPa and along the abscissa M abts = 20 degrees, 1 cm.

Because the accepted scale along the y-axis is 1.5 times smaller than the scale of the p-V diagram, therefore the ordinates taken from it are divided by 1.5 and set aside for resp. and on the diagram P r = (a).

To construct a diagram of the forces of inertia R g = ѓ (a) we take t pd = 7000

The diagram of moving forces is built by summing the ordinates of the diagrams P, = / (a) and P s = / (a) taking into account their signs.

3. 3 Plotting shear forces

1. How to plot a diagram for one cylinder:

We build the diagram of tangential forces on the same scale as the diagram of moving forces: Mabts = 20 degrees / cm, M ord = 10 mm / MPa.

Compile table 3. Trigonometric function : determine for = 1 / 4 from table 2; R d - based on fig. 3 in mm.

The tangential force (tangential) is determined by the formula:

Ra is the driving force (see above).

The trigonometric function, which is determined according to Table 3, depending on a p.c.v. And:

The angle of deviation of the connecting rod axis from the axis of the cylinder.

Certain values - , P 0 , P K are summarized in tables 3 and 4, on the basis of which a diagram of tangential forces for one cylinder is constructed (Fig. 3a).

Table 3


Working stroke (expansion)

Table 4. Calculation of the inertial forces of translationally moving masses Р and = ѓ(a) MPa

	Engine 5 DKRN 62/140

2. Method for constructing a summary diagram of tangential forces.

The total diagram of tangential forces is built on the same scale as the diagram of tangential forces of one cylinder (Fig. 36)

Determine the specific resistance force

And the average tangential force

The scale of the ordinate axis = 10 mm / MPa, therefore

Diagramming error

What is allowed

3. 4 Flywheel calculation

marine engine connecting rod flywheel

To calculate the flywheel, at the beginning, the values \u200b\u200bof uneven rotation of the crankshaft are set:

Determine the area scale of the summary chart

Regarding

We plan the area of excess work:

Determine the specific excess work:

Then the redundant work:

where: R - crank radius (m); moment of inertia of the moving parts of the engine and flywheel:

Moment of moving parts of the internal combustion engine:

Calculate the moment of inertia of the flywheel:

4=1483.08(kg/)

We accept the reduced diameter of the flywheel :

where: S - overall dimensions; prototype engine, m; Then:

We calculate the mass of the rim:

Determine the total mass of the flywheel:

0.88 -= 0.8 - 7 3 5.21 = 572.2 (kg)

We determine the dimensions of the flywheel rim from the expression:

Where: R- density. For steel p = 7800(kg/m) . b and h are the width and thickness of the rim, respectively, m. We take the thickness of the rim equal to h = 0.2 m, then:

Flywheel maximum diameter:

2.88 + 0.04 = 2.92 (m)

Checking the circumferential speed of the flywheel rim:

The resulting value is valid for the designed engine.

Listliterature

1. Pointing method

2. Mikheev V.G. "Main ship power plants". Guidelines for course design for the nautical and arctic schools of the Minimorflot. M., TsRIL "Morflot", 1981, 104s.

3. Gogin A.F. "Ship diesels", basics of theory, design and operation. Textbook for river schools and technical schools of water transport: 4th ed. Revised And supplemented - M., Transport, 1988. 439s.

4. Lebedev O.N. "Ship power plants and their operation". Textbook for universities water. transp. - M.: Transport, 1987 - 336s.

5. A.A. Foka, Mitryushkin Yu.D. "Maintenance of the ship in flight"

6. A.N. Neyelov "Rules for the technical operation of ship technical equipment", Moscow 1984. - 388s.

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Design descriptionengine

Marine diesel of the company "MAN - Burmeister and Wein" (MAN B&W Diesel A / S), brand L50MC / MCE - two-stroke single-acting, reversible, crosshead with gas turbine pressurization (with constant gas pressure in front of the turbine) with built-in thrust bearing, cylinder arrangement in-line , vertical.

Cylinder diameter - 500 mm; piston stroke - 1620mm; purge system - direct-flow valve.

Diesel effective power: Ne = 1214 kW

Rated speed: n n \u003d 141 min -1.

Effective specific fuel consumption in nominal mode g e = 0.170 kg/kWh.

Diesel overall dimensions:

Length (along the fundamental frame), mm 6171

Width (along the fundamental frame), mm 3770

Height, mm. 10650

Weight, t 273

The cross section of the main engine is shown in fig. 1.1. Coolant - fresh water (in a closed system). The temperature of fresh water at the outlet of the diesel engine in the steady state is 80...82°C. The temperature difference at the inlet and outlet of the diesel engine is no more than 8...12°C.

