Turbocharger

1. Introduction ……………………………………………

2. Problem area ……………………………………………

3. Problem statement ………………………………………

4. Presentation of method…………………………………

5. Theory…………………………………………………..

6. Maintenance of turbocharger……………………………

7. Analysis…………………………………………………

8. Test on EGR valve, boost pressure and air mass……….

9. How to detect a turbocharge failure.……………………

10. Quality product………………………………………..

11. Conclusion……………………………………………..

1. Introduction

History

Engines are very efficient machines. Much of the energy produced from the combustion inside the engine is lost through the exhaust in the form of hot gases. In 1905 a Swiss engineer Alfred Buchi patented named first exhaust gas turbocharger using forced air to enter the engine. However, it was not until several years later when it was first adopted widely turbo plane because the altitude and air density decrease blood, reducing engine power, using both mechanical compressors solvent problem as turbochargers. It was not until the 60s, when he saw turbo application in the automotive world, but its consolidation occurred with the arrival of the first production car with turbodiesel engine, Mercedes 300D. Turbocharging diesel engines found in a symbiotic relationship. Until then diesel engines were cars, heavy, noisy and underpowered tomes. The turbo was able to improve some of these issues, which helped its expansion throughout Europe, to the point far surpass sales of gasoline engines. After the overwhelming success of diesel in Europe largely due to the turbos, we arrived at the first decade of the century, in which environmental regulations force to achieve increasingly efficient and clean cars. This leads to car manufacturers to look alternative to still meet regulatory and sell cars. The downsizing, small engines, very tight and efficient than turbo found in a perfect ally, whether gasoline or diesel. Thanks to the turbo can be given specific powers impossible to imagine until recently well in models of entry-level model with gasoline engines above 100 hp per liter. The use of turbochargers increases the amount of torque available and offers a wider range regime, so this relationship between gasoline engines and turbos is also comfortable to drive on cruises above average returns and consuming little.

2. Problem area

Turbocharger may suffer damage and various details of these can be very useful for drivers, as oil consumption which is signaled by the connections between turbocharger leaks occurred and the pipes leading to intercooler. This happens when oil comes out of the inlet seal segment of the compressor and turbine engine due to wear of rings. Failures can also occur when the air filter is clogged when the turbine is prevented and sufficient air to vacuum or if the level of the oil bath is huge, producing a flow restricting the turbocharger, and the remaining oil due to pressure refueled created in the bearing housing. The lack of pressure is also a failure, because it produces increasing fuel consumption, engine power is lost and the engine does not work consistently.

3. Problem statement

The important and the benefits of turcharger in diesel cars, how can the workshop prevent the customers for a long life of the turbocharger?

4. Presentation of method

The troubleshooting method may be the way to see how a turbocharger works. The main goal is to follow the technique and the resource we have and develop at the workshop. This method will be discus in the project, the measurement that will be used to explain the function and how the turbocharger operate. To make this project I chose to make measurements on BMW 118D 2007 with the help of Bosch ESI Tronic diagnosis device.

5. Theory

Turbocharger is driven by exhaust gas, whose main purpose is to increase iron intake air, thus, the amount that goes into the engine cylinders in the intake stroke, effectively allowing fuel to burn. The final torque and power can be raised to 35% due to turbo action. This mechanism was designed to increase the overall efficiency of the engine. Energy for driving the turbocharger is extracted from the energy wasted in the engine exhaust gas turbocharger can rotate at speeds of 120,000 rpm

Fig.1 turbocharger works

There are two types of turbo boost pressure and constant. Each operation has its own characteristics and yet so work the same basic way. After starting the engine, engine exhaust flows through the turbine wheel and shaft rotate the turbine housing brand gases are discharged into the atmosphere after passing through the turbine casing meets turbo engine load response of the engine exhaust flow growth. Due to increasing engine performance and increasing the rotational speed of the exhaust gas flow, and increases in proportion to the reference performance of the air blower motor assembly.

The advantages of Turbo

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Because the turbo is activated by exhaust gas energy, which discharge to the outside is lost, a turbocharged engine offers many advantages over conventional type. Among these we can highlight. A turbo can increase power and diesel by 35% compared to the standard version. A turbocharged four-cylinder engine can operate as a turbo V8.

