THEREOF

Technical Field

The present invention relates to an electric turbo system which is used to reduce the delay, fuel consumption and emission in the internal combustion engine.

More specifically, the present invention relates to an electric turbo system in which compressor and turbine are located on separate shafts and, compressor is driven (operated) by a separate electric motor instead of turbine in order to eliminate all the disadvantages and limitations caused by the presence of the compressor and the turbine on the same shaft in the conventional electric turbo systems and so, in which system is made more efficient, optimal, scalable and flexible by using a separate motor and generator instead of a single machine operating as a motor-generator and, the working principle therefore.

Prior Art

In the conventional electric turbo systems, the compressor and the turbine are located on the same shaft and, the compressor is driven by turbine. Since the compressor and turbine are on the same shaft, the selection of the compressor and turbine cannot be done separately and thus, it is not possible to use the system in the most efficient way.

Since the compressor and turbine operate on the same shaft, the compressor operates at the same cycle with the turbine instead of the desired cycle. This causes the pressure of the air delivered to the internal combustion engine to be not fully controlled and the combustion efficiency to be not maintained at the maximum point. Besides, since the combustion process in the internal combustion engine cannot be performed optimally, it is not possible that the energy of the combustion gases transferred to the turbine and therefore the energy produced by the generator are at the maximum level.

The presence of the compressor and the turbine on the same shaft brings the need for bearing and consequently lubrication. The lubrication system brings extra cost, maintenance and repair workload to the turbo system although it is critically important in terms of performance and efficiency for turbos operating at very high cycle. Also, if the technical difficulties arising in the bearing and lubrication system cannot be overcome, problems will be occurred in the bearing system and they will be able to make the turbo system inoperable.

The operation of the compressor and the turbine on the same shaft causes the high temperature on the turbine side to be transmitted to the compressor side and causes the compressor to heat up. This causes that it is not completely free to choose the material for the compressor side, although not as much as on the turbine side.

The operation of the compressor and the turbine on the same shaft causes the size of the compressor, electric machine and turbine to not be selected independent to each other. The necessity of using a compressor suitable for the size of the turbine used in the system causes the air pressure transmitted to the internal combustion engine to be quite limited. While the higher-energy exhaust gases (combustion gases) can be obtained, the lower-energy exhaust gases are obtained due to smaller size compressor which has to be used because of the turbine size, consequently less energy is obtained from the generator.

Since the operation of the compressor, electric machine and turbine on the same shaft requires the system to be in the block form, it is not possible to be flexible and free concerning the placement of the system on the vehicle.

Besides, the electric machines which are used in the conventional electric turbo systems and operates bidirectional (two-way) as both motor and generator provides lower efficiency compared to the unidirectional (one-way) machines operating only as motor or generator and, this decreases the efficiency of the system.

This situation caused to occur the need for an electric turbo system that allows the compressor and the turbine to operate on the separate shafts for allowing the compressor to be independent from the turbine and that provides to increase the overall efficiency of the system by using unidirectional machines that operate only as motor and generator instead of bidirectional electric machines and, the need for working principle therefore.

The document EP2621807B1 mentions about an embodiment where plurality of compressor and of the turbine are located in parallel in separate shafts. However, there, compressors are driven by turbines since the turbine and compressor in each shaft are connected to each other, it is not mentioned about a system and working method for driving the compressor by a separate electric motor. The document DE102014208092A1 mentions about a system including a turbo and additional compressor configuration for internal combustion engines. This additional compressor is operated as a support to the turbo. The compressor in the turbo operates on the same shaft with the turbine. The turbine in the turbo is also connected to a generator and, the battery is charged with the electricity produced in the generator. Mentioned additional compressor operates with the power taken this battery. However, there is not mentioned about a system where the turbine and compressor are separated for sizing and driving the compressor separately from the turbine.