The temperature of the lubricating oil at the diesel inlet is 40...50 °C, at the diesel outlet 50...60°C.

Average pressure: Indicator - 2.032 MPa; Effective -1.9 MPa; The maximum combustion pressure is 14.2 MPa; Purge air pressure - 0.33 MPa.

The assigned resource before overhaul is at least 120,000 hours. The service life of a diesel engine is at least 25 years.

The cylinder head is made of steel. An exhaust valve is attached to the central hole with four studs.

In addition, the cover is equipped with drillings for nozzles. Other drillings are for indicating, safety and starting valves.

The upper part of the cylinder liner is surrounded by a cooling jacket installed between the cylinder head and the cylinder block. The cylinder bushing is attached to the top of the block with a cover and centered in the bottom hole inside the block. The tightness against leakage of cooling water and scavenging air is ensured by four rubber rings embedded in the grooves of the cylinder liner. On the lower part of the cylinder liner between the cavities of the cooling water and scavenging air, there are 8 holes for fittings for supplying lubricating oil to the cylinder.

The central part of the crosshead is connected to the head bearing journal. The cross beam has a hole for the piston rod. The head bearing is equipped with liners that are filled with babbitt.

The crosshead is equipped with drillings for supplying oil supplied through a telescopic tube partly to cool the piston, partly to lubricate the head bearing and guide shoes, and also through the hole in the connecting rod to lubricate the crank bearing. The central hole and the two sliding surfaces of the crosshead shoes are filled with babbitt.

The crankshaft is semi-compound. The oil for the frame bearings comes from the main lube oil line. The thrust bearing is used to transfer the maximum thrust of the screw through the screw shaft and intermediate shafts. The thrust bearing is installed in the aft section of the fundamental frame. The lubricating oil for lubricating the thrust bearing comes from the pressure lubrication system.

The camshaft consists of several sections. Sections are connected by means of flange connections.

Each engine cylinder is equipped with a separate high pressure fuel pump (TNVD). The operation of the fuel pump is carried out from the cam washer on the camshaft. The pressure is transmitted through the pusher to the fuel pump plunger, which is connected to the injectors mounted on the cylinder head by means of a high pressure pipe and a junction box. Fuel pumps - spool type; nozzles - with a central supply of fuel.

Air is supplied to the engine by two turbochargers. The TC turbine wheel is driven by the exhaust gases. A compressor wheel is mounted on the same shaft as the turbine wheel, which takes air from the engine room and supplies air to the cooler. A moisture separator is installed on the cooler body. From the cooler, air enters the air receiver through open non-return valves located inside the charge air receiver. Auxiliary blowers are installed on both ends of the receiver, which supply air past the coolers in the receiver with non-return valves closed.

Rice. Cross section of the L50MC/MCE engine

The engine cylinder section consists of several cylinder blocks that are anchored to the base frame and crankcase. Between themselves, the blocks are connected along vertical planes. The block contains cylinder bushings.

The piston consists of two main parts, the head and the skirt. The piston head is bolted to the top ring of the piston rod. The piston skirt is attached to the head with 18 bolts.

The piston rod is drilled through for the cooling oil pipe. The latter is attached to the top of the piston rod. Further, the oil enters through a telescopic tube to the crosshead, passes through drilling in the base of the piston rod and piston rod to the piston head. Then the oil flows through the drilling to the bearing part of the piston head to the piston rod outlet pipe and then to the drain. The rod is attached to the crosshead with four bolts through the base of the piston rod.

The choice of fuel and oil with an analysis of the influence of their characteristics on pAbot

Used grades of fuels and oils

Applied fuels

In recent years, there has been a steady deterioration in the quality of marine heavy fuels associated with deeper oil refining and an increase in the proportion of heavy residual fractions in the fuel.

Marine ships use three main groups of fuels: low-viscosity, medium-viscosity and high-viscosity. Of the low-viscosity domestic fuels, distillate diesel fuel L has received the greatest use on ships, in which the content of mechanical impurities, water, hydrogen sulfide, water-soluble acids and alkalis is not allowed. The sulfur limit for this fuel is 0.5%. However, for diesel fuels produced from high-sulfur oil according to specifications, the sulfur content is up to 1% and higher.

Medium-viscosity fuels used in marine diesel engines include diesel fuel and marine fuel oil grade F5.

The group of high-viscosity fuels includes the following grades of fuels: DM brand motor fuel, M-0.9 marine fuel oils; M-1.5; M-2.0; E-4.0; E-5.0; F-12. Until recently, the main criterion for ordering was its viscosity, by the value of which we roughly judge other important characteristics of the fuel: density, coking capacity, etc.

