The principle of operation of a water cooler on a ship. Refrigeration machines on ships

The cooling system of a ship's power plant is designed to cool parts of the main and auxiliary engines that are heated by the heat of fuel combustion (the so-called “fire surfaces”) in order to reduce their thermal deformation and increase strength, as well as to remove heat from working media (oil, fuel , water and charge air). In addition, with the help of the cooling system, heat is removed from various other mechanisms, devices, instruments located in the machine and boiler room.

The engine cooling mode affects its operating efficiency. As the cooling water temperature increases, the indicator Engine efficiency decreases, which is explained by a decrease in the filling coefficient, the ignition delay period and the rate of pressure rise. At the same time, due to a decrease in oil viscosity, friction losses are reduced (mechanical efficiency increases) and wear of engine parts. As a result, when the water temperature changes from 50 o to 150 o C, a slight increase in the effective efficiency of the diesel engine is observed.

The temperature level of cooling affects the amount and nature of varnish and carbon formation, sedimentation and oil oxidation. With increasing temperature, oil oxidation accelerates, but varnish formation decreases. Thus, an increase in the temperature of the cooling water in the engine is accompanied by some improvement in its performance. In addition, there is a favorable redistribution of secondary energy resource flows from the point of view of heat recovery: the amount of heat removed by exhaust gases increases, and by cooling water decreases.

The cooling system consists of the following main elements: fresh and sea water pumps, filters, expansion and waste tanks and tanks for the preparation of additives, fresh cooling water, fresh and sea water heaters, inlet and outlet devices, pipelines with shut-off and control valves and control valves. measuring instruments. Coolers are designed to remove excess heat from coolants and charge air into the water. The expansion tank serves to compensate for changes in the volume of water in the system due to changes in its temperature, to replenish water losses in the system due to leaks and evaporation, as well as to remove air and water vapor from the system. Thermostats must automatically maintain the temperature of water and cooled liquids within a given range.

This project uses a three-circuit cooling system with a central fresh water cooler. This choice is due to the desire to increase the reliability of all cooled equipment, where only fresh water, which is less corrosive, is used to remove heat. Due to the fact that in the given project, the feeder container ship is equipped with a 5G50ME - B9 diesel engine, which has two cooling circuits (low-temperature and high-temperature), the fresh water circuit also consists of two parts. According to the technical documentation for diesel 5G50ME - B9 from MAN B&W for cooling the cylinder liners in order to reduce heat losses with cooling water, fresh water is used with a temperature at the entrance to the membrane space of 75 ° C and 85 ° C at the exit from it. To meet this requirement, a special high-temperature circuit is allocated in the fresh water circuit of the cooling system, which communicates with the low-temperature fresh water circuit through a control valve with a thermostat. To avoid boiling of water in the jacket space and the cooling channels of the cylinder cover, where the firing surfaces are cooled, a pressure of at least 0.25 MPa is maintained in the circuit.

Stable circulation of fresh water is achieved due to the constant removal of the steam-air mixture from the cooling cavities, ensuring complete filling of the circulation circuit with water (periodic replenishment of water) and the possibility of changing the volume of water due to the dynamics of cooling processes during operation. To do this, in each system, a drainage-compensation circuit with an expansion tank connected to the atmosphere is installed in series with the main water circulation circuit (or parallel to it). In this tank, the steam-air mixture is released from the water. It serves to replenish water leaks and is a buffer tank when the volume of water changes.

According to the Register's requirements, each engine room must have at least two kingston boxes for circulating or cooling water, ensuring the intake of sea water under any operating conditions. Currently, a kingston-distribution channel is provided, into which water flows from the kingston boxes, and then through clinker valves into the cooling system. Water is discharged overboard through non-return shut-off valves. To avoid heated water from entering the inlet openings, the ebb and flow openings are spaced along the length of the vessel, placing the latter at the bow of the ebb outlets. Drain sea openings are located on the bottom or on board, as a rule, at least 300 mm below the waterline of deepest draft.

Operating principle and composition of the main engine cooling system.

