WO1996038666A1

WO1996038666A1 - A turbine rotor

Info

Publication number: WO1996038666A1
Application number: PCT/CZ1995/000012
Authority: WO
Inventors: Libor NOVÁK
Original assignee: Novak Libor
Priority date: 1995-06-02
Filing date: 1995-06-02
Publication date: 1996-12-05
Also published as: AU2559495A

Abstract

Turbine rotor consisting of the top face (3) and bottom face (7), hub (4), discharge ring (9) and blades (1) that are situated between both faces. Blade consists of the inlet part (2) to which the backward part (5) is connected. Discharge part (6) is then connected to the backward part (5) that revolves the water jet by 180°. Impulse and reaction blading with radial inward horizontal annular entrance, 180 + 90 degrees turn to discharge axially downwards.

Description

A turbine rotor.

Technical field

This invention relates to a turbine rotor, consisting of the top face and of the bottom face parallel with it, then of the hub and of the blades connected by a discharge ring, situated between the top face and the bottom face.

Background of the invention

Commonly used Pelton turbines can be included among the most efficient water turbines yet they posses, in spite of their considerably high efficiency, some well-known shortcomings, represented on the one hand by an unsuitable setting angle of the runner blade against the inlet water jet and on the other hand by the necessity of using a great discharge angle. A nozzle placed in the inlet, distribution section of the turbine is generally used to direct the jet of water , yet it reduces the efficiency of the turbine by 2 - 5%. Efficiency of the turbine is, understandably, also influenced by the number of working runner blades that depends on the designer's capability to utilise a limited number of nozzles. Another shortcoming of the turbines used up to now is the often ineffective elimination, possibly mini alisation of the effect of cavitation by air. Other types of water turbines in use up to now utilise standard rotors with widely different ways of gripping of the blades and the difference between the inlet and discharge angles of the water jet does not, for design reasons, amount to more than 180°. Gripping of blades and angles of inlet and discharge were applied according to the given volume and gradient of water and the type of turbine was chosen by experience accordingly. Su arv of the invention

The gist of the turbine rotor, consisting of the top face and of the bottom face parallel with it, then of the hub and of the blades connected by a discharge ring, situated between the top face and the bottom face, is based thereon, that the blade is formed by the inlet part curved from the periphery of the top face towards the centre of the hub and its bottom part is formed by the upper part of the discharge ring, to which the backward part formed by the top face, the hub and the bottom face is connected that constitutes the discharge edge from the backward part of the blades, placed in the tangent plane towards the hub and forming thus triangular prisms with rounded edges by its radial distribution and finally by the discharge part, connected to the backward part by its outer curvature, constituting connection of the tangent plane of the backward part of the blades with the tangent plane of the inner side of the bottom face, wherein the inter-blade passage is of a gradually narrowing form towards the centre of the hub. According to another embodiment of the invention, the inlet edge of the inlet part of the blade proceeds in its expanded form by its. curvature under the bottom edge of the inlet part, where it is curved under the 90° angle in order to swivel the water jet through 180° and then it is joined to the bottom edge, parallel with the inlet edge, and between them the notching is adapted, destined for the bedding of the discharge ring and forming the bottom edge of the inlet part and the upper edge of the discharge part, connected under the 90° angle to the curvature corresponding with the inner shape of the discharge ring.

Solution by the invention utilises the possibility of the activity of all blades along the whole perimeter of the rotor. To accelerate the water jet not the nozzles are used, up to now commonly placed on the turbine cylinder, but the effect of compression cones, that arise by purposeful interrelated arrangement of the blades. The substantial feature of the rotor is the zero inlet angle and 180° discharge angle in the backward, reverse part of the turbine rotor. Direction of the accelerating force corresponds to the sense of rotation and to the tangential plane. Further contribution to the increased efficiency is produced by the slight shifting of the inlet and discharge parts of the blades, especially with smaller gradients of water current. The principal advantage of the rotor by this invention consists in maintaining of the efficiency of the turbine with even reduced volumes of water. It is understandable that with the diminishing volume ratings only the output of the turbine decreases proportionately. Another principal solution lies in the recycling of cavitation flow rate.