The viscosity of the fuel is one of the main characteristics of heavy fuels, since the processes of fuel combustion, the reliability of operation and durability of fuel equipment, and the possibility of using fuel at low temperatures depend on it. In the process of preparing the fuel, the required viscosity is ensured by its heating, since the quality of atomization and the efficiency of its combustion in the diesel cylinder depend on this parameter. The viscosity limit of the injected fuel is governed by the engine maintenance instructions. The rate of sedimentation of mechanical impurities, as well as the ability of the fuel to exfoliate from water, largely depends on the viscosity. With an increase in the viscosity of the fuel by a factor of 2, all other conditions being equal, the time of particle settling also increases by a factor of two. The viscosity of the fuel in the settling tank is reduced by heating it. For open systems, the fuel in the tank may be heated to a temperature not less than 15°C below its flash point and not higher than 90°C. Heating above 90°C is not allowed, as in this case it is easy to reach the boiling point of water. It should be noted that the emulsion water on the value of viscosity. With an emulsion water content of 10%, the viscosity can increase by 15-20%.

Density characterizes the fractional composition, volatility of the fuel and its chemical composition. High density means a relatively higher ratio of carbon to hydrogen. Density is of greater importance when refining fuels by separation. In a centrifugal fuel separator, the heavy phase is water. To obtain a stable interface between fuel and fresh water, the density should not exceed 0.992 g/cm 3 . The higher the density of the fuel, the more difficult it becomes to control the separator. A slight change in viscosity, temperature and density of the fuel leads to the loss of fuel with water or deterioration in fuel cleaning.

Mechanical impurities in fuel are of organic and inorganic origin. Mechanical impurities of organic origin can cause the plungers and nozzle needles to hang in the guides. Getting at the moment of planting valves or nozzle needle on the saddle, carbons and carboids stick to the ground surface, which also leads to disruption of their work. In addition, carbons and carboids get into diesel cylinders, contribute to the formation of deposits on the walls of the combustion chamber, piston and in the exhaust tract. Organic impurities have little effect on the wear of fuel equipment parts.

Mechanical impurities of inorganic origin are abrasive particles by their nature and, therefore, can cause not only freezing of moving parts of precision pairs, but also abrasive destruction of rubbing surfaces, seating lapped surfaces of valves, nozzle needle and atomizer, as well as nozzle holes.

Coke residue - mass fraction of carbon residue formed after combustion in a standard instrument of the tested fuel or its 10% residue. The value of the coke residue characterizes the incomplete combustion of the fuel and the formation of soot.

The presence of these two elements in the fuel is of great importance as a cause of high temperature corrosion on the hottest metal surfaces, such as exhaust valve surfaces in diesel engines and superheater tubes in boilers.

With the simultaneous content of vanadium and sodium in the fuel, sodium vanadates are formed with a melting point of approximately 625 °C. These substances cause a softening of the oxide layer that normally protects the metal surface, this causes the destruction of grain boundaries and corrosion damage to most metals. Therefore, the sodium content should be less than 1/3 of the vanadium content.

Residues from the fluid catalytic cracking process may contain highly porous aluminosilicate compounds which can cause severe abrasion damage to fuel system components as well as pistons, piston rings and cylinder liners.

Applicable oils

Among the problems of reducing the wear of internal combustion engines, the lubrication of the cylinders of marine low-speed engines occupies a special place. In the process of fuel combustion, the temperature of the gases in the cylinder reaches 1600 °C and almost a third of the heat is transferred to the colder walls of the cylinder, the piston head and the cylinder cover. The downward movement of the piston leaves the lubricating film unprotected and exposed to high temperatures.

The products of oil oxidation, being in the zone of high temperatures, turns into a sticky mass covering the surfaces of pistons, piston rings and cylinder liner like a varnish film. Lacquer deposits are poor thermal conductors, so heat dissipation from a varnished piston deteriorates and the piston overheats.

cylinder oil must meet the following requirements:

- have the ability to neutralize acids resulting from fuel combustion and protect working surfaces from corrosion;

- prevent the deposition of deposits on pistons, cylinders and windows;

- have a high strength of the lubricating film at high pressures and temperatures;

- do not give combustion products harmful to engine parts;

- have stability during storage in ship conditions and insensitivity to water

Lubricating oils must meet the following requirements:

- to have viscosity, optimum for the given type;

- have good lubricity;

- be stable during operation and storage;

- have, if possible, a minimal tendency to soot and varnish formation;

- must not have a corrosive effect on parts;

- must not foam or evaporate.

To lubricate the cylinders of crosshead diesel engines, special cylinder oils for sour fuels with detergent and neutralizing additives are produced.

