ITTO20130099A1 - TURBINE - Google Patents

Description

â € œTurbineâ €,

TEXT OF THE DESCRIPTION

Field of invention

The present invention refers to turbines in general and has been developed with particular reference to turbines for the production of hydroelectric energy. More generally, the invention relates to a machine capable of generating the rotary motion of a shaft by means of an impeller that exploits the pressure, mass and centrifugal force produced by the outgoing thrust of a fluid, in order to obtain mechanical energy available for operation. of other apparatuses.

Anterior technique

It is generally known that the mechanical power that can be obtained from the shaft of a turbine depends on various parameters, among which the flow rate and speed of the incoming fluid are of particular importance. For this reason, the construction of turbines with high power involves increasing the values of the inlet flow and / or the average speed of the inlet flow. This usually presupposes the construction of plants of significant size, with high construction, installation and management costs, as well as the availability of high fluid flow rates and speed of the flow to be fed to the turbine, with relative operating costs.

A very common type of turbine, particularly for the production of hydroelectric energy, is the Pelton turbine. The Pelton turbine, which is a classic example of an action turbine, is characterized by a remarkable simplicity of construction and maintenance, a relatively high efficiency and good operating reliability. However, Pelton turbines have the drawback of not being able to be effectively used with medium and low drop heights, for example in the order of a few meters, as their efficiency in such operating conditions would be excessively low. However, it is known that a large part of the fall heights suitable for the production of energy, and in particular hydroelectric energy, especially through small and many small production plants, are precisely the average, low and very low falls: in such situations, the exploitation of low drop heights usually involves the use of reaction turbines, such as the Francis or Kaplan turbines, which are however constructively more complicated and expensive, as well as characterized by higher maintenance costs than Pelton turbines.

Summary and purpose of the invention

In its general terms, the present invention proposes to realize a turbine, particularly a hydraulic turbine, of a relatively simple and economical structure, but of efficient operation and with high efficiency, even in the presence of relatively modest flow rates of the supply fluid and / or of medium, low and very low drop heights. The correlated purpose of the invention is that of realizing a turbine that does not require expensive maintenance and that allows to obtain higher specific powers, with the same dimensions with turbines of a known type.

One or more of the above objects are achieved, according to the present invention, by a turbine having the characteristics of claim 1. Preferential characteristics of the invention are indicated in the sub-claims.

Brief description of the drawings

Further objects, characteristics and advantages of the present invention will become clear from the following description, made with reference to the attached drawings, provided purely by way of non-limiting example, in which:

- figure 1 is a schematic representation of a possible field of application of a turbine according to the invention;

- figure 2 is a schematic side section, in partial section, of a turbine according to an embodiment of the invention;

- figure 3 is a schematic exploded view of a turbine according to an embodiment of the invention;

- figures 4, 5 and 6 are schematic views, respectively in perspective, in lateral elevation and in plan, of a flow divider of a turbine according to the invention;

- figures 7, 8 and 9 are schematic views, respectively in perspective, in lateral elevation and in plan, of a flow deflector member of a turbine according to the invention;

- Figures 10, 11 and 12 are schematic plan views of a turbine according to an embodiment of the invention, in three different operating conditions; And

- figure 13 is a partial and schematic representation of a turbine according to an embodiment of the invention, with some parts removed.

Description of preferred embodiments of the invention

The reference to "an embodiment" within this description indicates that a particular configuration, structure, or feature described in relation to the embodiment is included in at least one embodiment. Thus, the terms â € œin one embodimentâ € and the like, present in different parts within this description, are not necessarily all referring to the same embodiment. Furthermore, the particular configurations, structures or features can be combined in any suitable way in one or more embodiments. The references used here are for convenience only and do not define the scope of protection or the scope of the forms of implementation.

Figure 1 schematically represents, purely by way of example, a possible use of a turbine according to an embodiment of the present invention, indicated as a whole with 1. In the example, the turbine 1 is put into operation with the axis of rotation X of a relative impeller in a substantially vertical position, but in other possible applications - not shown here - the turbine can be installed with the X axis substantially horizontal or even differently inclined.

