Before proceeding to consider directly the turbocharger device, you should know that the power of the internal combustion engine completely depends on how much air and fuel enters it. Therefore, if you increase these indicators, it will turn out and increase the power of the internal combustion engine.
Turbine description
The device of the turbocharger and its appearance is the result of a constant race of people to increase engine power. It is important to add here that such a turbine has become an effective solution not only for gasoline engines, but also for diesel models. Most often, such devices are installed on those engines that have a small amount of incoming air. It is important to understand the following: the larger the engine itself, the more air and fuel it consumes and the more power it has. In order to achieve the same power from a smaller engine, it is necessary to increase the amount of air that fits in the cylinders.
A turbocharger is a device that is designed to pump large amounts of air into an engine using exhaust fumes. The turbocharger has two main elements - a turbine and a centrifugal pump. Between themselves, these two parts are connected by a rigid axis. Elements rotate at speeds of up to 100,000 rpm, and they also drive the compressor.
Turbine parts
The turbocharger device includes 8 parts. There is a turbine wheel that rotates in a housing with a special shape. The main purpose is to transfer exhaust energy to the compressor. The starting material for the assembly of these elements are heat-resistant materials, for example, ceramics.
The turbocharger device also includes a compressor wheel, which sucks in air. It also deals with its compression and injection into the engine cylinders. The wheel is located in a special case, like a turbine one. Both of these wheels are mounted on the rotor shaft, the rotation of which is carried out on plain bearings.
The design and operation of a turbocharger, especially in gasoline engines, requires additional cooling. This is usually a liquid cooling system. In addition to cooling the system itself, there is also cooling of compressed air. For this, the turbine has an intercooler of air or liquid type. Air cooling is necessary, as this increases its density, and hence the pressure.
This system is controlled by a pressure regulator. This bypass valve is able to restrict the flow of exhaust gases. Thus, a certain amount will pass by the turbine wheel.
Essence of the work
The device of the turbocharger and the principle of its operation is based on the use of exhaust gases. The energy of these gases will drive the turbine wheel. To transfer this energy, the turbine wheel is mounted on the rotor shaft, rotating it. In this way, energy is transmitted to the compressor wheel. This element is engaged in forcing air into the system, as well as its compression. Compressed air passes the intercooler, which cools it. After this, the substance enters directly into the engine cylinders.
additional information
The device of the turbocharger and the principle of operation are somewhat independent, on the one hand, from the internal combustion engine, since there is no rigid connection with the engine shaft. And on the other hand, the rotational speed still in some way affects the efficiency of the turbine. It is connected as follows. The more revolutions the engine makes, the more powerful the exhaust gas flow will be. Because of this, the speed of rotation of the turbine shaft will increase, which means that the amount of air that will enter the cylinders will increase.
The design and operation of the turbocharger have several negative sides. One of the disadvantages is called "turboyama". When you sharply press the gas pedal, a quick increase in power will be somewhat delayed. After the passage of the "turboyama" there is a sharp jump in pressure, which is called "turbopod".
Elimination of defects
The appearance of the first drawback is due to the fact that the system is inertial. Because of this phenomenon, a mismatch arises between the turbine capacity and the power required by the engine. In order to solve this problem, there are three ways. Since the device of a diesel turbocharger is similar to gasoline, they are suitable for it. Here's what you can do:
- Use a variable geometry turbine.
- Use two parallel or two serial compressors.
- Use a combined boost system.
As for the turbine with variable geometry, it is quite capable of solving the problem by changing the area of the inlet valve. Such a system is very often used in diesel engines.
Description of different systems
Purpose, turbocharger device are the same as for a conventional turbine. The main difference is that the device has only 5 main parts, not 8.
A system of turbines connected in parallel is used. Such a system is best suited for sufficiently powerful V-engines. In this case, one small turbocompressor is installed on each row of cylinders. The advantage is that the inertia of several small devices is less than that of a single large turbine.
The device and the principle of operation of the compressor does not differ depending on its volume, but this plays an important role, for example, when using a series connection of two turbines. In this case, each device will be switched on at certain speeds.
A boost system is also used, in which both a mechanical and a turbocharger are used. If the engine speed is low, then a mechanical device for pumping air is turned on. If you exceed a certain threshold, then the mechanical device will turn off, and the turbocharger will come into operation.
What are the benefits of a turbine?
The following advantages are highlighted when using a compressor:
- Widespread use of this device has become possible due to the simplicity and reliability of its design. In addition, the introduction of this device into the internal combustion engine system increases engine power by about 20-35%.
- The compressor itself cannot be the cause of a breakdown, since its performance directly depends on other systems, for example, gas distribution.
- It is possible to save from 5 to 20% of fuel. If you install a turbine in a small engine, the process of burning fuel will become more efficient, which means that the efficiency will increase.
- A good advantage of such engines is observed on roads passing, for example, in the mountains. This is especially noticeable when compared with atmospheric counterparts.
- The device and the principle of operation of the turbocharger allow it to perform the function of an additional silencer in the exhaust system.
Application features
Despite the fact that the compressor itself practically does not fail, occasionally there are situations when its operation stops.
Currently, the most common reason for the turbocharger to stop working is that the central cartridge of the turbine is clogged with oil. Most often, such a malfunction arises due to the fact that after prolonged and serious loads on a turbocharger, its operation stops abruptly. In order to get rid of this trouble, it is necessary to install a water cooling system. Highways of this system will create the effect of heat absorption, which will reduce the temperature in the central cartridge. It is worth noting that this effect will occur for some time after the engine stops completely, as well as after the complete cessation of coolant circulation.
Varieties of turbines
As for the types of turbocharger, there is a sleeve and ball bearing type.
If we talk about the sleeve type of a turbocharger, then they have been used for quite some time. However, they had a number of drawbacks, which was associated with their design features. This did not allow to use the potential of such a system to 100%. Ball-bearing devices are newer, in which the disadvantages were taken into account, and therefore they gradually displace sleeve compressors.
If we compare these two types of turbines, then ball-bearing is considered more economical, since it consumes significantly less oil than the sleeve type. Compressors also have an indicator that is responsible for the reaction of the turbine to pressing the gas pedal. In ball-bearing types of turbines, this indicator is better, which allows to improve the reaction by about 15%, compared with sleeve ones.
Instrument malfunctions
It is worth mentioning that the turbocharger is the only attachment equipment of the motor, which is closely connected during operation with almost all other car systems. Based on this, it becomes quite obvious that minimal deviations in the operation of any system will lead to the fact that compressor wear will increase significantly. Today, there are several reasons that most often become an obstacle in the operation of a turbine:
- Foreign objects may get into the mechanism. Due to the enormous speed of rotation of the motor, this may well lead to damage, for example, of the impellers.
- Lack of lubricants. The higher the dynamic loads, the higher the chance that the oil "film" will break. This, in turn, will lead to dry friction, which affects the system in the most negative way. The cause of this malfunction can be any reason due to which the oil does not reach fully. For example, oil cylinders, filters, oil pump wear, etc., may become clogged.