Due to the significant forcing of diesel engines by supercharging, the problem of increasing the engine life can be solved only by choosing the optimal lubrication system and the most effective oils and their additives.

Choice of fuel and oils

Indicators	Standards for stamps
	Main fuel	Reserve fuel
			L (summer)
Viscosity at 80?C kinematic
Viscosity at 80?С conditional
			absence
			absence

low-sulphurous
sulphurous
Flash point, ?С
Pour point, ?С
Coking capacity, % mass

Density at 15? С, g/mm 3
Viscosity at 50?С, cst
Ash content, % mass
Viscosity at 20?С, cst
Density at 20? C, kg / m 3




Elf BP Castrol Chevron Exxon Mobile Shell	Atlanta Marine D3005 Energol OE-HT30 Marine CDX30 Veritas 800 Marine Exxmar XA Alcano 308 Melina 30/305	Talusia XT70 CLO 50-M

Technical use of marine diesel engines

marine diesel engine gas turbine

Preparation of the diesel plant for operation and diesel start-up

Preparation of a diesel plant for operation should ensure that diesel engines, service mechanisms, devices, systems and pipelines are brought into a condition that guarantees their reliable start-up and subsequent operation.

Preparation of the diesel engine for operation after disassembly or repair should be carried out under the direct supervision of the mechanic in charge of the diesel engine. In doing so, you need to make sure that:

1. the weight of the disassembled connections are assembled and securely fastened; pay special attention to locking nuts;

2. the necessary adjustments have been made; special attention should be paid to the installation of zero supply of high pressure fuel pumps;

3. all regular control and measuring devices are installed in place, connected to the controlled environment and are not damaged;

4. diesel systems are filled with working media (water, oil, fuel) of the appropriate quality;

5. fuel, oil, water and air filters are clean and in good condition;

6. when pumping oil with open crankcase shields, lubricant flows to bearings and other lubrication points;

7. protective covers, shields and casings are in place and securely fastened;

8. pipelines of the fuel, oil, water and air systems, as well as the working cavities of the diesel engine, heat exchangers and auxiliary mechanisms do not have gaps in working media; special attention should be paid to the possibility of leakage of cooling water through the seals of the cylinder bushings, as well as the possibility of fuel, oil and water getting into the working cylinders or into the diesel purge (suction) receiver;

9. The diesel injectors were checked for the density and quality of the fuel spray.

After performing the checks listed above, the operations provided for preparing the diesel installation for operation after a short stop (see paragraphs 1.3-1.9.11) must be performed.

The preparation of a diesel installation for operation after a short stop, during which work related to disassembly was not performed, should be carried out by the mechanic on duty (of the main installation - under the supervision of a senior or second mechanic) and include the operations provided for in paragraphs. 1.4.1--1.9.11. It is recommended to combine various preparatory operations in time.

In case of an emergency start, the preparation time can only be shortened by warming up.

Oil system preparation

It is necessary to check the oil level in the waste tanks or in the crankcases of the diesel engine and gearbox, in the oil collectors of turbochargers, oil servomotors, lubricators, speed controller, thrust bearing housing, in the camshaft lubrication tank. Top up with oil if necessary. Drain the sludge from the lubricators and, if possible, from the oil sump tanks. Replenish manual and wick lubricators, cap lubricators.

You should make sure that the devices for automatic replenishment and maintenance of the oil level in tanks, lubricators are in good condition.

Before cranking the diesel engine, it is necessary to supply oil to the working cylinders, cylinders of scavenging (boost) pumps and other lubricating lubrication points, as well as to all manual lubrication points.

Oil filters and oil coolers should be prepared for operation, valves on the pipelines should be set to the working position. Starting a diesel engine and its operation with faulty oil filters is prohibited. Remote controlled valves must be tested in action.

If the oil temperature is below the recommended operating instructions, it must be heated. In the absence of special heating devices, the oil is heated by pumping it through the system during the diesel engine warm-up (see clause 1.5.4); the oil temperature during heating should not exceed 45°C.

It is necessary to prepare for operation and start up independent oil pumps of the diesel engine, gearbox, turbochargers or pump the diesel engine with a hand pump. Check the operation of the means of automated (remote) control of the main and standby oil pumps, bleed air from the system. Bring the pressure in the lubrication and cooling systems of the pistons to the working pressure while turning the diesel engine with a barring device. Verify that all system gauges are reading and that there is flow in the sight glasses. Pumping with oil should be carried out during the entire time of diesel preparation (for manual pumping - before cranking and immediately before starting).

It is necessary to make sure that the emergency light signals disappear when the controlled parameters reach the operating values.

Preparing the water cooling system

It is necessary to prepare coolers and water heaters for operation, install valves and taps on pipelines in the working position, test the operation of remotely controlled valves.