The document US2010213709A1 mentions about an embodiment where the turbine and compressor locate on the same shaft and the compressor is driven by the turbine. In addition, extra power is given to the compressor thanks to that the generator connected to the turbine operates also as motor. However, there is not mentioned about a system and method, wherein the compressor and the turbine locate on separate shafts and which includes motor and generator separately instead of two- way (bidirectional) machine working as motor-generator (electric machine)

As a result, the need for an electric turbo system in which compressor and turbine are located on separate shafts and, compressor is driven (operated) by a separate electric motor instead of turbine in order to eliminate all the disadvantages and limitations caused by the presence of the compressor and the turbine on the same shaft in the conventional electric turbo systems and so, in which system is made more efficient, optimal, scalable and flexible by using a separate motor and generator instead of a single machine operating as a motor-generator and, the working principle therefore, requires the present innovative solution to occur.

Objectives and Short Description of the Invention

Aim of the invention is to present an electric turbo system in which compressor and turbine are located on separate shafts and, compressor is driven (operated) by a separate electric motor instead of turbine in order to eliminate all the disadvantages and limitations caused by the presence of the compressor and the turbine on the same shaft in the conventional electric turbo systems and so, in which system is made more efficient, optimal, scalable and flexible by using a separate motor and generator instead of a single machine operating as a motor-generator and, the working principle therefore.

Another aim of the present invention is to enable the compressor to be controlled independent from the turbine. Another aim of the invention is to allow the compressor to operate at the desired cycles (instantaneous optimum cycles for the system or the cycles at which the compressor is most efficient) instead of the turbine cycle by controlling the compressor separately from the turbine thanks to the operation of the compressor and the turbine on the separate shafts.

Another aim of the invention is to allow the air pressure transmitted to the internal combustion engine to be maintained at the desired level by controlling the compressor speed independent from the turbine speed.

Another aim of the invention is to allow combustion within the cylinders to be occur in maximum efficiency and consequently, to maximize the energy of the exhaust gases delivered to the turbine and the amount of the electrical energy generated by the generator by keeping the air pressure delivered to the internal combustion engine at the desired level.

Another object of the invention is to enable the compressor and turbine to be used as controllable brake by creating separately controllable resistors at both the exhaust outlet and the air inlet by controlling of the speeds of the compressor and the turbine separately.

Another aim of the invention is to reduce the extra cost, maintenance and repair workload of the lubrication system and the risk of the occurrence of the technical problems by eliminating the bearing and lubrication need of the turbo system thanks to the operation of the compressor and the turbine on the separate shafts.

Another aim of the invention is to increase the response rate and efficiency of the system by using separate motor and generator instead of a two-way electric machine operating both generator and electric motor on the same shaft.

Another aim of the invention is to allow the compressor to operate at the lower temperatures compared to the conventional systems by allowing the compressor side to be less impacted from the high temperatures on the turbine side and so, to allow to be enable to operate with low-cost materials (e.g. plastic) by allowing greater freedom in the material selection for compressor, thanks to the separation of the compressor and turbine from the same shaft onto the different shafts.

Another aim of the invention is to eliminate the necessity of the system to be in block from (for making the system more flexible) by facilitating the placement of the system by separating the compressor, electric machine and turbine from each other and consequently, to minimize the losses in the gas flow system by reducing the number of twisted connections and sharp turns in this twists which increase losses in the gas flow system, thanks to the elimination of the close positioning. Another aim of the invention is to allow the size of the two components to be independently selected (flexibility in the system design) from each other thanks to the separation of the compressor and turbine from each other.

Another aim of the invention to ensure the response rate of compressor and consequently the response rate of the system to be greater than the response rate of the compressor driven by the turbine thanks to the operation of the compressor driven by bidirectional electric machine instead of the turbine and the system therefore.

Description of the Figures

In Figure 1 , the basic components of the internal combustion engine comprising the present electric turbo system is seen.

In Figure 2, the basic components and operation diagram of an internal combustion engine comprising conventional turbo are given.

In Figure 3, the basic components and operation diagram of an internal combustion engine comprising conventional electric turbo are shown.

