WD10G220E21 WEICHAI Marine Diesel Engine System

WD10G220E21 WEICHAI Marine Diesel Engine System

Diesel engines are internal combustion engines that use diesel fuel as fuel. Diesel engines are compression ignition engines. They are often called Diesel engines by the name of the main inventor R. Diesel. The air sucked into the Cylinder of the diesel engine is affected by the movement of the piston. A higher degree of compression reaches a high temperature of 500-700℃. The fuel is sprayed into the high-temperature air in the form of mist and mixed with the air to form a combustible mixture (see diesel fuel injection system), which automatically ignites and burns. The energy released during combustion acts on On the top surface of the piston, the piston is pushed and converted into rotating mechanical work through the connecting rod and the crankshaft.

Working principle of diesel engine

　　1, intake stroke

　　 The starter is energized to drive the crankshaft to rotate. The rotation of the crankshaft makes the piston move from top to bottom. At this time, the exhaust valve is closed, the intake valve is opened, and fresh air enters the cylinder and combustion chamber.

　　2, compression stroke

　　 The piston moves upward from bottom dead center. At this time, both the intake valve and the exhaust valve are closed. The air sucked into the cylinder is compressed by the piston, the pressure increases, and the temperature also increases.

　　3, work schedule

When the piston is compressed to the top dead center, the injector sprays misty diesel into the combustion chamber. The oil mist and compressed air are fully mixed to form high-temperature and high-pressure gas, which starts to ignite and burn on its own. The mixed steam expands and does work, pushing the piston down. , Thereby pushing the crankshaft to rotate and outputting work externally.

　　4, exhaust stroke

The piston moves up from the bottom dead center. At this time, the intake valve is closed, the exhaust valve is opened, and the combustion exhaust gas is pushed out of the combustion chamber under the push of the piston to complete a working stroke. At this time, the crankshaft rotates for two weeks. When the diesel engine completes exhaust After the stroke, under the action of the inertia force of the crankshaft flywheel assembly, the above-mentioned working cycle process is repeated to make the diesel engine run continuously to output power

Technical characteristics of diesel engine

 1. Since the AC frequency is fixed at 50 Hz, the speed of the unit can only be 3000, 1500, 1000, 750, 500, 375 and 300r/min, mostly 1500r/min;

2. The output voltage of the diesel generator is 400/230V (large unit is 6, Deutz generator is .3kV), the frequency is 50Hz, and the power factor is 8.0cos=φ;

3. The power range is wide. The power of the diesel engine for power generation can vary from 0.5kW to tens of thousands of kW. Generally, the power of the power generation diesel engine for mobile power stations, backup power sources, emergency power sources or common rural power sources is within the range of 12~1500kW, fixed Or marine power station is used as a common power source, and its power can reach tens of thousands of kilowatts;

4. It has a certain power reserve. Diesel engines for power generation generally operate under stable conditions and have a high load rate. Emergency and backup power sources are generally calibrated to 12h power, and common power sources are calibrated to continuous power. The power of the unit should be deducted from the motor transmission loss And the excitation power, and a certain power reserve is reserved, so the matching power of the unit should be divided by the diesel engine power by the matching ratio, the matching characteristics of various diesel generator sets;

5. Equipped with a speed regulating device. In order to ensure the stability of the output voltage and frequency of the generator, a high-performance speed regulating device is generally installed, and a speed fine-tuning device is installed for the units running in parallel and integrated into the power grid;

6. With high power supply reliability and automation functions, the emergency power station with more complete functions has self-starting, automatic loading, automatic fault alarm and automatic protection functions. Shangchai generators and generator sets can run fully automatically without requiring operators. Can be unattended

Mechanism components of diesel engine

　　 The main mechanism components of a diesel engine generally include: body, crank and connecting rod mechanism, valve mechanism, fuel system, lubrication system, cooling system, and Electrical System.

1. Body: It is the skeleton of the diesel engine, which supports and installs other parts, including: cylinder block, cylinder liner, cylinder head, cylinder head gasket, oil pan, flywheel housing, timing gear housing, front and rear feet.

2. Crank and connecting rod mechanism: It is the main moving part of a diesel engine. It can convert the energy generated by fuel combustion into mechanical energy through pistons, piston Pins, connecting rods, crankshafts, and flywheels. Including crankshaft, connecting rod, piston, piston pin, piston pin circlip, piston pin bushing, piston ring, main bearing bush, connecting rod bearing, thrust bearing, front and rear crankshaft oil seal, flywheel, shock absorber, etc.

3. Air distribution mechanism: the intake and exhaust valves are opened and closed at regular intervals. Including timing gears, camshafts, tappets, jacks, rocker arms, valves, valve springs, valve seats, valve guides, valve lock blocks, intake and exhaust pipes, air filters, silencers, superchargers, etc. .

4. Fuel supply system: According to the needs of the diesel engine, the diesel fuel is supplied to the combustion chamber in a fixed and quantitative manner. Including diesel tank, fuel pipe, diesel filter, fuel injection pump, fuel injector, etc.

5. Lubrication system: It supplies lubricating oil to each movement friction pair, including oil pump, oil filter, pressure regulating valve, pipeline, instrument, oil cooler, etc.

6. Cooling system: It dissipates the heat generated by the diesel engine to the atmosphere. Including water tank, water pump, fan, water pipe, thermostat, water filter, fan belt, water temperature meter, etc.

7. Electrical appliances: auxiliary equipment for starting, lighting, monitoring, and operation. Including generators, starting motors, batteries, relays, switches, wiring, etc.