In figure 1, with C1 and C2 two sections of a generic channeling for conveying a water flow are indicated, between which there may also be a relatively modest difference in height, approximately between 0.5 and 3 meters. At the end of the highest section C1 the entrance Din is defined - substantially shaped like a funnel or venturi - of a duct D, which continues downwards to form a siphon Ds, and then rises up to an inlet of turbine 1. In the For example, the siphon Dssi extending at least in part below the bottom of the lowest channeling section C2. The distance in height between the lowest point of the siphon Ds and the channeling section C1 can be, for example, equal to double the difference in height between the sections C1 and C2. Still referring to the non-limiting example illustrated, turbine 1 is preferably supported above the maximum level that can be reached by the water course in the channeling section C2, by means of a support structure, not shown here, with the water in output from the turbine itself which can flow freely into section C2. Merely by way of example, in figure 1 an alternator A for the production of electricity is associated with the turbine shaft 1.

Figure 2 schematically represents, through a sectional view, a possible embodiment of a turbine 1 according to the invention. It should be noted that in this schematic figure, as well as in the following figure 3, some components have been shown in view and others in section. In general terms, the turbine 1 has a stationary structure, indicated as a whole with 10 and hereinafter defined for simplicity as `` stator '', with an inlet 11, for connection to a supply line of a fluid flow, such as for example the duct D of figure 1. The turbine 1 then comprises an impeller having a hollow mobile structure, indicated as a whole with 20 and hereinafter referred to for simplicity as â € œrotorâ €, rotatably supported by the stator 10 to rotate according to the respective axis X. As will become clear hereinafter, the rotor 20 has a plurality of flow channels extending from a peripheral part 21 of the same rotor towards a central region thereof. A front or lower part 22 of the rotor 20 has, in correspondence with its central region, an impeller inlet 23, preferably facing a terminal section of the inlet 11 of the stator 10. The inlet 23, generally coaxial to the Axis X, is in fluid communication with the inlet 11 and the aforementioned flow channels, some of which indicated with 60 and 61. Again in figure 2, with 30 a turbine shaft is indicated, operatively connected to a rear or upper part 24 of the rotor 20 (in the example of figure 1 the shaft 30 drives the alternator A).

As will become clearer hereinafter, in a preferred embodiment the rotor has a substantially disc shape, that is a generally flattened circular shape; preferably, the stator also has at least a substantially disc shape, defining a housing for the rotor 20. In more general terms, the stator 10 includes at least one of a first part (hereinafter indicated with 15) facing the front 22 of the rotor 20 and a second part (hereinafter referred to as 16) facing the rear 24 of the rotor 20, where these first and second parts are preferably substantially parallel to each other and to the front and rear of the rotor 20.

In general operation, the fluid that enters the turbine 1 from the inlet 11 penetrates inside the rotor 20 through the inlet 23, to flow into the aforementioned flow channels and then come out from the latter's outlets, particularly configured in form of inclined nozzles 70 which are located in correspondence with the peripheral part 21 of the rotor 20, thereby causing the rotation of the latter, and therefore of the shaft 30.

Referring also to Figure 3, according to a characteristic of the invention, the turbine 1 comprises, at the impeller inlet 23, a flow divider 25 configured to axially divide the flow of the fluid entering the rotor 20 into a plurality of sub-streams. According to another characteristic of the invention, the rear 24 of the rotor 20 has, in one of its central regions, a substantially conical deflector member 26, inside the cavity of the rotor 20. The deflector member 26 , which is generally facing the impeller inlet 23, extends towards the flow divider 24 and is configured to direct the axial sub-flows created by the divider itself towards the flow channels defined in the rotor 20.

The flow divider 25 is supported in a fixed position by the stationary structure 10. Preferably, moreover, the flow divider 25 extends at least partially inside the rotor 20, towards a tip of the deflector member 26. A lot preferably, the top of the flow divider 25 is at a slight distance from the tip of the deflector member 26, indicatively a distance between 0.1 and 8 mm.

A possible embodiment of the flow divider 25 can be seen in figures 4-6, from which it can be appreciated how, in a preferred embodiment, the divider itself has a generally tapered configuration in an upper region thereof.

More particularly, in the illustrated non-limiting example, the flow divider 25 includes a tubular jacket 25a, preferably cylindrical, having an upper end and a lower end, and one or more dividing walls 25b which divide an internal volume of the tubular jacket 25a into a plurality of sub-channels or sub-chambers, indicated with 25c, preferably having a substantially circular sector section.

In the illustrated example, three walls 25b are provided which extend radially from the axis of the jacket 25a, dividing its hollow volume into three axial sub-channels. Preferably, each dividing wall 25b projects axially from the jacket 25a at least at the relative upper end; more preferably, moreover, each dividing wall 25b has a generally tapered upper part, with an upper edge which extends inclined between a top of the wall itself and an upper edge of the jacket 25a. In this way the generally axial sub-flows determined by the divider 25 - schematized in F in figure 4 - can be easily deflected, in combination with the action of the diffuser element 26, in at least approximately radial directions, i.e. towards the flow channels inside the rotor 20.