The water level in the expansion tank of the fresh water circuit and in the tanks of the independent piston and nozzle cooling systems must be checked. Top up the systems with water if necessary.

It is necessary to prepare for operation and start up independent or standby fresh water pumps for cooling cylinders, pistons, nozzles. Check the operation of the means of automated (remote) control of the main and standby pumps. Bring the water pressure to the working level, release air from the system. The diesel should be pumped with fresh water during the entire time of diesel preparation.

It is necessary to warm up the fresh cooling floor with available means to a temperature of about 45°C at the inlet. The rate of heating should be as slow as possible. For low-speed diesel engines, the warm-up rate should not exceed 10°C per hour, unless otherwise indicated in the operating instructions.

To check the sea water system, start the main sea water pumps, check the system, including the operation of the water and oil temperature regulators. Stop the pumps and restart them immediately before starting the diesel engine. Avoid prolonged pumping of oil and water coolers with outboard water.

Make sure that the light alarms disappear when the controlled parameters reach the operating values.

Fuel system preparation

It is necessary to drain the sediment from the service fuel tanks, check the fuel level and, if necessary, replenish the tanks.

Fuel filters, viscosity regulator, fuel heaters and coolers must be prepared for operation.

It is necessary to set the valves on the fuel pipeline to the working position, to test the remotely controlled valves in operation. Prepare for operation and start up autonomous pumps for fuel priming and injector cooling. After raising the pressure to the working one, make sure that there is no air in the system. Check the operation of the means of automated (remote) control of the main and standby pumps.

If during the parking period, work was carried out related to the disassembly and emptying of the fuel system, the replacement or disassembly of high-pressure fuel pumps, injectors or injector pipes, it is necessary to remove air from the high-pressure system by pumping the pumps with the injector deaeration valves open or in another way.

For diesel engines with hydraulic shut-off nozzles, it is necessary to check the hydraulic mixture level in the tank and bring the hydraulic mixture pressure in the system to the working pressure, if this is provided for by the system design.

If the diesel engine is structurally adapted to operate on high-viscosity fuel, including starting and maneuvering, and has been stopped for a long time, it is necessary to ensure gradual heating of the fuel system (tanks, pipelines, high-pressure fuel pumps, injectors) by turning on heating devices and continuous circulation of the heated fuel. Before trial runs of the diesel engine, the fuel temperature must be brought to a value that provides the viscosity necessary for high-quality atomization (9--15 cSt), the fuel heating rate must not exceed 2 ° C per minute, and the fuel circulation time in the system must be at least 1 hour unless otherwise stated in the instruction manual.

When starting a diesel engine on low-viscosity fuel, it is necessary to prepare in advance for its transfer to high-viscosity fuel by turning on the heating of service and settling tanks. The maximum fuel temperature in tanks must be at least 10°C below the flash point of fuel vapors in a closed cup.

When replenishing service tanks, the fuel in front of the separator must be heated to a temperature not exceeding 90 ° C

Fuel heating to a higher temperature is allowed only if there is a special regulator for accurate temperature maintenance.

Preparation of the start-up, purge, pressurization, exhaust system

It is necessary to check the air pressure in the starting cylinders, blow condensate and oil out of the cylinders. Prepare for operation and start the compressor, make sure it is working properly. Check the operation of automated (remote) control of compressors. Fill cylinders with air to nominal pressure.

Stop valves on the way from the cylinders to the stop valve of the diesel engine should be opened smoothly. It is necessary to blow out the starting pipeline with the diesel shut-off valve closed.

It is necessary to drain water, oil, fuel from the purge air receiver, intake and exhaust manifolds, under-piston cavities, air cavities of gas air coolers and air cavities of boost turbochargers.

All locking devices of the diesel gas outlet must be open. Make sure the diesel exhaust pipe is open.

Shafting preparation

It is necessary to make sure that there are no foreign objects on the shafting, and also that the shafting brake is released.

The stern tube bearing should be prepared for operation by providing it with lubrication and cooling with oil or water. For stern tube bearings with an oil lubrication and cooling system, check the oil level in the pressure tank (if necessary, fill it to the recommended level), as well as the absence of oil leaks through the sealing glands (cuffs).

It is necessary to check the oil level in the support and thrust bearings, check the serviceability and prepare the bearing lubricators for operation. Check and prepare the bearing cooling system for operation.

After starting the gearbox lubrication pump, check the oil supply to the lubrication points using instruments.

It is necessary to check the operation of the disengaging couplings of the shafting, for which purpose it is necessary to make several switching on and off of the couplings from the control panel. Make sure that the operation of the on and off signaling, clutch is working properly. Leave the disengaging clutches in the off position.