Figure 7 shows a diagram of the main engine cooling system, consisting of three circuits (two fresh water circuits with communication, and a seawater circuit). Sea water enters the cooling system through the bottom (item 2) and side (item 1) sea chests. Then the seawater, having passed through the seawater valve (item 3) and the coarse filter (dirt boxes) (item 4), enters the seawater channel (item 5), into which seawater can flow from another seawater box. Purified water is taken from the seawater channel from the seawater pump (item 6) and supplied to the central fresh water cooler (item 7), where it is heated and discharged into the drain box (item 8). In case of very low seawater temperature, part of the heated seawater after the central cooler is returned to the sea chest using a thermostat, thus maintaining the required seawater temperature at the inlet of the central cooler.

In turn, fresh water, after cooling in the central cooler, enters the inlet of the circulation pump of the low-temperature fresh water circuit (tubing) (item 10), where, having received the necessary energy, it goes to the parallel-connected main engine oil cooler (item 11) and charge air cooler ( pos. 12). Having passed through the specified heat exchangers, the heated fresh water, after merging, is divided into two streams. One flow through the throttle washer (pos. 13) passes into the averaging unit (pos. 14), where it mixes with excess fresh water from the high-temperature circuit (HTC) and returns to the central cooler, thus closing the low-temperature circuit. To regulate the temperature of the water in the low-temperature circuit, part of it, after averaging, is directed bypassing the central fresh water cooler using an automatic valve (item 15). The second flow of fresh water after merging approaches the valve of the fresh water temperature regulator of the high-temperature circuit (item 16), which doses the amount of water from the low-temperature circuit supplied to dilute the heated water of the VTK. After the thermostat (pos. 16), fresh water from the high-temperature circuit flows to the VTK circulation pumps (pos. 17). These pumps, imparting the necessary energy to the water, supply it to the main engine (item 18) to cool the cylinders. Heated water from the main engine enters the steam removal valve (item 19), installed to remove water and air vapor from the system, which are formed in small quantities on the fire surfaces of the engine and can accumulate in the system. The air and steam released in this valve are discharged into the expansion tank (item 22) through the pipeline (item 24). Having left the steam removal valve, the water, divided into two parallel flows, goes partly through the utilization desalination plant (item 20) and partly through the throttle washer (item 21), which creates the necessary pressure drop for the operation of the desalination unit. The indicated parallel flows of water, having passed the throttle washer and the desalination plant, merge and approach the valve of the fresh water temperature regulator of the high-temperature circuit, which passes the necessary part hot water for mixing with NTK water, and the excess is sent to the homogenization unit.

To compensate for the volume of water in a closed fresh water circuit when it is heated during engine operation and cooled during parking, an expansion tank (pos. 22) is installed, which, using a compensation water pipeline (pos. 23), is connected to the inlet of the VTK circulation pump, reliably thus providing it with the necessary cavitation reserve.

In addition, using a special pipeline (item 25) through the expansion tank, extra water, compensating for leaks and evaporation, and various additives are introduced. When warming up the engine before starting, a steam heater (pos. 26) is used in the cylinder cooling system.

Determination of parameters of the main equipment for completing the cooling system.

The calculation of the cooling system within the scope of this project includes the determination of the main parameters for its completion with the following equipment - fresh and sea water pumps, heat exchangers.

Fresh water pump performance.

Sea water pump performance.

Where W 4 =41,7

Based on performance from the standard size range, we select a seawater pump of the NCV 315/10A-1-11 brand with a capacity of 315 m 3 / hour

Determination of the amount of heat removed by water.

Heat removal from fresh water - ;

Heat removal with oil - ;

Heat removal from purge air - 5685 = 2840.

Calculation of fresh water cooler.

where: = 1100 kW - heat removal from fresh water;

= (25003500) W/ - heat transfer coefficient from fresh water to sea water, for a plate cooler;

We accept 3000 W/.