Some engines are equipped with intercoolers to reduce the discharge temperature of the turbo air before entering the blower.

Fig.2 intercooler

Intercooler is a heat exchanger cooler of which is responsible for cooling the compressed air turbocharger or supercharger of an internal combustion engine. Usually the compressed gas are heated in the case of turbo gas leaves at a temperature of about 90-120 ° C. This heating is not desirable, because the less dense gas heating in which the mass per unit volume of oxygen decreases. This makes the engine volumetric efficiency and thus reduces engine power decreases because there is less oxygen for combustion.

What is intercooler?

Reduces inlet air temperature of about 60 ° C, there by gain power because the intercooler is approximately 10-15%, compared with a supercharged engine only (with intercooler).Ordinarily, they are air intercooler. Although in some cases, you can add a small stream that waters outside intercooler to cool the evaporation and increase power for a while. For engines with little training was experienced in freezing the intercooler for a short period of time to get extra power, this can be done using compressed CO2 discharge on it.

Disadvantages of turbo

Reduced power at low revolution.

When carrying little stepped on the accelerator and therefore a system of laps, the exhaust gases are considerably reduced and causes the turbo just work. The engine response time is unless a suitably low gear to increase engine speed is used.

Higher maintenance costs

Service engine turbo is more demanding than that of a standard motor and requiring a higher quality oil and changes more frequent oil, this is under harshest work having to lubricate the turbine and compressor often at very high temperatures. Turbocharged engines require better materials and lubrication systems and more efficient cooling.

Variable geometry turbochargers (VTG)

This disadvantage of conventional turbo engine have low speed turbine rotor is driven only by the exhaust gases, so that the motor behaves like air. A solution to this is to use a low blow small turbo starts compressing the intake air into the engine at low engine speeds, but this has a downside, namely that the high speed turbo fan has sufficient capacity to compress all the air motor needs, that we won power at low revs at high speed lost. To correct this problem has been sought solutions to equip the same machine blowing air capability to compress efficiently both at low and at high speed. We have developed variable geometry turbocharger.

Fig.3 turbocharger VTG

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Turbo VTG (variable geometry) turbo differs from conventionally using a plate or crown, which are mounted on a turbine blade that can be targeted to a particular mechanism rod angle and pushed the capsule using a lever similar pneumatic waste gate valve. For maximum compression at low speed air blades must be closed as lowering speeds up the exhaust section including stronger affect turbine rotor blades. Increased engine speed and increases boost pressure in the intake manifold, air capsule detected via a computer connected directly to the intake manifold tube and turn it into a motion control system for blade pressure to move to an open position that decreases speed turbine exhaust gases collide. Blades put a crown being adjustable threaded rod pneumatic capsule mandatory to open the blades before or after. If the blades are at maximum opening, this indicates a malfunction, because the maximum inclination taken to emergency function.

6. Maintenance of turbocharger

A turbo broke, without forgetting that can cause major damage to all mechanical assembly, usually involves four digits labor bills calculation workshop. Here we offer tips that will have to carefully observe whether the engine to work properly and reliably.

To start the car leaves at least one minute idling. Turbo lubrication needs, should we expect to take certain temperature, oil bathe components. This is especially important if the machine is cold. If we start walking without waiting, the system does not lubricate friction and cause damage in areas such as the turbine shaft. Long-term track eventually break and put a new turbo touch.

Start without pressing the accelerator is a habit that could be extended to any type of engine. In the case of diesel should avoid in particular presents some parts of the engine to greater efforts to account and we will be undermining long-term durability. It has heavier pieces and compression ratio is higher. Turbo can suffer much, because you have to work hard without being lubricated at all. The same can be said of other parts of the engine. To always start with the clutch down – save job starter – without acceleration.