In installations with controllable pitch propellers, the propeller pitch change system must be put into operation and the checks provided for in paragraph 4.8 of Part I of the Rules must be carried out.

Cranking and trial runs

When preparing a diesel engine for operation after parking, it is necessary:

crank the diesel engine with a barring device by 2-3 turns of the shaft with indicator cocks open;

crank the diesel engine forward or reverse with compressed air;

make test runs on fuel cha forward and reverse.

When turning the diesel engine with a barring device or air, the diesel engine and the gearbox must be pumped with lubricating oil, and during test runs also with cooling water.

Cranking and test runs must be carried out in installations that do not have disconnecting clutches between the diesel engine and the propeller, only with the permission of the captain on duty;

in installations operating on the propeller through a disengaging clutch, with the clutch disengaged.

Cranking and trial runs of the main diesel generators are carried out with the knowledge of the senior or watch electrician or the person responsible for the operation of electrical equipment.

Before connecting a turning device to a diesel engine, make sure that:

1. the lever (steering wheel) of the diesel control station is in the "Stop" position;

2. the valves on the starting cylinders and the starting air piping are closed;

3. at the control posts there are signs with the inscription: “The turning device is connected”;

4. indicator cocks (decompression valves) are open.

When turning the diesel engine with a barring device, it is necessary to carefully listen to the diesel engine, gearbox, hydraulic couplings. Make sure there is no water, oil or fuel in the cylinders.

During cranking, follow the readings of the ammeter for the load of the electric motor of the barring device. If the limit value of the current strength is exceeded or if it fluctuates sharply, immediately stop the barring device and eliminate the malfunction of the diesel engine or shafting. It is strictly forbidden to rotate until the malfunction is eliminated.

Turning the diesel engine with compressed air must be done with open indicator cocks (decompression valves), drain cocks of the purge air receiver and exhaust manifold. Make sure that the diesel engine accelerates normally, the turbocharger rotor rotates freely and evenly, and there are no abnormal noises when listening.

Before trial runs of the plant operating A controllable pitch screw (CPP), it is necessary to check the operation of the CPP control system. At the same time, you should make sure that the propeller pitch indicators at all control stations are consistent and the blade shifting time corresponds to that specified in the factory instructions. After checking the propeller blade, set the zero pitch position.

Trial starts of a diesel engine on fuel must be carried out with the indicator and drain valves closed. Make sure that the start and reverse systems are working, that all cylinders are working, that there are no extraneous noises and knocks, that oil is flowing to the turbocharger bearings.

In installations with remote control of main diesel engines, it is necessary to carry out test runs from all control stations (from the central control room, from the bridge), to make sure that the remote control system operates correctly.

If, due to the conditions of the vessel’s mooring, it is impossible to make trial starts of the main diesel engine on fuel, then such diesel engine is allowed to work, but at the same time a special entry must be made in the engine log, and the captain must take all necessary precautions in case it is impossible to start or reverse the diesel engine.

After the preparation of the diesel engine for start-up is completed, the pressure and temperature of water, lubricating and cooling oil, and the starting air pressure in the cylinders should be maintained within the limits recommended by the operating instructions. Shut off the sea water supply to the air coolers.

If the prepared engine is not put into operation for a long time and must be in a state of constant readiness, it is necessary every hour, in agreement with the captain on duty, to turn the engine with a turning device with open indicator valves.

Diesel engine start

Diesel start-up operations must be carried out in the sequence provided for in the operating instructions. In all cases, when it is technically possible, the diesel engine must be started without load.

When commissioning the main diesel engines in 5 - 20 minutes. before moving (depending on the type of installation) from the navigation bridge to the engine room, be an appropriate warning has been sent. During this time, the final operations must be performed to prepare the installation for operation: diesel engines are started, working on the propeller through uncoupling devices, the necessary switching in the systems is performed. The engineer on duty reports to the bridge about the readiness of the unit for starting to move in the manner adopted on the ship.

After starting, you should avoid prolonged operation of the diesel engine at idle and at the lowest load, as this leads to increased deposits of contaminants in the cylinders and flow parts of the diesel engine.

After starting the diesel engine, it is necessary to check the readings of all instrumentation, paying special attention to the pressure of lubricating oil, coolants, fuel and hydraulic mixture in the injector hydraulic locking system. Make sure there are no abnormal noises, knocks or vibrations. Check the operation of the cylinder lubricators.

If there is an automated start-up system for diesel generators, it is necessary to periodically monitor the condition of the diesel engine in the “hot standby”. In case of an unexpected automatic start of the diesel engine, it is necessary to establish the cause of the start and check the values of the controlled parameters using the available means.