Temperature pressure, .

where: - the temperature difference between fresh and sea water at the end of the heat exchanger, where it is of greater importance;

Fresh water temperature at the cooler inlet;

Fresh water temperature at the outlet of the cooler,

=(30 - 35) - temperature of sea water after the cooler;

accept 35

=(40 - 45) - temperature of sea water after the cooler;

We accept 45

70 - 35 = 35

60 - 45 = 15

Oil cooler calculation

Determination of heat transfer surface area

where: - heat removal by oil;

350 W/ - heat transfer coefficient from oil to sea water, for a plate cooler;

Temperature pressure, .

where: - large temperature difference;

Less temperature difference.

Oil temperature at the cooler inlet;

Oil temperature at the cooler outlet,

35 - sea water temperature after the cooler.

55 - 30 = 25

45 - 35 = 10

Air cooler calculation

Determination of heat transfer surface area

where: - heat removal from the purge air;

=(5075) W/- heat transfer coefficient from air to sea water;

We accept 60 W/.

Temperature pressure, .

Where: - large temperature difference;

Less temperature difference.

Air temperature at the cooler inlet;

Air temperature at the cooler outlet.

30 - temperature of sea water after the cooler;

40 - sea water temperature after the cooler.

Volume of the expansion tank.

To ensure normal lubrication of engine cylinders, it is necessary that the temperature on the inner surface of their walls does not exceed 180-200°C. In this case, coking of the lubricating oil does not occur and friction losses are relatively small.

The main purpose of the cooling system is to remove heat from the liners and cylinder covers and, in some engines, from the piston heads, to cool the circulating oil and to cool the air during supercharging of diesel engines. The injector cooling system is autonomous.

Modern diesel plants have a dual-circuit cooling system consisting of closed system fresh water that cools the engines, and open system outboard, which, through heat exchangers, removes heat from fresh water, oil, charge air and directly from some elements of the installation (shaft line bearings, etc.).

Freshwater systems themselves are divided into three main cooling subsystems:

Cylinders, covers and turbochargers;

Pistons (if they are cooled with water);

Nozzles (if they are cooled with water);

The cooling system for cylinders, covers and turbochargers can have three designs:

When the vessel is moving, cooling is carried out by the main pump, and when stationary - by the parking pump; Before starting, the main engine is warmed up with water from

diesel generators;

The main engine and diesel generators have separate systems, with each diesel generator equipped with an independent pump and a cooler common to all diesel engines;

Each of the diesel engines is equipped autonomous system cooling.

The most rational is the first version of the system, where high operational reliability and survivability are ensured minimum number pumps, coolers, pipelines. In the general case, the fresh water system includes two main pumps - the main pump, the backup one (the model uses a seawater pump), one parking (port) pump, one or two coolers, thermostats (regulation by bypassing fresh water through the refrigerator), expansion tanks (compensation changes in the volume of fresh water in a closed system when the temperature changes, replenishment of the amount of water in the system), deaerators

(removal of dissolved air), pipelines, vacuum desalination plants, instrumentation.

Figure 1 shows circuit diagram dual-circuit cooling system. Circulation pump II fresh water is supplied to the water cooler 8, after which it enters the cavities of the working bushings 19 and the cover 20. Heated water from the engine is supplied through pipeline 14 to pump II and again to cooler 8. The highest located section of pipeline 14 is connected by pipe 7 to the expansion tank 5, which communicates with the atmosphere. The expansion tank ensures that the circulating engine cooling system is filled with water. At the same time, air from this system is removed through the expansion tank.

To reduce the corrosiveness of fresh water, a solution of chromium (potassium dichromate K2Cr2O7 and soda) is added to it in an amount of 2-5 g per liter of water. The solution is prepared in a mortar barrel 6, and then lowered into the expansion tank 5. To regulate the temperature of fresh water supplied to the engine, a thermostat 9 is used, which bypasses water in addition to the water cooler.

Circulation system fresh water has a backup pump 10 connected in parallel to the main pump II.