Reference Numbers

1. Electric turbo

2. Controller

3. Compressor motor

4. Compressor

5. Intercooler

6. Suction manifold

7. Internal combustion engine

8. Exhaust manifold

9. Turbine

10. Turbine generator

11. Battery

12. Vehicle electronic control unit

13. Power converter

14. Seconder power converter

H. Air

YG. Combustion gas E. Electricity

KB. Control connection

Detailed Description of the Invention

The present invention presents an electric turbo (1) system in which compressor (4) and turbine (9) are located on separate shafts and, compressor (4) is driven (operated) by a compressor motor (3) that is a separate electric motor used instead of turbine (9) in order to eliminate all the disadvantages and limitations caused by the presence of the compressor and the turbine on the same shaft in the conventional electric turbo systems and so, in which system is made more efficient, optimal, scalable and flexible by using a separate motor and generator instead of a single machine operating as a motor-generator and, the working principle therefore.

Turbo system which allows more fuel to burn in the engine by sending (compressed) air above atmospheric pressure to the internal combustion engine and thus enables more power to be generated from the engine, is a kind of turbomachine that takes its motion energy from exhaust gas (combustion gas). A conventional turbo is basically composed of a compressor operating on the suction side and a turbine operating on the exhaust side. The compressor and turbine are connected to each other by means of a shaft and are bedded in a bearing body. The exhaust gases hit the turbine propeller and then, rotates the rotor consisting of the turbine propeller, shaft and compressor propeller. With this rotational movement, the compressor propeller increases the pressure and density of the air by sucking and compressing it. The compressed and dense air which passes to the intercooler after the compressor, cools here and becomes more intense. The condensing air is transmitted to the cylinders via the suction manifold. Since the condensing air contains more oxygen per unit volume, more fuel can be burned during the combustion process occurred in the cylinders. Burning more fuel allows the engine to generates more power by releasing more energy. Thus, it is provided that an internal combustion engine with turbo produces more power than an internal combustion engine without turbo with the same amount of fuel. The basic components and working scheme of an internal combustion engine with turbo are shown in Figure 2.

However, due to the increase in the tendency towards hybrid vehicles and in the constraints in the emission criteria in the recent years, the electric turbo concept has been introduced by changing the turbo systems. Unlike the conventional turbo system, the electric turbo system comprises an external battery and an electric machine operating with the compressor and turbine. The electric machine which operates bidirectionally both as a motor and generator, is located on the same shaft in connection with compressor and turbine. Thus, when the vehicle engine runs at low load, excess turbine energy is converted into electricity by operation of the electric machine in the turbo as a generator. The generated electricity is stored in the external battery located in the turbo system. When the engine runs at high load (when the driver loads on the vehicle pedal), the electric machine in the turbo system starts to operate as a motor and increases the rotation speed of the compressor with the power it takes (draws) from the battery. With the increase of the rotation speed of the compressor, sufficient air pressure is provided by absorbing and compressing air more quickly, thus the reaction time of the system against to the torque requirement shortens. When the turbo starts to provide sufficient air pressure alone, the electric machine stops working as a motor and then, starts to operate as a generator or becomes passive depending on the situation. Thus, as well as shortening the system reaction time, better fuel economy is provided and emissions are reduced thanks to the electric turbo system. Basic components and working scheme of an internal combustion engine with conventional electric turbo are given in Figure 3.

In the conventional electric turbo system, the compressor and the turbine are located on the same shaft and the compressor is driven by the turbine. Since the compressor and the turbine are located on the same shaft, problems occur such as; that the selection of the compressor and turbine cannot be made independently to each other, that the compressor runs at the same cycle with the turbine instead of the desired cycle, therefore the combustion process in the internal combustion engine cannot occur in maximum efficiency and the energy produced by the generator cannot be in the maximum amount, the increasement of maintenance and cost due to the requirement of the bearing and lubrication, the failure of being free for material selection in the compressor side by influencing the compressor side from the high temperature on the turbine side, that the size of the compressor cannot be selected independent from the turbine size, the increasement in the losses in gas flow system with increased number of twists and sharp turns as well as the inability to be flexible in the system design as a result of necessity in the positioning of the turbine, electric machine and compressor in the block form, that the response rate of the compressor driven by the turbine via shaft and consequently the response rate of the system are slow, and as a result it is not possible to use the system in the most efficient way.