It is necessary to ensure constant readiness to start the diesel drives of emergency units and rescue equipment. Checking the readiness of emergency diesel generators should be carried out in accordance with paragraphs. 13.4.4 and 13.14.1 of Part V of the Rules.

Checking the operability and readiness for starting the engines of life-saving appliances, emergency fire pumps and other emergency units must be carried out by a mechanic in charge at least once a month.

Typical malfunctions and malfunctions in the operation of diesel installations. Their prAndcauses and remedies

Malfunctions and malfunctions during start-up and maneuvers

When starting a diesel engine with compressed air, the crankshaft does not move with meWithone or, starting off, does not make a full turn.

Cause	Measures taken
1. Shut-off valves of starting cylinders or piping are closed	Open check valves
2. Starting air pressure is not enough	Refill balloons with air
3. Air (oil) is not supplied to the launch control system or its pressure is insufficient	Open valves or adjust air pressure, oil pressure
4. The crankshaft is not set to the starting position (in diesel engines with a small number of cylinders)	Set crankshaft to starting position
5. Elements of the diesel starting system are faulty (the main starting valve or the air distributor valve is stuck, the pipes from the air distributor to the starting valves are damaged, clogged, etc.)	Repair or replace system components
6. The starting system is not adjusted (the air distributor valves do not open in time, the pipes from the air distributor are incorrectly connected to the starting valves)	Adjust starting system
7. Faulty elements of the DAU system	Troubleshoot
8. Disturbed gas distribution (opening and closing angles of starting, intake and exhaust valves)	Adjust gas distribution
9. Barring air lock valve closed	Turn off the barring device or troubleshoot the block valve
10. Shaft line brake stuck	Release the brake
11. Propeller hits an obstruction or propeller	Release propeller
12. Freezing of water in the stern device	Warm up the stern tube

The diesel engine develops a rotation speed sufficient for starting, but when switching to fuel, flashes in the cylinders do not occur, or they occur with gaps, or the diesel engine stops.

Cause	Measures taken
1. Fuel is not supplied to the fuel pumps or is supplied, but in insufficient quantity	Open the shut-off valves on the fuel line, troubleshoot the fuel priming pump, clean the filters
2. Air got into the fuel system	Eliminate leaks in the system, bleed the system and injectors with fuel
3. A lot of water got into the fuel	Switch the fuel system to another service tank. Drain the system and bleed the nozzles.
4. Individual fuel pumps are off or defective	Turn on or replace fuel pumps.
5. Fuel enters the cylinders with a large delay	Set the required fuel advance angle
6. Fuel pumps disabled by speed limit controller	Put the regulator in working position
7. Stuck in the regulator mechanism or shut-off mechanism	Eliminate Jam
8. Excessively high fuel viscosity	Eliminate the malfunction in the fuel heating system, switch to diesel fuel.
9. The pressure of the end of the compression and the working cylinders is not enough	Eliminate leaky valves. Check and adjust gas distribution. Check the condition of the sealing rings.
10. Diesel not warmed up enough	Warm up diesel
11. Control valves for pumping nozzles are open or leak	Close control cocks or replace nozzles
12. Closed turbocharger filters	Open filters

During start-up, they undermine (“shoot”) safety valves

The diesel does not stop when the control lever is moved to the "Stop" position.

Cause	Measures taken
1.Zero supply fuel pumps set incorrectly	Set control levers to “Start” position for reverse (air braking). After stopping the diesel engine, set the lever to the “Stop” position On a non-reversible diesel engine, close the air inlet with improvised means, or manually turn off the fuel pumps, or close the fuel supply to the pumps. After stopping the diesel engine, adjust the zero flow of the pumps
1.1 Jamming (jamming) of rails of fuel pumps	Eliminate jamming (jamming)

The diesel engine speed is higher or lower than normal (sAgiven)

The diesel does not develop full speed with the normal position of the fuel controls.

Cause	Measures taken
1. Increased resistance to ship movement due to fouling, headwind, shallow water, etc.	Be guided by paragraphs. 2.3.2 and 2.3.3 of Part II of the Rules
2. Fuel filter dirty	Switch fuel system for a clean filter
3.Fuel is poorly atomized due to malfunctioning injectors, fuel pumps, or high fuel viscosity	Faulty injectors and fuel replace pumps. Raise fuel temperature
4. The fuel supplied to the diesel pumps is overheated	Reduce fuel temperature
5.Low purge air pressure
6. Insufficient fuel pressure in front of diesel fuel pumps	Increase fuel pressure
7. Faulty speed controller

The engine speed drops.