Sea water for cooling is received through the side or bottom seawall 1. From the seawater, through filters 18 that retain particles of silt, sand and dirt, it flows to the sea cooling water pump 16, which supplies it to the oil cooler 12 and water cooler 8, as well as through pipe 15 for cooling compressors, shafting bearings and other needs. But bypass pipeline 13 can allow water to pass past the oil cooler. The heated water after the water cooler 8 is discharged overboard through the outflow sea valve 4. If the temperature of the sea water is excessively low and if broken ice In the receiving seawalls, part of the heated water through pipeline 2 can be transferred into the suction line. The flow of heated water is regulated by valve 3.

The seawater cooling system has a backup pump 17 connected in parallel to the main pump 16. In some cases, one backup pump is installed for seawater and fresh water.

Sea water containing chloride, sulfate and nitrate salts is especially corrosive. Corrosivity sea ​​water 20-50 times higher than fresh water. On ships, seawater cooling system pipelines are sometimes made of non-ferrous metals. To reduce the corrosive effect of sea water, the inner surface steel pipes cover

Rice. I Cooling system diagram

zinc, bakelite and other coatings. The temperature in sea water systems should not be allowed above 50-550C, since with more high temperature salt precipitation occurs. The pressure in the sea water system created by the pumps is in the range of 0.15-0.2 MPa, and in the fresh water system 0.2-0.3 MPa.

The temperature of the sea water at the entrance to the system depends on the temperature of the water in the pool where the ship floats. The calculated temperature is 28-30°C. The temperature of fresh water at the inlet from the engine is taken to be in the range of 65-90°C, with the lower limit referring to low-speed engines, and the upper limit to high-speed engines. The temperature difference between the temperature at the outlet and inlet to the engine is taken Δt=8-100C.

To create static pressure, the expansion tank is installed above the engine. The cooling system is filled from the ship's general fresh water system.

The USSR Register rules for fresh water cooling systems allow the installation of a common expansion tank for a group of engines. The piston cooling system must be serviced by two pumps of equal capacity, one of which is a backup one. The same requirement applies to the injector cooling system.

If a vacuum desalination plant is included in the system, disinfection devices should be provided. The resulting distillate can be used for technical, sanitary and domestic needs. Evaporation installations must be made in the form of a single unit, have automation and must be operated without a special watch.

The sea cooling water system, including the second circuit of the engine cooling system, is designed to reduce the temperature of fresh water, oil and charge air of the main engine and diesel generators, auxiliary equipment machine and boiler rooms (compressors, steam condensers, evaporators, refrigeration units), propeller shaft bearings, deadwood, etc. This system can be implemented according to a scheme with a serial or parallel arrangement of heat exchangers.

The requirements of the USSR Register Rules for the sea cooling water system regarding the redundancy of units are similar to the requirements for the fresh water system.

