What is the working principle of diesel generator?

Working principle of diesel generator engine

The working principle of diesel engine is actually the same as that of gasoline engine. Each working cycle also goes through four strokes: intake, compression, work and exhaust. However, because the fuel used by diesel engine is diesel, its viscosity is higher than that of gasoline, it is not easy to evaporate, and its spontaneous combustion temperature is lower than that of gasoline, so the combustible mixture and ignition method are different from gasoline. A diesel engine inhales pure air when it takes in air. At the end of the compression stroke, the oil pressure of diesel oil rises from the fuel injection pump to above 10MPa, and then it is injected into the cylinder by the fuel injector, where it is mixed with compressed high-temperature air for a short time to form a combustible mixture. Due to the high compression ratio of diesel engine (generally 16-22), the in-cylinder air pressure can reach 3.5-4.5MPa and the temperature can reach 750- 1000K at the end of compression (while the mixed gas pressure of gasoline engine is 0.6- 1.2MPa and the temperature can reach 600-700K). Therefore, after diesel is injected into the cylinder, it will react with diesel in a short time. The air pressure in the cylinder rises rapidly to 6-9MPa, and the temperature also rises to 2,000-2,500 K. Driven by high-pressure gas, the piston moves downward, which drives the crankshaft to rotate and do work, and the exhaust gas is also discharged into the atmosphere through the exhaust pipe. The ordinary diesel engine is driven by the camshaft of the engine, and the diesel oil is delivered to the fuel chamber of each cylinder through the high-pressure oil pump. This fuel supply mode changes with the engine speed, so it is impossible to achieve the best fuel supply at all speeds. At present, the common rail injection system of electronically controlled diesel engine is widely used, which can solve this problem well. * * * Common rail injection fuel supply system consists of high-pressure oil pump, * * * oil pipe, injector, electronic control unit (ECU) and some pipeline pressure sensors. Each injector in the system is connected to the oil supply pipe of * * through its own high-pressure oil pipe, and the oil supply pipe and injector play the role of hydraulic energy storage. When working, the high-pressure oil pump delivers fuel to the * * * oil pipe at high pressure, and the high-pressure oil pump, pressure sensor and ECU work in a closed loop, which can accurately control the oil pressure in the * * * oil pipe and completely change the phenomenon that the oil supply pressure changes with the engine speed. Its main features are as follows: 1. Injection timing is completely separated from fuel metering, and injection pressure and injection process are controlled by ECU in real time. 2. The injection pressure, injection starting point and injection duration of each cylinder can be adjusted according to the working condition of the engine to pursue the best control point of injection. 3. High injection pressure and pre-injection of diesel oil can be realized.