In the present electric turbo (1) system, all the above-mentioned problems are turned into advantages thanks to the configuration of the compressor (4) and the turbine (9) on the separate shafts, the driving of the compressor (4) by means of the compressor motor (3) which is an electric motor used instead of the turbine (9) and the using a separate motor and generator instead of a single machine operating as a motor-generator.

The system components of the present invention and the interaction between them are given in Figure 1. As seen from the figure, the present electric turbo (1) system comprises a controller (2) that decides whether the electric turbo (1) system is operated,

a compressor motor (3) that is driven by being controlled by means of mentioned controller (2),

a compressor (4) which is operated with the initial energy taken from the turbine generator (10) and/or from battery (11 ) by mentioned compressor motor (3) and so, provides the suction and the pressurization of the air (H) that will be sent to the internal combustion engine (7) cylinders,

a turbine (9) in which the combustion gases (YG) formed as a result of combustion in the internal combustion engine (7) cylinders are delivered through exhaust manifold (8), a turbine generator (10) which is located on the same shaft with the turbine rotating with the energy of the combustion gases (YG) and thus, generates electricity (E) by starting to operate with the rotation of the turbine (9),

an external battery (11) in which the remaining portion of the electricity (E) (after using for operating of the compressor motor (3)) generated by mentioned turbine generator (10) is stored,

a power converter (13) which, locating between turbine generator (10) outlet and mentioned battery (11) inlet, converts the remaining portion of the electrical (E) energy (after using for operating of the compressor motor (3)) generated by the turbine generator (10) to make it suitable for storage in the battery (11),

a seconder power converter (14) which, locating between the battery (11) and compressor motor (3), coverts the energy received from the battery (11) to the suitable form for usage of the compressor motor (3).

In the present electric turbo (1) system, the compressor (4) and turbine (9) operates on the separate shafts. The energy of the exhaust gases (YG) coming from the internal combustion engine is converted to the electrical energy by the turbine generator (10) connected to the turbine (9). The compressed air (H) required in the cylinders is provided by the compressor (4) driven by a separate compressor motor (3). The electrical (E) energy required to drive the compressor motor (3) is provided by the turbine generator (10). In the case the turbine generator (10) alone cannot drive the compressor motor (3), the energy required for driving the compressor motor (3) is provided by the support of the battery (11) as well as the turbine generator (10). When the turbine generator (10) alone drives the compressor motor (3), the battery (11) is charged with the remaining energy after driving of the compressor motor (3).

In the alternative embodiments of the present invention, the number of the turbines (9) can be increased to increase the amount of the electricity (E) and consequently the charge level of the battery (11). Here, it is possible that the plurality of turbines can be used in different order for different purposes by being connected in parallel to each other while turbines may operate in series (the output of one is connected to the input of the other).

Besides, in the alternative embodiments, the plurality of compressor (4) can be used in series or parallel way for increasing the flow rate and pressure of the air (H) delivered to the cylinders.

The operating principle of the present electric turbo (1) is as follows;

Compressor motor (3) driven by being controlled by the controller (2) operates the compressor (4) with the initial drive energy received from just battery (1 1) or just turbine generator (10) or both of them depending on the situation. The compressor (4) that starts to operate, absorbs the air (H) from the external environment and increases the pressure of the air (H) that will be delivered to the cylinders. In the alternative embodiments of the invention, in which the plurality of compressor (4) can be used in series or parallel way for increasing the flow rate and pressure of the air (H) delivered to the cylinders, the controller (2) provides separate controls of all the compressors (4).