Self-test questions

1. From what parts and assemblies is the heat of the diesel cooling system removed?

2. How are fresh cooling water systems classified?

3. What options does the cooling system have for cylinders, covers and turbochargers?

4. What units and devices are included in the fresh cooling water system?

5. The same for the sea cooling water system?

6. What functions does the expansion tank perform?

7. How is the temperature of fresh water regulated?

8. Which units in the cooling system must be backed up?

9. What are the parameters of fresh and sea water of the cooling system?

10. For what purposes is the distillate obtained in a vacuum desalination plant used?

11. What are the requirements of the USSR Register Rules for fresh and sea water systems.

12. Why is a dual-circuit circuit used to cool the engine?

Cooling system designed to remove heat from engine parts subject to heating by hot gases and to maintain permissible temperatures determined by the heat resistance of materials, thermal stability of the oil and optimal conditions progress of the work process. Depending on the design of the internal combustion engine, the amount of heat dissipated into the coolant is 15-35% of the heat released during fuel combustion in the cylinders.
Fresh and sea water, oil and diesel fuel are used as coolant.
For marine internal combustion engines, flow and closed cooling systems are used. At flow system The engine is cooled by sea water pumped by a pump. The sea water system includes the following main elements: sea chests with sea water, filters, pumps, pipelines, fittings and control, alarm and monitoring devices. According to the USSR Register Rules, the system must have one bottom and one or two side seams. The sea water system may have two pumps, one of which is a backup pump for both fresh and sea water. Emergency cooling of engines can be provided from refrigeration pumps or fire system vessel.
The flow cooling system is simple in design and requires a small number of pumps, but the engine is cooled by relatively cold sea water (no more than 50-55 C). The temperature cannot be maintained higher, since already at 45 C intensive deposition of salts begins on the cooling surface. In addition, all cavities of the system in which cooling seawater flows become heavily contaminated with sludge. Deposits of salts and sludge significantly impair heat transfer and disrupt normal engine cooling. The washed surfaces are subject to significant corrosion.
Modern marine internal combustion engines usually have closed (double-circuit) system cooling, in which fresh sea water circulates in the engine, cooled in special water coolers. Water coolers are pumped with sea water.
One of the main advantages of this system is the ability to keep the cooled cavities in a cleaner state, since the system is filled with fresh or specially purified water. This in turn makes it easy to maintain the most favorable cooling water temperature depending on the engine operating mode. The temperature of fresh water leaving the engine is maintained as follows: for low-speed internal combustion engines 65-70 C, for high-speed engines - 80-90 C. A closed cooling system is more complex than a flow one and requires increased energy consumption to operate the pumps.
To protect the surfaces of bushings and blocks on the cooling side from corrosion-cavitation destruction and scale formation, anti-corrosion emulsion oils VNIINP-117/119, Shell Dromus Oil B and others are used. These oils have almost identical physical and chemical properties and methods of application. They are non-toxic and are stored in metal containers at a temperature not lower than minus 30 C.
Anti-corrosion oils form a stable, opaque, milky emulsion with fresh water. The durability of the emulsion also depends on the hardness of the water. A thin film of anti-corrosion oil, covering the cooling surface of the internal combustion engine, protects it from corrosion, cavitation destruction and scale deposits. To maintain this film on the engine cooling surface, it is necessary to constantly maintain work concentration oil in cooling water is about 0.5% and use water of a certain quality.
Anti-corrosion emulsion oils are widely used in internal combustion engine cooling systems used on fishing vessels. Methods for treating fresh cooling water are given in the engine operating instructions.
Cooling systems use electrically driven centrifugal pumps. Sometimes there are piston pumps that are driven by the internal combustion engine itself. Cooling pumps create a pressure of 0.1-0.3 MPa. Cooling of modern medium-speed internal combustion engines is carried out mainly using mounted centrifugal pumps for sea and fresh water.
A schematic diagram of a closed engine cooling system is shown in the figure:

A closed internal circuit is used to cool the engine, and a flow external circuit is used to cool fresh water and oil refrigerators.
Water circulation in a closed circuit is carried out using centrifugal pump 8 , supplying water to the discharge pipeline 10 , from which it is supplied through separate pipes to the bottom of the engine block to cool each cylinder. From the top of the block, water flows through the overflow pipes into the cylinder covers, and from them through the outlet pipeline it is sent to the water cooler 4 and then into the pump suction line 8 . The engine cooling system has a thermostat 3 with thermal cylinder 2 , which automatically maintains the required water temperature by bypassing part of it past the water cooler 4 . The initial filling of the internal circuit with water is carried out through expansion tank 1 . The steam-air mixture from the engine exhaust pipe is also sent there.
Water supply to the external circuit is carried out autonomously centrifugal electric pump 7 , which takes water from the kingston through a paired strainer 9 With shut-off valves and supplies it sequentially to the oil 5 and water 4 refrigerators. The water from the water cooler is drained overboard. A thermostat is installed in front of the oil cooler 6 , which, depending on the oil temperature, regulates the amount of water passing through the refrigerator. The temperature and pressure of water in the cooling system is controlled by local and remote control and an emergency warning system.

