A diesel engine is an internal-combustion vehicle engine. It uses compressed air and a high temperature to ignite the fuel, and this combustion then actuates a piston. This process transforms chemical energy into mechanical energy. These engines are primarily used in large tractors, freight trucks, locomotives, and marine vessels. This article will explain how a diesel engine works. Read on to find out how it works and why it is so popular.
To understand the combustion process in a diesel engine, it is helpful to visualize the variation in the cylinder pressure. A typical indicator diagram for this process can be seen in Figure 1. The vertical axis represents the cylinder pressure and the horizontal axis represents the crank angle. In a motored engine, the continuous curve represents the variation in cylinder pressure while the broken curve reflects the variation in the crank angle. In either case, the onset of fuel injection is indicated by point A, while the end of the injected fuel takes place at point B.
The fuel injected into a diesel engine is compressed and introduced into the combustion chamber. During the intake stroke, the piston drops to the bottom of its range, allowing unthrottled air to fill the cylinder. Unlike a gasoline engine, the diesel engine only draws in air, which is introduced into the cylinder as a mixture. When the piston rises, the compressed air vaporises the fuel, causing it to ignite.
The process of combustion in a diesel engine is quite complicated, but it’s easy to understand. The variations in cylinder pressure are often helpful in understanding the process. The difference between a motored and a firing engine can be represented in a typical indicator diagram. In both cases, a continuous curve shows pressure variations, while a broken curve shows changes after fuel injection. In the latter case, however, the variation doesn’t occur as quickly after the injection is initiated.
The diesel engine is a simple, efficient engine. It uses compressed air to provide power. The intake stroke is the period in which the piston drops to its bottom range. The intake stroke allows the unthrottled air to enter the cylinder. Its compression stroke begins when the piston moves upward. The compression stroke is the next phase in the process. In the gas-powered engine, the exhaust valves open during the intake stroke to introduce air and fuel into the cylinder.
The combustion process in a diesel engine can be illustrated using a typical indicator diagram. The axis in this diagram represents the cylinder pressure and the horizontal axis indicates the crank angle. A continuous curve indicates the beginning of fuel injection while a broken curve shows the starting of combustion. When the piston reaches the top dead center, the compressed air then consumes 6% of the cylinder’s area. The entire process lasts about half a second.
A diesel engine uses compressed air to generate power. The intake valves open when the piston has reached the bottom of the range. This allows the unthrottled air to enter the cylinder. It is vital to the performance of a diesel engine. When the piston is close to its top dead center, the combustion process is nearly constant-pressure. Once it moves away from this position, the intake valves close again. This process is important for the efficiency of the engine.
The basic principles of a diesel engine are similar to those of an internal-combustion engine. The difference is that a diesel engine does not use pre-mixed fuel. It uses air instead, and a piston can reach a higher pressure than a gas engine. The combustion process in a diesel engine is very efficient, and a typical diesel engine burns about one liter of fuel per hour. This type of engine also produces a lot of torque.
A diesel engine uses compressed air. The intake valves open when the piston is at the bottom of the range. The air inside the cylinder is heated to allow the fuel to ignite. During the combustion process, the fuel is vaporised into small droplets. This is the key to the combustion process in a diesel engine. Then the vaporised fuel combines with the compressed air to form the combustion product. The result is a powerful, clean diesel.