Not sprint or apply cold engine: the logic is explained in the first paragraph. If nothing else get change from 4,000 rpm and engine load undergoes more – very good acceleration – will affect parts of the engine, which could not be lubricated at all, including the turbocharger. Cold is always advisable not to win 2,000 RPM and tread touching the accelerator? If we are to make agile leadership should not just wait until the water is optimal area of ​​oil be heated, for which we must roll at least 15 minutes.

Services even in advance manufacturers intervals do not want to sound like a maniac, but maintenance are half developed based on studies cannot access. It is supposed to be optimal, but it is always advisable to review every bit forward. The idea is to always keep the oil in good condition as it degrades with usage.

Synthetic oils have greater durability, but not sit too well in time. The mineral is exactly the opposite. In any case, it is recommended that if you have not reached revision km in a year still change oil and filters. It can be somewhat expensive, but more expensive may be a faulty internal, you cannot play with oil and useful life. If we like to give Candela car, often enter or Circuit City would do much to advance further maintenance. Do not abuse rebounds low-end or spend laps: is a concern common to all engines, but especially affects turbos. If we ask a lot from a very low engine speed RMP 1200, for example – will suffer greater load songs. Finally combustion chambers and cylinders suffered. The EGR valve turbodiesel can saturate a costly replacement be necessary. The turbines are not in your comfort zone, they cannot reach the boost pressure that makes them function properly. Let turbo engine stop before: if I was driving a long time and was quickly or city – with constant stop / start – turbo needed to rest before removing contact. In a few minutes, in all cases, it is sufficient. If you suddenly stop the oil remaining inside the charred to stop the turbine lubrication and be at a very high temperature.

VGT turbocharger benefits:

Excellent transient response

Better fuel economy

Duration proven design

Lower engine swept volume and size of the solution for a given nominal power

It helps control the exhaust gas recirculation (EGR) to meet emissions standards.

7. Analysis

7.1Masurements : MAF sensor (air flow rate by weight), which controls the air mass serves to control the mass of air entering the engine for engines running on a mixture of fuel and air to be adequate, and if the MAF that does not work, because the air mass is not appropriate and cause the engine not working well. To test the MAF sensor I use Bosch ESI Tronic device first test is when the MAF sensor work 300-350 mg/s.

Fig.4 air mass measurements

Second measurements when air mass doesn’t work because the reading of air mass is to high 582, 3 mg/s.

Fig.5 air mass measurements

8. Test on EGR valve, boost pressure and air mass

To make this test I use Bosch device in a test-drive to see how the EGR valve open on 2 different tips of RPM: low speed and full speed.

Fig. 6 EGR, air mass, boost pressure.

The EGR valve is a thinking to reduce emissions in diesel and petrol cars, normally the EGR valve is opened or closed at low and medium engine speeds.

First test is on low speed you can see how the EGR valve open on 38 %.

Second test is on full speed when maximum power demand is accelerating hard the EGR valve is closed, because in these circumstances the air supply with the largest possible amount of oxygen, fresh air is needed.

Fig. 7 EGR, air mass, boost pressure.

9. How to detect a turbocharge failure?

Insufficient lubrication

A turbo oil-free turbo is able to make not. At such high speeds, oil-free friction material instantly gate. Lack of oil can come from improper operation of motor oil pump, a hose obstruction sending engine oil or liquid use together.

Impurities in the oil

This failure can be caused by contaminated oil therefore it not changed over time, as poor quality or withdrawing the metal housing remains after a break in the engine. In short, we can find all kinds of oil solids (soot, metal chips, and liquid solidified remains of joints).

To prevent this should be reviewed; oil, oil filter, oil pan, oil hoses.

Ingestion of dust, sand or other impurities

He broke in poor condition, a clamp filter free, even a cracked hose can cause the entrance of sand, dust or salt. It may also filter replacement turbo, some small parts remain open as a washing machine. Symptoms of this type of failure is that the engine lost power and heat. If this happens, it is important to check the filter, hoses and clamps

The entry of a foreign object

Turbo can break also in the case in which foreign objects in the casing of the turbine. This defect occurs when breaking a valve or a piston, also to release the particles from the inner walls of the collector. It is important to check valves, valve seats, pistons, exhaust manifold and exhaust manifold carbonization

Very high temperature exhaust gas

The excess heat from the exhaust system causes cracking and deformation of the turbine housing. If the engine overheats, it loses power and increase consumption, it may be because the decision is from the point of injection and obstruction of catalysts and escape. To resolve this error, it is paid by injection, air filter, the intertwined or pipes

10. Quality product

The literature provides a considerable number of definitions of data quality concepts. According to some specialists, product quality is considered satisfaction of needs; the degree of consumer satisfaction; compliance with specifications; all means for achieving a viable product; a lower cost for a given use.