The system includes:

Fresh water centrifugal pumps type KRZV-150/360 - two pieces, capacity - 30 m 3 / h, at pressure - 0.3 MPa;

Fresh water cooler type 524.15112/3253 with a cooling surface of 66.9 m2;

Heater type 521.12089/625 with a heating surface of 11.89 m2;

Pipelines, fittings, expansion tank;

Cooling water for the cylinders is supplied to the engine from the side opposite the clutch, through the main distribution manifold. Entering the cylinder block, water rises up, flowing around the cylinder liners, and enters the cylinder covers, and from there into the collection manifold located above the cylinder heads. Above it are distribution and collection manifolds for cooling the exhaust valve cages. Water is supplied and removed from each cell separately.

In order to prevent the phenomenon of corrosion in the cooling water cycle, an anti-corrosion agent is added to the fresh cooling water. We recommend Arosta M or ferroman 90 BF, 3*K-0 or Rokor NB.

The amount of fresh water in the cycle is about 8.5 m3.

Sea water cooling system

The system includes:

Seawater pump type KRZV150/360 - two pieces, capacity - 230 m 3 / h, at pressure - 0.3 MPa;

Sea water pumps type KRZIH200/315 – two pieces, with a capacity of 400 m 3 /h, at a pressure of 0.33 MPa;

Sea water cooling pumps for air compressors type WBJ32/I-200 – two pieces, capacity – 5 m 3 /h;

Kingstons, pipelines, fittings, filters;

Connected to the system:

Fresh water coolers GD;

Main engine oil coolers;

Fresh water coolers VDG;

Desalination plants;

Cooling of shafting bearings;

Boiler plant condensate cooler;

Main engine charge air coolers;

Air compressor coolers.

The cooling system is of a recuperative type, since there is a seawater tank and the temperature of the seawater can be adjusted.

Starting and control system

The main engine is started by three air cylinders for general consumption. Starting the main engine is also possible using a starting air cylinder.

One of the two air compressors is the main one, and the second is in reserve. With the help of a working air compressor all cylinders are filled compressed air. The air compressor is controlled depending on the air pressure in the cylinders automatically when the limit values ​​of the 2-position adjustment are reached. A further decrease in pressure below the limit value causes the connection of a backup air compressor. The protection circuit in the event of a lack of lubricating oil and cooling water pressure, as well as in the event of deviations from normal values ​​of the intermediate pressure in the cylinders, causes the compressors to shut down. In case of loss of power in empty air cylinders, it is possible to fill a 40 liter air cylinder with a hand compressor. This way you can start one of the VDGs.

The firing valves, mounted in the cylinder covers, are opened pneumatically by the timing valves, actuated by the camshaft timing cam, and closed by spring force.

The control station is located on the side of the diesel engine opposite the clutch. At the control station, using the flywheel, you can set the required fuel supply, along with the ability to set the supply on the speed controller.

Typical faults engine.

The main malfunctions are damage to the antifriction alloy of the upper shells of the frame bearings and coking of the turbine nozzle apparatus.

Analysis shows that during engine operation, the frame journals perform transverse vibrations in both vertical and horizontal planes. In this case, the frame bearings perceive very significant loads, which lead to the destruction of the antifriction layer.

Operational measures that improve the hydrodynamic lubrication of frame bearings are as follows: the oil clearance values ​​when installing frame and crank bearings should be set according to the minimum clearance values ​​recommended by the manufacturer's instructions. This will reduce the amplitude of transverse vibrations of the frame journals in the bearings and the dynamic loads on them. The lubricating oil pressure (LU) of the bearings should be maintained at upper value recommended by the manufacturer's instructions.

During operation of gas turbochargers (GTN) installed on 6 ChN 42/48 engines, the following damage is observed: scuffing and scratches in the blades of the compressor impeller (CM), the formation of cracks in the impeller impeller, coking of the turbine nozzle apparatus, deformation of the impeller blades and guides turbine nozzle blades.

The cause of these damages may be the contact of the blades of the turbine impeller and the guide vanes of the turbine nozzle apparatus, due to vibration of the rotor with extreme wear of its bearings.

To prevent vibration of the turbocharger parts, the rotor bearings should be replaced within the time limits recommended by the turbocharger manufacturer.

