What is the ignition method of a diesel engine?

[StellaFitz]

Compression ignition is an ignition method for diesel engines. Diesel engines use diesel as fuel. Compared to gasoline, diesel has a lower auto-ignition temperature (around 220°C), higher viscosity, and is less prone to evaporation. Additionally, diesel engines do not have spark plugs, and their compression ratio is higher than that of gasoline engines. Therefore, diesel engines rely on the compression stroke to compress the air-fuel mixture to the ignition point, causing it to auto-ignite. Hence, this ignition method is called compression ignition. The working principle of diesel engine ignition: The diesel engine compresses the air to generate high heat, and when atomized diesel is injected, it explodes and expands. The pressure simultaneously acts on the piston, driving it to perform non-uniform rapid linear motion along the cylinder. Through the crank-connecting rod mechanism composed of the cylinder liner, crankshaft, and rotating shaft, the linear motion of the piston is converted into the rotational motion of the gear, thereby outputting mechanical energy. The design principle of a diesel engine relies on compression ignition: The operation of a diesel engine is completed through four processes: intake, compression, combustion expansion, and exhaust. These four processes constitute one working cycle. An engine that completes one working cycle through four piston strokes is called a four-stroke diesel engine.

[WalkerRose]

Diesel engines ignite by compressing air to raise its temperature, then injecting diesel fuel for spontaneous combustion, without requiring any spark plugs. I've driven many diesel vehicles, and this design makes the engine highly efficient, with compression ratios typically above 15:1. When air is compressed to extremely high temperatures, the fuel ignites immediately upon injection. The principle is simple yet reliable, avoiding ignition issues common in gasoline engines. Diesel engines are very fuel-efficient and produce high torque, making them ideal for hauling heavy loads, though they are noticeably noisier. In cold weather, some vehicles use glow plugs to assist in warming up, ensuring smooth spontaneous combustion. Maintenance-wise, it's important to pay attention to the fuel pump and injectors to prevent clogging from impurities that could affect ignition. Overall, compression ignition is a major advantage of diesel engines, making them well-suited for long-distance driving or industrial applications.

[CorbinFitz]

Remember the invention story of diesel engine ignition? It was an innovation developed by Rudolf Diesel in the late 19th century, where compressed air raised the temperature to over 500 degrees, causing the injected fuel to ignite spontaneously. I studied this in my youth when diesel engines were still bulky, but the ignition method revolutionized efficiency by eliminating spark plug wear. Modern versions with turbocharging deliver even stronger power. Compression ignition makes diesel engines more fuel-efficient and durable, widely used in trucks and ships. The downside is slower starts in extreme cold, requiring preheating system assistance. Understanding its history made me appreciate its reliability more, unlike gasoline engines that rely on external ignition devices. I recommend testing cold-start performance when choosing a diesel vehicle.

[LaAdalynn]

I've been driving a diesel SUV for several years, and it starts purely by compressing air to raise temperature for auto-ignition. Without spark plugs, daily maintenance is simple and hassle-free. During cold starts, the preheat light flashes a few times as a reminder. It requires clean diesel fuel, as clogged injectors make ignition difficult. The vehicle delivers strong torque and shows obvious fuel efficiency on long trips. However, it's noisier and accelerates slower than gasoline vehicles. Regular replacement of air and oil filters is essential to maintain stable compression cylinder pressure. Ignition failures are mostly due to poor diesel quality or air-tightness issues. As an owner, I appreciate its rugged durability and effortless towing of camping equipment. After years of driving diesel vehicles, I've developed habits of using quality fuel and adjusting the starting mode for winter and summer.