KR20060048290A - How Turbocharger Works and Turbocharger - Google Patents

Abstract

The present invention comprises a turbine for converting the energy inherent in the first air mass, in particular the exhaust gas stream, into mechanical energy to drive the compressor 3 of the turbocharger, the second air mass in the compressor 3 of the turbocharger. It relates to a turbocharger, in particular an exhaust gas turbocharger, to which a flow 10, in particular a live air mass, can be supplied. According to the invention, an apparatus 16 for injecting a fluid 15 into the second air mass 10 is connected upstream of the compressor 3. According to the operating method of the turbocharger according to the invention, the fluid 15 is introduced into the second air mass 10 before the second air mass 10, in particular the fresh air mass, is introduced into the compressor 3 of the turbocharger. ) Is injected, and the injected fluid 15 is evaporated in the compressor 3 to cool the compressor 3.

Description

How Turbocharger Works and Turbocharger {METHOD FOR OPERATING TURBO CHARGER AND TURBO CHARGER}

1 is a schematic principle diagram of a turbocharger according to the prior art;

Figure 2 is a schematic principle diagram for explaining the operation of the turbocharger according to the present invention.

<Explanation of symbols for the main parts of the drawings>

1: exhaust gas supercharger

2: cylinder

3: compressor

4: compressor impeller

5: turbine

6: turbine impeller

7: exhaust valve

8, 9, 10, 11: arrows

12: intake valve

13: supercharged air cooler

14: supercharge pressure control device

15: fluid

16: injection device

17: pump

18: heat exchanger

The invention relates to a method of operating a turbocharger, in particular an exhaust gas turbocharger, according to the preamble of claim 1. The invention also relates to a turbocharger, in particular an exhaust gas turbocharger, according to the preamble of claim 9.

Turbochargers, in particular exhaust gas turbochargers, are used in internal combustion engines to increase power. That is, for example, DE 199 28 925 A1 has a compressor and a turbine coupled via a shaft, with which the turbine draws energy from air mass flow and converts the energy into mechanical energy, which is then mechanical energy. Discloses a turbocharger for use in driving a compressor of a turbocharger. According to the prior art, the compressor comprises a compressor impeller and a turbine impeller.

Modern turbochargers compress the air mass at a pressure high enough that the outlet of the compressor, particularly the outlet of the compressor impeller, reaches a temperature of several hundred degrees K (Kelvin) inside the compressor. It is preferable that the compressor impeller of the compressor is made of aluminum alloy. If the compressor impeller reaches a temperature of several hundred degrees K, the problem is that the aluminum alloy of the compressor impeller suffers from a constant loss of strength, especially in the outer diameter part (thermal aging). . It can lead to disabling of the compressor impeller and thus shortening the endurance life of the compressor impeller. Therefore, it is desirable to limit the temperature in the zone of the compressor impeller outlet.

It is an object of the invention starting therefrom to provide a novel turbocharger, in particular a novel exhaust gas turbocharger and a turbocharger, in particular an exhaust gas turbocharger.

Such an object is achieved by a method of operating a turbocharger according to claim 1. According to the invention, fluid is injected into the second air mass before the compressor mass flow (hereinafter also referred to as the second air mass flow), in particular the fresh air mass flow, is introduced into the compressor of the turbocharger. Evaporation in the compressor results in cooling of the compressor impeller of the compressor in particular. Such measures also affect the subsequent guiding device so that oil deposits are avoided there. In addition, the beneficial effects associated with NOx production can also be identified.

It is proposed in the sense of the present invention that a fluid is injected into the second air mass before the second air mass to be compressed by the compressor of the turbocharger is introduced into the compressor, the fluid being preferably in the compressor. Is to evaporate completely (but at least partially supported) before reaching the outlet of the compressor or compressor impeller. Thus, the decrease in strength of the compressor impeller caused by the compressor impeller exceeding the allowable temperature can be simply and surely avoided.

According to a further preferred configuration of the invention, the fluid is injected into the second air mass such that the fraction of the fluid in the entire mass flow consisting of the second air mass and the fluid is about 1%.

According to another preferred additional configuration of the invention, the fluid is compressed prior to injection of the fluid into the second air mass and at the time of injection the fluid is at a temperature between 20 K and 100 K above the boiling point of the fluid under ambient conditions of injection. Heat the fluid to have.

The turbocharger according to the invention is defined in independent claim 9.

From the dependent claims and the following detailed description, it will be apparent that the preferred improvements of the invention are apparent. Hereinafter, embodiments of the present invention, which are not limited thereto, will be described in more detail with reference to the accompanying drawings.

Hereinafter, with reference to FIG. 2, the function mode of the exhaust gas turbocharger known from the prior art will be described first, for example, of the exhaust gas turbocharger.

1 schematically shows an exhaust gas turbocharger 1 combined with a cylinder 2 of an internal combustion engine, which exhaust turbocharger 1 comprises a compressor 3 with a compressor impeller 4 and a turbine impeller And a turbine 5 provided with (6).

The first air mass, that is, the exhaust gas stream, is supplied to the turbine impeller 6 of the turbine 5 in the direction of the arrow 8 via an exhaust valve 7 assigned to the cylinder 2 of the internal combustion engine. The energy of the first air mass flow is converted into mechanical energy by the turbine impeller 6 and used to drive the compressor impeller 4 of the compressor 3 of the turbocharger 1. The first air mass stream, ie exhaust gas stream, depressurized in the zone of the turbine 5 is moved out from the turbocharger 1 in the direction of the arrow 9.