Failures of fuel equipment (FE) also occur: at fuel pumps high pressure(fuel pump) - jamming of plunger pairs, loss of density of plunger pairs and loss of density of the discharge valve; for injectors - the needle hangs in the body, reducing the spray quality.

The main reason for TA failure is corrosion of the surfaces of precision parts as a result of poor fuel preparation. Operating experience has shown that where serious attention is paid to fuel preparation, cases of TA failures are very rare, even when operating on heavy and sulfur fuels.

Thus, we can conclude that for trouble-free operation of the engine it is necessary to follow the rules technical operation(PTE) recommended by the manufacturer.

Ship power plant.

To provide electricity to consumers, two diesel generators are installed on the vessel AC, two alternating current shaft generators, one emergency diesel generator.

Characteristics of AC shaft generator:

Type DGFSO 1421- 6

Power, kW 1875

Voltage, V 390

Rotation speed, min -1 986

Type of current: alternating

Efficiency at rated load, % 96

The drive motor of the alternating current generator type DGFSO 1421-6 is the main motor. The generator rotor is driven into rotation through a gearbox using a disengaging elastic coupling. The generator is made on feet with two plain bearings mounted in shields. Bearings are lubricated from gearboxes. The slip rings and the initial excitation generator are located on the opposite side of the drive.

The generator is equipped with four electric heating elements with a total power of 600 W.

To measure temperatures remotely, six thermal resistances are installed in the generator slots. Three thermal resistances are working, the rest are spare. One similar thermal resistance is installed in the incoming and outgoing air flow. All thermal resistances are connected to the ratiometer via a switch. For remote signaling of temperature limits, the generator is equipped with two thermostats installed in the exhaust air flow. One of the thermostats is a backup. Thermostats are set to operate at a temperature of 70° C.

Signaling of the maximum temperature of the bearings is carried out using contact thermometers with a direct temperature indicator and a remote alarm contact, which is triggered at a temperature of 80 ° C. To signal the maximum temperature of the windings, two special thermostats are provided.

Characteristics of diesel generator:

Quantity 2

Rated power, kW 950

Voltage, V 390

Rotation speed, s -1 (min -1) 16.6 (1000)

Type of current: alternating

The drive motor of the S 450 LG alternator is an auxiliary motor. The generator rotor is driven into rotation through a gearbox using a disengaging elastic coupling. The generator is made on feet with two plain bearings mounted in shields. Bearings are lubricated from gearboxes. The slip rings and the initial excitation generator are located on the opposite side of the drive.

The generator is self-ventilating. Cooling air is taken from the engine room through special filters. The air exits from the generator into the ship's ventilation system through a pipe.

The generator is designed for long work with an asymmetrical load of up to 25% between any phases. The voltage asymmetry does not exceed 10% of the nominal value. A generator operating in a steady thermal nominal mode allows the following current overloads: 10% for one hour at a power factor of 0.8; 25% for 10 minutes at power factor 0.7; 50% for 5 minutes at power factor 0.6.

The self-excitation system and AVR of the 2A201 type generator is made according to the principle of current compounding using a semiconductor voltage regulator. For reliable self-excitation, an initial excitation generator is introduced into the circuit.

Elements of the self-excitation system and AVR are located on the generator in a special removable cabinet. The AVR system ensures constant voltage at the generator terminals with an error not exceeding ±2.5% at a power factor of 0.6 to 1. When applying 100% of the load to the generator or shedding a load corresponding to 50% of the rated current, with a power factor equal to 0.4%, instantaneous voltage change does not exceed 20% of the nominal value and is restored with an error of no more than ±2.5% in 1.5 s.

Protection of diesel generators from short circuit currents is carried out by maximum releases of selective circuit breakers (rated current of the circuit breaker - 750 A, maximum release - 375 A, response time - 0.38 s, response current - 750 A). The AC shaft generator is protected by an automatic circuit breaker (rated current of the circuit breaker - 1500 A, rated current of the maximum release - 125 A, response time - 0.38 s, response current - 2500 A). Minimum protection of generators is provided by minimum protection relays.