In a preferred embodiment, the dividing wall 25b, or each provided dividing wall, has a generally flat upper end. This measure makes it possible to bring the top of the divider 25 closer to the tip of the organ 26, as clearly visible for example in Figure 2, without thereby compromising the precise subdivision of the incoming liquid flow. Moreover, in an embodiment not shown, the top of the divider, even if of pointed configuration, can find a correspondence in a suitable cavity or housing made in the tip area of the body of the deflector member 26, so as to allow free rotation of the second with respect to the first.

A flange formation 25c is preferably provided at the base of the jacket 25a, provided with through holes for screws used for fixing the divider 25 at the inlet 11 of the stator.

In figures 7-9, on the other hand, the deflector organ 26 is visible, here defined for simplicity as â € œsubstantially conicalâ €: preferably, in reality, the organ 26 substantially has a 360 ° exponential conical profile, that is substantially bell-shaped or with curved profile; in other words - and as can be appreciated in figures 7 and 8 - the profile of the organ 26, when seen in lateral elevation, resembles a gauss curve. The organ 26 is located inside the cavity of the rotor 20 and is integral, at its base 26a, with the rear 24 of the rotor, so as to be directly facing the divider 25. As previously explained, with this arrangement, the sub-flows F determined by the divider 25 can be effectively directed into the flow channels of the rotor 20. In the exemplified embodiment, holes with nut screw 26b are defined at the base 26a of the organ 26b, for its fixing with threaded members at the rear 24 of the rotor; in the example, in correspondence with the base 25a there is also preferably but not necessarily provided a central seat 26c, for housing the lower end of the turbine shaft 30.

The divider 25, together with the deflector 26, allows to eliminate any vortices produced by the rotation of the impeller, in order to obtain a homogeneous flow of the water flow directed against the diffuser element 26 and orient it in the flow channels where the force develops centrifuge. As will be seen below, inside the hollow volume of the impeller 20 the water is directed into the flow channels 60, 61 preferably arranged substantially in a radial pattern, which convey the water itself towards the respective inclined nozzles 70.

Referring again to Figure 2, in a preferred embodiment the turbine 1 comprising a plurality of contrast elements, two of which indicated with 40, which are preferably arranged according to a circumference (see also Figure 13 for reference) and are supported by the stator 10, in a position generally facing the peripheral part 21 of the rotor 20, in which the nozzles 70 are located. The presence of the contrasting elements 40 is preferable, as it allows to increase the turbine efficiency, but is not an essential characteristic of the turbine. ™ invention.

In a preferred embodiment, the turbine 1 has at least one actuation system for varying the position of the contrast elements 40 in a controlled manner. For this purpose, the contrast elements 40 are preferably mounted on the stator 10 in a mobile way, to vary the position of one of their contrast surfaces with respect to the jets of the fluid leaving the terminal nozzles 70 from the flow channels of the rotor 20. Two of these jets are exemplified in figure 13, where they are indicated by J. Preferably, the elements 40 are mounted on the stator 10 to be angularly movable according to respective axes generally parallel to the rotation axis X of the rotor 20.

In general, in at least one of the positions that can be assumed by the contrasting elements 40, the relative contrasting surface is susceptible to being hit by the jets leaving the rotor 20 with a first angle of incidence; in at least one other position of the elements 40, the relative surface is hit by the jets leaving the rotor 20 with a different angle of incidence. As will be seen below, the presence of the contrast elements 40, and the possibility of varying their position, allows the centrifugal thrust of the rotor 20 to be kept constant in the event of pressure variations in the inlet flow, particularly in the event of lowering of pressure (being the maximum pressure at the inlet to the turbines generally regulated upstream).

In figure 3 the structure of the turbine 1, in one of its preferential embodiments, is illustrated by means of an exploded schematic view.

D1 indicates a connecting flange of the fluid supply duct D, intended for coupling with a flange part 12a of a lower tubular support 12, defining the inlet 11 of the turbine 1, formed for example with metal material .