In practice, defining quality using a number of terms such as:

Quality of project design (quality concept) is the extent to which the product designed ensure satisfaction of beneficiaries and use the opportunity to manufacture the product concerned, technological processes of rational and economically optimal;

Quality of manufacture means the degree of conformity with the technical documentation. This is done in production and is determined by the process, production equipment, activity tracking and control, labor, etc.

Quality of delivered, representing the actual level of quality of products delivered by the supplier.

During the development of industrial production, with increasing demand and diversification of production, product quality concept has evolved and diversified talking about:

Potential quality representing product quality by design, before assimilation into production.

Partial virtues being obtained and the ratio of required quality;

Quality made the quality resulting from the checking at the end of the production line.

Quality assured quality resulting on a single program encompassing all activities of quality control (prevention, measurement and corrective action)

Total quality it integrates utility grade, economy, aesthetics, etc.

Quality is the set of properties and characteristics of a product or service that gives it the property to meet the needs expressed or implied.

For the full success of a company, it must offer products or services:

1). Satisfy a necessity, utility or a well defined

2). Satisfying customer expectations

3). Conform to standards and specifications

4). Measures to comply with legal and other requirements of society

5). Available at a competitive price

6). It is provided at a cost that brings profit

The entire profit of the factors affecting the quality of services and products (technical factors, administrative and human) should be directed to reducing, eliminating and most importantly, prevention of quality deficiencies.

To achieve maximum efficiency and to meet the expectations of buyers, it is essential that the quality management system to be appropriate type of activity and product or service.

A quality management system has two interrelated aspects, namely:

1). Needs and interests of their respective companies achieve and maintain the desired quality at optimal cost.

2). Buyer needs and expectations; there is a need for buyer confidence in the firm's ability to provide the desired quality.

Product quality is realized in the production process but in the consumer finds them. Therefore it is important to underscore the differences between product quality and product quality.

Obtaining a satisfactory quality involves the overall activities of "quality spiral", based on market research and ending with the work of analyzing, testing, sales and service.

Quality spiral represents a conceptual model of interrelated activities exercising their influence on the quality of a product or service throughout the development phases beginning with the identification of needs to assess their satisfaction.

It provides serviced turbochargers for each engine type. Workshop knows four specialized disciplines: cleaning, surface treatment, checks and balances. These four specialties make it possible for a turbocharger serviced to have the same quality or even over as a new turbocharger.

The plant parts are manufactured in series with certain margin of deviation without paid to each piece separately. This is not revision of a turbocharger happen if, during which each piece is controlled with great precision to the deviations. A revised turbocharger is therefore most rigorous than the one produced in series.

11. Conclusion

To maintain the turbocharger life is very important because are very expensive to change. Vehicles should actually be equipped with two engines. One to be able to rapidly accelerate and another to be able to maintain a constant speed. Fitting turbocharger offers a solution to this problem. Operation of a turbocharger is based on adding additional air pressure in the engine because it was to generate more power and can thus give better performance. At first technique may seem complicated but it is based on simple principles. The turbocharger offers many advantages: The weight / power in case of a turbo engine is advantageous; a turbocharger is possible to obtain a relatively significant power with a relatively small engine. A turbocharged engine features a fuel consumption advantage especially over long distances. The combustion fuel is better in the case of a turbo engine, which lowers emissions of substances novice. Turbo engine makes less noise than one atmosphere turbocharger system acts as an additional silencer. Superior performance turbo engine are better at high altitude. The turbocharger generates more energy because the counter pressure thin air at high altitudes is weaker, so that the engine generates about the same power as the lower altitudes.