Brief description of the drawings

The invention is further described in detail on both examples of execution according to the designs enclosed, wherein Fig. 1 shows the schematic front view of the rotor, Fig. 2 the cross-section of the Fig.l, Fig. 3 is the schematic front view of a simplified rotor and Fig. 4 the ground plan of the developed shape of the blade, used in rotor according to Fig. 1 and Fig. 2.

Detailed description of the preferred embodiments

As shown in Fig. 1 and Fig. 2 , the water turbine rotor consists of top face 3_. and bottom face 7_, and blades 1 are situated between them. Upper edge of the blade 1 bears onto the inner wall of the top face 3, at first and then proceeds by curvature from the perimeter of top face 3. towards the centre of hub 4.. This curvature is terminated at the tangential plane of the outer side of rotor blade 1 . Bottom part of the inlet part 2 forms the upper part of the discharge ring , as shown in Fig. 1. Backward part 5. is connected to the inlet part 2. This backward part 5_. is a curvature of the inlet part 2, of the hub 4 and of the bottom face 7.. Blades 1 between top face 3. and bottom face 7_ are so adjusted as to form a passage 8_. becoming narrower towards hub 4 what contributes to formation of compression cones that serve for acceleration of the water jet.

Simplified execution of the rotor as per the invention can be seen on Fig. 3. It consists of top face j3 and bottom face 7_, the adjusted blade 1. is between them. Blade 1_. is formed by the inlet part 2 shown in Fig. 1, to which the backward part 5_. is connected. Discharge part 6_, as seen in Fig. 1, is not used with rotor of this type in this case.

Fig. 4 shows the blade _L in developed shape. As can be seen on this figure, the inlet edge Q_ of the inlet part 2 of blade , drawn in detail in Fig. 1, proceeds with its curvature under the bottom edge of the inlet part 2 . Shape of the curvature can e.g. be formed by a quadratic curve i.e. for instance part of a parabola or of a hyperbola. This curvature is further curved under this edge by an angle of 90° what makes the water jet revolve by 180°. This further curvature is then connected to the bottom edge I which runs parallel with the inlet edge _LQ. Between them the notching 12. is adapted, destined for the bedding of the discharge ring £. The notching 12_. forming the bottom edge of the inlet part 2 and the upper edge of the discharge part 6_.. This discharge part 6_. is connected under the 90° angle to the curvature corresponding with the inner shape of the discharge ring £.

Industrial applicability

The turbine rotor described in the invention is suitable for fitting in all waterworks intended for transformation of energy. Further on, with appropriate adaptation and in a specific execution, it can also be used in other waterworks branches, possibly also in gas turbines.

Ve claim:

Claims

C L A I M S

1. The turbine rotor, consisting of the top face and of the bottom face parallel with it, then of the hub and of the blades connected by a discharge ring, situated between the top face and the bottom face, d e f i n e d by the blade (1) is formed by the inlet part (2) , curved from the periphery of the top face (3) towards the centre of the hub (4) and its bottom part is formed by the inlet part (2) of the discharge ring (9) , to which the backward part (5) formed by the top face, the hub (4) and the bottom face (7) is connected that constitutes the discharge edge from the backward part (5) of the blades (1) , placed in the tangent plane towards the hub (4) and forming thus triangular prisms with rounded edges by its radial distribution and finally by the discharge part (6) , connected to the backward part (5) by its outer curvature, constituting connection of the tangent plane of the backward part (5) of the blades (1) with the tangent plane of the inner side of the bottom face (7) , wherein the inter-blade (1) passage (8) is of a gradually narrowing form towards the centre of the hub (4) .

2. The turbine rotor according to claim l d e f i n e d by the inlet edge (10) of the inlet part (2) of the blade (1) proceeds in its expanded form by its curvature under the bottom edge of the inlet part (2) , where it is curved under the 90° angle in order to swivel the water jet through 180° and then it is joined to the bottom edge (11) , parallel with the inlet edge (10), and between them the notching (12) is adapted, destined for the bedding of the discharge ring (9) and forming the bottom edge of the inlet part (2) and the upper edge of the discharge part (6) , connected under the 90° angle to the curvature corresponding with the inner shape of the discharge ring (9) .