The lower support 12 has an upper ring nut portion 12b, in correspondence with which the flow divider 25, also preferably of metal material, is fixed, for example by means of threaded members, in an axial position at the inlet 11. An upper metal tubular support 13 is associated with the lower support 12, and in particular on the outside of its ring nut part 12b, within which sealing means are operative. In a preferred embodiment, the aforementioned sealing means include one or more gaskets 14a supported by a gasket holder ring 14. Preferably, at least one of each gasket 14a and the gasket holder ring 14 is formed at least in part with a high strength material, such as a synthetic material based on PTFE or ECTFE; for example, a material that can be used with advantage for this purpose is the one known by the trade name Turcite®. As will become clear below, a tubular part (23a) of the rotor 20, which defines the impeller inlet 23, is inserted into the tubular part represented by the upper fitting 12, with the aforementioned sealing means 14-14a interposed.

In one embodiment, the stator 10 has at least one portion with a substantially disc shape, that is, of a generally flattened circular shape, defining a cavity or housing for the rotor 20, this housing being indicated with C in Figure 2. In the example not limitation of figure 3, the upper support 13 is fixed to a lower bearing structure 15 of the stator 10, for example comprising a metal plate, preferably discoidal, with a central opening 15a in correspondence with which the support 13 is fixed. A peripheral wall 15b is integral with the upper face of the structure 15, preferably constituted by a metal ring, for example fixed in position by welding or by means of threaded members.

The reference number 16 indicates an upper bearing structure of the stator 10, preferably of construction similar to the lower structure 15. Also the structure 16 can therefore include a metal plate, preferably discoidal, with a central opening 16a, whose lower face is integral with a peripheral wall 16b, preferably consisting of a metal ring with a diameter substantially corresponding to that of the homologous wall 15b of the lower structure 15. Preferably, at least one of the two structures 15 and 16 has an external diameter greater than the external diameter of the rotor 10, so as to have a respective peripheral region which protrudes in a radial direction beyond the peripheral part 21 of the rotor (see for example Figure 2): advantageously, the previously mentioned contrasting elements 40 can be associated with such a peripheral region. In the example shown, the walls 15b, 16b have a smaller diameter than that of the plates which make up the structures 15 and 16, so that the latter each have an aforementioned peripheral region, here annular, with the contrast elements 40 which are associated to the upper structure 16.

The presence of walls 15b and 16b, although preferable, is not strictly necessary for the implementation of the invention. In general terms, the parts 15-16 of the stator 10 which define the housing C of the rotor 20 can form a peripheral part (here represented by the walls 15b and 16b), which faces the peripheral part 21 of the rotor 20 and substantially coaxial to it: this peripheral part of the stator, if present, preferably defines a circumferential opening, in order to allow the jets of fluid to escape. For this purpose, in the example shown, the lower 15 and upper 16 structures are made integral with each other with the tops of the respective peripheral walls 15b, 16b substantially facing at a certain distance, so as to define the aforementioned circumferential opening between them.

The fastening between the two structures 15, 16 can be achieved by means of fastening members outside the housing C, in any case in positions that do not interfere with the rotation of the rotor 10. In an embodiment, such as the one illustrated, for this purpose threaded members are provided, arranged in correspondence with the aforementioned peripheral region of the structures 15 and 16. Referring to Figures 2 and 3, these fastening members include spacer elements 17, for example metal, provided with blind holes with nut screws at the two axial ends ; threaded pins 17a are screwed into these blind holes, passing through relative holes 15c and 16c provided in the peripheral part of the structures 15 and 16; fixing is completed by tightening nuts 17b at the external ends of the aforesaid pins 17a.

As already mentioned, in a preferred embodiment, the rotor 20 also has a substantially disc shape, that is, a generally flattened circular shape, with the relative front 22, rear 24 and peripheral part 21 (figure 2) which delimit a hollow volume, preferably substantially cylindrical.

In the example shown, the structure of the rotor 20 includes a tubular part, represented here by an inlet sleeve 23a, which defines the impeller inlet 23 and which is generally coaxial to the inlet 11 of the stator 10 and to the € ™ X axis of rotation of the rotor. Preferably, the sleeve 23a has an inlet end with a diameter substantially corresponding to the terminal diameter of the inlet 11 and an outlet end which has a generally flared profile towards the inside of the rotor, in order to facilitate the inlet fluid flow. The rotor sleeve 23a is intended to be inserted into the upper support 13, with the interposition of the sealing means represented by the gasket-holder ring 14 with the relative gaskets 14a.