Although not mandatory, the pressurized air (H) at the compressor (4) outlet is made more intense by cooling it by passing it through the intercooler (5), if the vehicle has an intercooler (5) component. Since the condensing air (H) contains more oxygen per unit volume, the combustion process occurred in the cylinder of the internal combustion engine (7) becomes more efficient.

More dense air (H) exiting from the intercooler (5) is sent to the internal combustion engine (7) through the suction manifold (6) and is ensured to be burned in cylinders. After combustion process occurred in the cylinders, the high energy combustion gases (YG) coming to the turbine (9) through the exhaust manifold (8) rotate the turbine (9).

The rotating turbine (9) enables the turbine generator (10) connected to the same shaft with it to operate and generate electricity (E). In the alternative embodiments of the present invention with multiple series or parallel connected turbines (9) to each other in series or in parallel way in the system, the high energy combustion gas (YG) passing through the exhaust manifold (8) can be delivered to a single turbine (9) or to the plurality of turbines (9) that can be operated in different order.

The compressor motor (3) is operated by the electricity (E) generated by the turbine generator (10). After the compressor motor (3) is operated, the remaining electric (E) energy is converted by making it suitable for the battery (1 1) by means of the power converter (13) and is stored in the battery (11). Thus, after the energy stored in the battery (11) is converted to the suitable form for usage of the compressor motor (3) by means of the second power converter (14), as well as providing initial drive energy to the compressor motor (3), it is used together with the turbine generator (10) to operate the compressor motor (3) when the turbine generator (10) alone is not enough to operate the compressor motor (3).

While all these operations are carried out, the loads and temperatures in the internal combustion engine (7) are tracked by the vehicle electronic control unit (12). For maintaining the charge of the battery (11) at the highest level and adjusting the flow rate and pressure of the air (H) required in the cylinders of the internal combustion engine (7), the controller (2) controls the operation of the compressor motor (3) by tracking both the charge level of the battery (1 1) via the control connection (KB) data received from the battery (1 1) and the temperature value in the internal combustion engine (7) via the control connection (KB) data received from the vehicle electronic control unit (12).

In the conventional electric turbo systems, since the compressor is driven by the turbine, the compressor, electric machine and the turbine must be connected on the same shaft in the system. However, thanks to the present innovative electric turbo (1) system and working method, the compressor (4) is driven by the compressor motor (3) which is a separate electric motor. In the present system, the electric (E) energy required for operating the compressor motor (3) is provided by the turbine generator (10). When the turbine generator (10) alone is not enough to operate the compressor motor (3), the energy required for driving the compressor motor (3) is provided by the support of the battery (11) as well as the turbine generator (10). When the turbine generator (10) alone drives the compressor motor (3), the battery (1 1) is charged with the remaining energy after driving the compressor motor (3). Thus, the followings are becomes possible; the controlling of the compressor (4) and the turbine (9) as independent to each other (operating separately at the desired speeds), the maintaining the air (H) pressure delivered to the cylinders at the desired level, the actualizing the combustion in maximum efficiency, the maximizing the amount of the combustion gases (YG) delivered to the turbine (9) and consequently the amount of the electrical (E) energy generated in the turbine generator (10), the eliminating the bearing and lubrication need that arises due to the location of the turbine, electric machine and compressor on the same shaft, and consequently the eliminating the extra parts and maintenance costs of lubrication system, the increasement of the efficiency by using one-way equipment such as generator and motor instead of electric machine that is two-way equipment, the working with lower cost materials by being free to choose the material of the compressor (4) thanks to that the compressor (4) is prevented from being directly affected by the temperatures coming from the turbine (9), the reduction of the number of twisted connection and sharp turns which increase the losses in the gas flow system by eliminating the necessity of block shaped positioning between the turbine, electric machine and compressor, the increasing in the response rate of the system by driving the compressor (4) with the compressor motor (3) instead of the turbine (9), the independent selection of compressor (4) and turbine dimensions to each other.