Protection of diesel generators from overloads is carried out in two stages. At 95% load of the generator, the first stage overload relay is activated accordingly with a time delay of 1 s and turns on the light and sound alarm. If the load on the diesel generator continues to increase and reaches 105%, another second stage overload relay is triggered with a time delay of 2.5 s, and an additional light alarm and at the same time, power is supplied to turn off the following consumers: heating pads, cargo devices, refrigeration unit, ventilation, RMU, fish shop, galley equipment and some other irresponsible consumers. When the load reaches 110%, the generators are disconnected from the network.

The shaft generator protection is carried out in three stages.

Feeder protection against short circuit current is provided automatic switches AZ-100 and AK-50 series.

The vessel is equipped with an electrical power plant three-phase current voltage 380 V, frequency 50 Hz. To power consumers with parameters different from those of a ship power plant, appropriate converters and transformers are provided.

For the drives of electrified mechanisms, asynchronous squirrel-cage electric motors of three-phase alternating current are installed, starting from magnetic stations or magnetic starters.

All electrical equipment installed on open decks and fish processing shops is waterproof. Electrical equipment installed in special enclosures and cabinets has a protected design. Electric motors of the AOM series are used to drive the mechanisms of the fish workshop.

The following types of lighting are provided on the vessel: main lighting, spotlights and raft lights - 220 V; emergency lighting (from batteries) – 24 V; portable lighting – 12 V; Signal lights – 24V.

Cooling of the main engine is carried out using fresh water in closed circuits. The cooling system of each engine is autonomous and is served by pumps mounted on the engines, as well as separately installed fresh water coolers and an expansion tank common to both engines.

The cooling system is equipped with thermostats that automatically maintain the set fresh water temperature by bypassing it in addition to water coolers. There is also the possibility of manually adjusting the water temperature.

Each fresh water circuit includes an oil cooler, into which water enters after the water cooler and thermostat. Filling of the expansion tank is provided from the water supply system using an open method.

The auxiliary engine is cooled using fresh water in a closed circuit. The auxiliary engine cooling system is autonomous and is serviced by a pump, water cooler and thermostat mounted on the engine.

The expansion tank with a capacity of 100 l is equipped with an indicator column, a low level indicator, and a neck.

Sea water cooling system

To receive sea water, there are two kingston boxes connected through a filter and clinket valves by a kingston line.

The cooling systems of the main and auxiliary engines are autonomous and are served by mounted seawater pumps. Mounted pumps on the main engines receive water from the seawall and pump it through the water coolers and overboard through non-return shut-off valves located below the waterline.

The auxiliary engine pump receives water from the kingston line, pumps it through the water cooler and through the non-return shut-off valve overboard below the waterline. There is also provision for water supply to the inlet pipe of the auxiliary engine pump from the pressure pipe of the sea water pump of the starboard main engine. A bypass pipe is provided to allow the auxiliary engine cooling water temperature to be controlled.

Water is drawn from the pressure pipelines of the sea water pumps of each main engine for cooling the thrust and stern tube bearings of the corresponding side.

Water is taken from the ebb lines of the main engines for recirculation into the corresponding sea chests.

The compressed air compressor is cooled with sea water from a special electric pump with water draining below the waterline overboard.

A centrifugal horizontal single-stage electric pump ESP18/1 with a supply of 1 m3 at a pressure of 10 m of water column is installed as a cooling pump for the electric compressor.

Compressed air system

The MKO is equipped with 2 compressed air cylinders with a capacity of 60 kgf/s m2.

Air from one cylinder is used to start the main engines, for the operation of the typhon and for household needs, the other cylinder is a reserve and the air from it is used only to start the main engine. The total supply of compressed air on the ship provides at least 6 starts of one main engine prepared for start-up without pumping air into the cylinders. To reduce the compressed air pressure, appropriate pressure reducing valves are installed.

Filling the cylinders with compressed air is provided from one automated electric compressor.

Compressed air cylinders with a capacity of 40 liters are equipped with heads with the necessary fittings, a pressure gauge and a blowing device.