Referring again to Figure 3, in the example the sleeve 23a is coupled to the central opening 22a1 of a lower plate 22a of the rotor 20, preferably metallic and generally disc-shaped, which belongs to the front of the rotor. The structure then includes an upper plate 24a, which belongs to the rear of the rotor, also preferably metallic and disc-shaped, with a diameter substantially equal to that of the lower plate 22a. A ring 21a is fixed between the two plates 22a, 24a, also preferably metallic, which forms the peripheral part 21 of the rotor. As explained below, in the preferred embodiment of the invention, the hollow volume inside the rotor is divided into the flow channels, whose outlets - including the nozzles 70 - are in correspondence with its peripheral part 21, here including the ring 21a.

On the inner side of the upper plate 24a, and therefore inside the hollow volume of the rotor 20, the deflector member 26 described above is fixed in a central position, in a position axially aligned with the impeller inlet 23 and with the divider of flow 25. The shaft 30 of the turbine 1 is made integral with the opposite side of the upper plate 24a, preferably but not necessarily in correspondence with a central opening 24a1 of the plate 24a, for example in combination with a relative fixing flange 30a.

Bearing means or similar guiding devices are preferably coupled to the shaft 30, suitable for reducing the friction between parts in rotary motion, such as an assembly including two bearings 31a with a spacer 31b interposed, this assembly being packed on the ™ shaft 30 by means of a ring nut 31c. The shaft 30, with the associated bearing means, passes through the central opening 16a of the upper structure 16, to which a support 32 is made integral for housing the bearings, of any known concept, from which protrudes from above an end portion of the shaft 30. The fixing of the support 32 to the upper structure can be achieved by means of threaded members, some of which are indicated with 33. Preferably, the support 32 has a circular base flange 32a, intended resting on the upper structure 16 of the stator 10.

In the example shown, and as can also be seen in Figure 2, the contrast elements 40 are mounted in correspondence with the peripheral region of the upper structure (but it could also be the lower one), each of which includes a respective body carried by a relative shaft 42 associated with the upper structure 16, here configured as a threaded pin with associated locking nuts. The body of the contrast elements 40 can comprise for example longitudinally extended blades or fins, as exemplified in Figure 13, preferably with an at least slightly curved distal end.

As already mentioned, in one embodiment, the turbine 1 comprises at least one actuation system for varying the position of the contrast elements 40 in a controlled manner. This actuation system preferably comprises:

- a rotatable element, particularly an annular plate, constrained on the stator 10 to be angularly movable around the axis of rotation X of the rotor 10;

- transmission means, particularly a system of arms and pins, for connecting the shafts 42 of the contrast elements 40 to the aforementioned rotating element, and - actuator means, suitable for causing angular movements of the rotating element relative to the stator 10.

The arrangement is such that an angular movement of the aforesaid rotatable element, caused by the actuator means, is transferred by the aforesaid transmission means to the shafts 42, causing a relative angular movement of the contrast elements 40.

In a preferred embodiment, the aforesaid transmission means comprise a substantially cam-follower coupling: in this case, preferably, the transmission means include an actuation arm made integral with the shaft 42 of a respective contrast member 40 and defining a cam profile, particularly in the form of a slot, and a cam follower, preferably in the form of a pin, which is integral with the aforementioned rotatable element and engaged with the cam profile of the respective actuating arm.

Referring in particular to the illustrated example, the contrasting elements 40 are rotatably mounted according to respective axes generally parallel to the X axis. In the example the aforesaid axes are identified by the shafts 42, with the latter being rotatably constrained in relative holes of the upper structure 16 and which are made integral, at their upper ends, to respective movable arms 43.

The arms 43, also angularly movable around the axes identified by the shafts 42, extend partially above a guide ring 44, essentially consisting of a disc mounted rotatably on the upper structure 16. In the example, the Guide ring 44, made of metallic material and suitably ground, rests on the structure 16 and has a central opening 44a coupled to the circular flange 32a of the bearing support 32, as can also be clearly seen in figure 10. As can also be seen from this figure 10, the guide ring 44 can be advantageously constrained in position on the upper structure 16 by exploiting suitable washers 33a coupled to the threaded members 33 used to fix the bearing support 32 in position.

The arms 43 are constrained to the guide ring 44, in correspondence with their part which extends over said ring, preferably with a cam-follower coupling. More particularly, referring to Figure 10, pins 45 are coupled to the upper face of the ring 44 (for example in the form of hardened shank screws or threaded pins with associated nut) arranged essentially along a circumference. Each of these pins 45 passes through a longitudinal slot 43a of a respective arm 43, in order to be able to slide freely therein.