Cause	Measures taken
1. Piston seizing (jamming) has begun in one of the cylinders (a knock is heard with each change in the piston stroke)	Turn off the fuel immediately and increase oil supply n and the emergency cylinder, reduce the load of the diesel engine. Then stop the diesel engine and inspect the cylinder
2. Fuel contains water	Switch fuel system to receive from another service tank, drain water from the service tank tanks and systems
3. Plungers are jammed or suction valves are stuck in one or more fuel pumps	Eliminate jamming or replace the plunger pair, valve
4. The needle stuck on one of the nozzles (for diesel engines, Not having non-return valves on injectors and delivery valves on fuel pumps)	Replace nozzle. Delete WHO spirit from the fuel system

Diesel suddenly stops.

Cause	Measures taken
1. Water got into the fuel system
2. Faulty speed controller	Troubleshoot the regulator
3. The diesel emergency protection system has been triggered due to the control parameters going beyond the permissible limits or due to a system malfunction	Check the values of monitored parameters. Eliminate neis correctness of the system
4. The quick-closing valve on the service tank has closed	Open quick shutoff valve
5. No fuel tank	Switch to another service tank. Remove air from the system
6, Fuel line clogged	Clean the pipeline.

The rotational speed increases sharply, the diesel engine goes "peddling".

immediate action. Reduce the speed or stop the diesel engine using the control lever. If the diesel engine does not stop, close the air inlets of the diesel engine using improvised means, stop the fuel supply to the diesel engine.

Cause	Measures taken
1. Abrupt loss of load from the diesel engine (loss of a propeller, disengagement of the coupling, abrupt loss of load from the diesel generator, etc.) with a simultaneous malfunction of the regulator moat speed (all-mode and limit) or their drives	Check, repair and from regulate the regulator and the drive from it to the shut-off mechanism of the fuel pumps. Eliminate the cause of load shedding
2. Incorrectly set zero fuel supply, the presence of fuel or oil in the purge receiver, a large drift of oil from the crankcase into the combustion chamber of a trunk diesel engine (the diesel engine accelerates after starting at idle or removing the load)	Immediately load the diesel engine or stop air from entering the air intakes. After stopping, adjust the zero flow, inspect the diesel

Bibliography

1. Vanscheidt V.A., Design and strength calculations of marine diesel engines, L. "Shipbuilding" 1966

2. Samsonov V.I., Marine internal combustion engines, M "Transport" 1981

3. Handbook of a ship mechanic. Volume 2. Under the general editorship of Gritsai L.L.

4. Fomin Yu.Ya., Marine internal combustion engines, L .: Shipbuilding, 1989

Design, operation and maintenance. Engines with electronic control "MAN and Burmeister and Wein - ME marine diesel gas turbine engine

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The choice of fuel and oil with an analysis of the influence of their characteristics on pAbot

Applicable oils

cylinder oil must meet the following requirements:

- have the ability to neutralize acids resulting from fuel combustion and protect working surfaces from corrosion;

- prevent the deposition of deposits on pistons, cylinders and windows;

- have a high strength of the lubricating film at high pressures and temperatures;

- do not give combustion products harmful to engine parts;

- have stability during storage in ship conditions and insensitivity to water

Lubricating oils must meet the following requirements:

- to have viscosity, optimum for the given type;

- have good lubricity;

- be stable during operation and storage;

- have, if possible, a minimal tendency to soot and varnish formation;

- must not have a corrosive effect on parts;

- must not foam or evaporate.

To lubricate the cylinders of crosshead diesel engines, special cylinder oils for sour fuels with detergent and neutralizing additives are produced.

Due to the significant forcing of diesel engines by supercharging, the problem of increasing the engine life can be solved only by choosing the optimal lubrication system and the most effective oils and their additives.

Choice of fuel and oils

Elf

BP

Castrol

Chevron

Exxon

Mobile

Shell

Atlanta Marine D3005

Energol OE-HT30

Marine CDX30

Veritas 800 Marine

Exxmar XA

Alcano 308

Melina 30/305

Talusia XT70

CLO 50-M

Set control levers to

“Start” position for reverse (air braking). After stopping the diesel engine, set the lever to the “Stop” position

Switch fuel system

Faulty injectors and fuel

Turn off the fuel immediately and

Switch fuel system

to receive from another service tank, drain water from the service tank

Bibliography

1. Vanscheidt V.A., Design and strength calculations of marine diesel engines, L. "Shipbuilding" 1966

2. Samsonov V.I., Marine internal combustion engines, M "Transport" 1981

3. Handbook of a ship mechanic. Volume 2. Under the general editorship of Gritsai L.L.

4. Fomin Yu.Ya., Marine internal combustion engines, L .: Shipbuilding, 1989

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