Hydrodynamic converter

Abstract

The invention relates to a hydrodynamic converter comprising a torus-shaped working chamber surrounding the converter axis, said chamber having the form of a ring channel in an axial cross-section; an impeller which is rotationally fixed to an input shaft; a turbine wheel which is rotationally fixed to an output shaft; and a ring of adjustable vanes. The converter is designed in such a way that it has a lambda value of less than 0.0005.

Description

[0001] The invention relates to a hydrodynamic converter with a torus-shaped working chamber, an impeller, a turbine wheel and a ring of adjustable guide vanes.

[0002] In particular, the invention relates to a converter for use in a machine set in which the drive is a gas turbine and the machine is a compressor. The power outputs here are extremely high, being of the order of 20 megawatts and above. Owing to these extreme power outputs, the machines also have extremely large revolving masses, which, by their very nature, lead in turn to special problems.

[0003] The requirements of a machine set of the stated type, especially one with a gas turbine and a compressor, are as follows:

[0004] the compressor must be started up without the drive being overloaded

[0005] the compressor must be run up to a speed that is equal to the speed of the drive, i.e. the two machines must run synchronously with one another

[0006] once synchronicity has been achieved, a direct mechanical drive connection must be established between the drive and the machine

[0007] in the case of many machine sets of the stated type, especially those comprising a gas turbine as a drive and a compressor as a machine, it may be necessary to have the gas turbine run continuously, even when the compressor is switched off.

[0008] In principle, a hydrodynamic converter would be suitable as an intermediate member between the gas turbine and the compressor. However, converters known hitherto are not capable of performing the functions mentioned, if only for reasons of strength. When they are partially filled, cavitation occurs owing to the high power outputs involved. When completely filled, a converter of the type stated cannot cope with the extreme power outputs required.

[0009] The object on which the invention is based is to specify a hydrodynamic converter which is suitable, in particular, as an intermediate member between a gas turbine and a compressor. A converter of this kind should be able to transmit extremely high power outputs and effect synchronicity between the gas turbine and the compressor.

[0010] The object is achieved by the features of claim 1.

[0011] The inventors have thus found a perfect solution to the problem while achieving all the component objects mentioned.

[0012] In the past, the aim with hydrodynamic converters was to achieve a high λ value in order to keep the overall volume of the converter small. Admittedly, an extremely small λ value, of the order of 0.0005, is achieved with the configuration according to the invention. At the same time, the speed ratio v between the speed of the turbine wheel and that of the impeller is of the order of one. Efficiency is high. It is of the order of 0.75 and above.

[0013] With the configuration according to the invention, the flow through the channels of the impeller is essentially centrifugal. That through the channels of the turbine wheel is essentially centripetal, something that is unusual in the case of converters. Thanks to this configuration, extremely high power outputs can be transmitted with a moderate overall volume, a high efficiency and the ability to establish the synchronized condition.

[0014] The invention is explained in detail with reference to the drawing, in which the following are illustrated in particular:

[0015] FIG. 1 shows a converter according to the invention with a tooth clutch as an intermediate member between a gas turbine (not shown) and a compressor (not shown).

[0016] FIG. 2 shows an enlarged excerpt of the subject matter of FIG. 1.

[0017] FIG. 3 shows a converter according to the invention on an enlarged scale.

[0018] FIG. 1 shows the input shaft 1 and the output shaft 2 of the converter. The converter is inserted between a gas turbine (not shown here) and a compressor (likewise not shown). The converter 3 is assigned a tooth clutch 4.

[0019] The converter 3 and the tooth clutch 4 are connected in parallel. Both the converter 3 and the tooth clutch 4 can transmit torque from the input shaft 1 to the output shaft 2 on their own but can also do so jointly.

[0020] Converter 3 can be filled and emptied. It comprises an impeller 3.1 and a turbine wheel 3.2. It furthermore comprises a fixed guide-vane wheel 3.3 and an adjustable guide-vane wheel 3.4.

[0021] The impeller 3.1 of the converter 3 is rotationally fixed to the input shaft 1. The turbine wheel 3.2 of the converter is rotationally fixed to the output shaft 2.

[0022] FIG. 2 shows the conditions in the region of the converter and the tooth clutch in greater detail. The tooth clutch 4 comprises two clutch halves. One clutch half—a pinion 4.1—is rotationally fixed to the input shaft 1. The other half—a gear ring 4.2—is rotationally fixed to the output shaft 2. Gear ring 4.2 can be displaced to the left in FIG. 2. If this displacement is performed, the clutch 4 is thereby closed.

[0023] A connection 5 for control oil is provided. Through this it is possible to introduce control oil into the interior of the clutch housing, more specifically in such a way that it acts upon a piston 4.3 which, for its part, displaces the gear ring 4.2 to the left. The connection 5 is assigned a valve (not shown here).