As can also be seen from FIG. 1, in the compressor 3 of the turbocharger 1, the second air mass, ie the fresh air mass, is sucked in the direction of the arrow 10 and compressed, whereby the compressed second air mass The flow can be supplied in the direction of the arrow 11 via the intake valve 12 of the internal combustion engine, ie its cylinder 2. As can be seen from FIG. 1, such an exhaust gas turbocharger also includes a boost air cooler 13 and a boost pressure control device 14.

The compressor impeller 4 of the compressor 3 of the exhaust gas turbocharger 1 shown in FIG. 1 is preferably made of aluminum alloy, with the second air mass in the compressor 3 of the exhaust gas turbocompressor 1. The flow can generate a temperature of several hundred degrees K at the outlet of the compressor impeller 4. Thereby, the allowable component temperature of the compressor impeller 4 may be exceeded, which may result in a loss of strength of the compressor impeller 4.

In the sense of the present invention (see FIG. 2), the action of injecting fluid 15 into the second air mass 10 before introducing the second air mass 10 into the compressor 3 of the turbocharger is taken. Take it. Such fluid 15 is injected into the second air mass 10 by a suitable device 16 connected upstream of the compressor 3. The fluid 15 injected into the second air mass flow 10 is evaporated in the compressor 3 to cool the compressor, ie the compressor impeller of the compressor.

In particular, the fluid 15 injected into the second air mass flow 10 is completely evaporated in the compressor. Thus, complete evaporation of the injected fluid occurs at the outlet of the compressor impeller 4. To enable it, the fluid 15 is sprayed as finely as possible when injecting the fluid 15 into the second air mass 10 by the injection device 16. It may preferably be achieved by first compressing the fluid 15 to be injected by means of a pump 17 and then by heating to a temperature defined by the heat exchanger 18. In that case, the fluid 15 is heated by the heat exchanger 18 before it is injected into the second air mass 10 so that the fluid 15 is injected at the time of injection, ie in the region of the injection device 16. It will have a temperature between 20 K and 100 K above the boiling point of the fluid 15 under ambient conditions. When a fluid 15 having such a temperature is injected into the second air mass flow 10, the fluid droplets are burned in terms of the so-called scintillation effect.

The fluid has a fraction of the fluid 15 in the total mass consisting of the fluid 15 and the second air mass 10, from 0.1% to 5%, preferably from 0.5 to 2%, more preferably about 1 It is preferable to be injected into the second air mass flow 10 so as to be%. It is preferable to inject water into the second air mass as a fluid.

As a result, in the sense of the present invention, the fluid is supplied to the second air mass before the second air mass to be compressed by the compressor of the turbocharger is supplied to the compressor, but the fluid is supplied to the outlet of the compressor impeller inside the compressor. Evaporation is taken before it is reached. Such evaporation will result in cooling of the compressor impeller or a drop in temperature. Thereby, the compressor impeller is avoided from exceeding the allowable temperature so that the loss of strength of the compressor impeller due to the temperature can be prevented.

Claims (10)

A turbocharger in which the energy inherent in the first air mass, in particular the exhaust gas stream, is converted into mechanical energy in the turbine of the turbocharger, and the compressor of the turbocharger sucks and compresses the second air mass, in particular the fresh air mass, In particular in a method of operating an exhaust gas turbocharger, Turbocharger characterized in that the fluid is injected into the second air mass before the second air mass, in particular, the fresh air mass flows into the compressor of the turbocharger, and the injected fluid is evaporated in the compressor to cool the compressor. How does it work? The method of operating a turbocharger as claimed in claim 1, wherein the fluid is sprayed when the fluid is injected into the second air mass. The method of operating a turbocharger as claimed in claim 1, wherein the fluid is compressed and heated before the fluid is injected into the second air mass. 4. The fluid according to claim 1, wherein before the fluid is injected into the second air mass, the fluid is heated such that the fluid has a temperature at 20 K to 100 K above the boiling point of the fluid at the time of injection. Operating method of turbocharger. Method according to any of the preceding claims, characterized in that the injected fluid is completely evaporated in the compressor. The method of operating a turbocharger according to any one of claims 1 to 5, wherein water is injected into the second air mass as a fluid. The fluid of any one of claims 1 to 6, wherein the fluid is injected into the second air mass such that the fraction of the fluid in the entire mass flow consisting of the second air mass and the fluid is from 0.1% to 5%. Method of operation of the turbocharger, characterized in that. 8. The method of claim 7, wherein the fraction of the fluid in the total mass of fluid consisting of the second air mass and the fluid is between 0.5% and 2%, in particular about 1%. A turbine for converting the energy inherent in the first air mass, in particular the exhaust gas stream, into mechanical energy to drive the compressor of the turbocharger, wherein the second air mass, in particular the fresh air mass, is supplied to the turbocharger compressor. In turbochargers, in particular exhaust gas turbochargers, A turbocharger, characterized in that a device for injecting fluid into a second air mass, in particular a fresh air mass, is connected upstream of the compressor. 10. The turbocharger of claim 9, wherein a heat exchanger is connected on the one hand and a compressor on the other hand upstream of the device for injecting fluid into the second air mass.

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