[0024] A set of diaphragm springs 6 is important in connection with the actuation of the clutch (see FIG. 1). While control oil displaces the piston 4.3 to the left when allowed into the connection 5 and thereby closes the clutch 4, the diaphragm springs 6 have the opposite tendency. They tend to open the clutch 4.

[0025] As described above, synchronicity between the gas turbine and the compressor is established during the start-up process, as it is therefore between the input shaft 1 and the output shaft 2. The fact that synchronicity exists is detected by sensors (not shown here). At this instant, said valve of the control-oil connection 5 is opened. Control oil enters, acts upon the piston 4.3 and displaces the gear ring 4.2 to the left, thus closing the clutch 4. The clutch remains closed until the pressure of the control oil on the piston 4.3 remains steady. The valve ahead of the connection 5 is therefore left open for as long as the clutch is to remain closed.

[0026] If the intention is to open the clutch 4, said valve of the control-oil connection 5 is closed and control oil is allowed to escape at some other point, e.g. by opening an outlet 7—see FIG. 2. If these conditions exist—control-oil inlet at connection 5 closed and control-oil outlet 7 opened—only the springs 6 act on the piston 4.3, via a rod 6.1, with the result that the piston 4.3 is moved to the right in FIG. 2, as is therefore the gear ring 4.2. The clutch is opened and torque is no longer transmitted via the clutch 4.

[0027] FIG. 3 again shows the input shaft 1, which here is simultaneously the input shaft 1 of the converter 3, and furthermore shows the driving shaft 2 of the compressor (not shown here), which here is simultaneously the output shaft 2 of the converter 3.

[0028] This figure once again shows the impeller 3.1, the turbine wheel 3.2, a fixed guide-vane wheel 3.3 and an adjustable guide-vane wheel 3.4. The arrow C indicates the direction of flow in the flow channel, which is formed essentially by the converter housing 3.5 and the blades of the impeller and the turbine wheel. As can be seen, the flow through the channels of the impeller 3.1 is centrifugal, while the flow through the channels of the turbine wheel 3.2 is centripetal.

[0029] A broken line D runs perpendicularly to the axis E of rotation of the converter. The impeller 3.1 and the turbine wheel 3.2 lie on both sides of the line D.

[0030] The figure shows the leading edge 3.1.1 and the trailing edge 3.1.2 of an impeller blade and the leading edge 3.2.2 and trailing edge 3.2.1 of a turbine blade. The leading edge 3.1.1 and the trailing edge 3.2.1 are directly opposite one another. There is thus no longer any kind of hydrodynamic element between them. These two edges are closer at the converter axis E than the two other edges 3.1.2 and 3.2.2.

[0031] If the ring channel in which the flow in accordance with arrow C flows is regarded approximately as a circular channel, it may be stated that the impeller blades are located in the first, rising quadrant and the turbine blades are located in the second, falling quadrant.

Claims

1. A hydrodynamic converter (3); 1.1 with a torus-shaped working chamber, which surrounds the converter axis (E) and has the form of a ring channel when viewed in an axial section; 1.2 with an impeller (3.1), which is rotationally fixed to an input shaft (1); 1.3 with a turbine wheel (3.2), which is rotationally fixed to an output shaft (2); 1.4 with a ring (3.4) of adjustable guide vanes; 1.5 the converter is configured in such a way that it has a lambda value of less than 0.0005.

2. The converter as claimed in claim 1, wherein the speed ratio v is of the order of one.

3. The converter as claimed in claim 1 or 2, wherein the flow through the flow channels of the impeller (3.1) is essentially centrifugal and the flow through the flow channels of the turbine, wheel (3.2) is essentially centripetal.

4. The converter as claimed in claim 3, wherein the leading edges (3.1.1) of the impeller blades and the trailing edges (3.2.1) of the turbine blades are closer to the converter axis (E) than the trailing edges (3.1.2) of the impeller blades and the leading edges (3.2.2) of the turbine blades.

5. The converter as claimed in claim 3 or 4, which comprises the following features: 5.1 the impeller (3.1) and the turbine wheel (3.2) lie on both sides of a plane (D) perpendicular to the axis; 5.2 the leading edges (3.1.1) of the impeller blades and the trailing edges (3.2.1) of the turbine blades face one another, with the result that the flow through the flow channels of the impeller (3.1) is centrifugal and the flow through the flow channels of the turbine wheel (3.2) is centripetal.

6. The converter as claimed in claim 5, wherein the impeller blades and the turbine blades are constructed and arranged symmetrically relative to the plane (D) perpendicular to the axis.

7. A machine set for high power outputs; 7.1 with a drive, which has an driven shaft; 7.2 with a machine, which has a driving shaft; 7.3 with a converter (3), which is inserted between the drive and the machine and can be filled and emptied; 7.4 with a tooth clutch (4), which is connected in parallel with the converter (3); 7.5 one clutch half (4.1) is rotationally fixed to the driven shaft of the drive; 7.6 the other clutch half (4.2) is rotationally fixed to the driving shaft of the machine; 7.7 the converter is configured in accordance with any of claims 1 to 6.