In this way, as can be guessed, by means of a generic actuator - for example hydraulic or electric - it is possible to cause a rotation of the guide ring 44, thereby determining the angular displacement of the pins 45 and their consequent sliding in the within the scope of the relative slots 43a of the arms 43. The latter, being rotatably constrained to the upper structure 16 by means of the relative shafts 42, are then angularly displaced following the displacement of the pins 45 in the slots 43a, thereby causing a rotation of the same shafts 42, and therefore an angular movement of the body of the contrast elements 40. The concept is well exemplified by the comparison between figures 10, 11 and 12, which illustrate precisely three possible operating positions of the members 40.

In a particularly advantageous embodiment of the invention, the aforesaid actuation system is designed to vary the position of the contrast elements as a function of a fluid pressure upstream of the impeller inlet.

A possible realization in this sense is exemplified precisely in figures 10-12. Referring to figure 13, in it the turbine 1 is visible in plan from above, with some of the elements previously described, and in particular the upper structure 16 bearing the shafts 42 of the contrast elements 40, the arms 43, the Guide ring 44, the bearing support 32 and the fastening members 33 of this support, also used - together with the washers 33a - to constrain the guide ring 44 in position.

The distal end of the stem 47a of a hydraulic actuator, particularly a hydraulic cylinder, indicated as a whole with 47, is constrained to ring 44, particularly by means of an articulated support 46 (also visible in figure 2). The actuator 47 has a cylinder 47b, to which a relative support 47c is associated, and is connected by means of a duct 48 at a point upstream of the impeller inlet 23, for example in correspondence with a branch (not shown) of the inlet 11 of the stator of the stationary structure or of the supply duct D. In this way, the rod 47a slides in the cylinder 47b due to the effect of the pressure of the fluid that feeds the turbine 1.

Preferably, the actuator 47 is, as in the exemplified case, a double rod hydraulic cylinder, where the rod 47a has the distal end constrained to the guide ring 44 and where between the proximal end of the a spring 49 is operative. Preferably, an element 50 for adjusting the spring preload 49 is operatively associated with the proximal end of the stem 47a, for example in the form of a threaded ring nut, which also acts from feedback for the spring itself. By means of the adjustment element 50, or by adjusting the preload of the spring 49, it is possible to preset a â € œstandardâ € position of the contrast elements 40, which here is assumed to be an inoperative position, such that the impact on of these jets coming out from the peripheral part of the rotor 20, or with the fin-like body of the elements 40 extending approximately parallel to the direction of the jets J, as exemplified in figure 13.

This setting is made on the basis of the pressure of the fluid upstream of the rotor, in normal operating conditions of the hydraulic circuit that feeds the turbine 1. For example, referring to the example in figure 1, the setting of the normal position of the elements 40, operated by means of the adjustment element 50, is carried out on the basis of the pressure of the water normally present in the duct D of figure 1, which exists when the channeling section C1 is fed in the normal way (in other words , the pressure normally inlet from the tube 48 of the actuator 47 balances the elastic reaction of the spring 49 as determined by the element 50).

This condition is shown schematically in figure 10, from which it can be seen how the rod 47a of the cylinder 47 is maintained by the pressure of the fluid present in the duct 48 in a certain position, which corresponds to a certain position of the shafts 42 of the contrast elements 40, this position being determined by the position of the guide ring 44 and of the transmission means represented by the pins 45 and by the arms 43 with the relative slots 43a. In such a position (see also Figure 13), the angle with which the jets coming out of the inclined nozzles 70 strike the body of the contrast elements 40 is minimal.

In the event that a pressure drop occurs in the duct 48, the elastic reaction of the spring 49 determines a retraction of the distal end of the stem 47a (downwards, referring to figures 10-12), and therefore an angular movement of the Revolving element represented by the guide ring 44 (counterclockwise, referring to figures 10-12). The movement of the ring 44 causes the displacement of the relative pins 45 coupled to the slots 43a of the arms 43, with a consequent angular movement of the latter (clockwise, referring to figures 10-12) and therefore of the shafts 42, as exemplified in figure 11: in this way, a change in the position of the contrast elements 40 is obtained, that is, referring to the example described here, a position in which their contrast surface faces the outgoing fluid jets at a new angle from the rotor 20. The fact that these jets now affect the surface of the contrast elements 40 at a certain angle has the consequence that the rotor 20 rotates at a speed greater than that - if the elements 40 were in the initial position of Figures 10 or 13- would be determined only by the pressure of the fluid: in other words, therefore, in the condition of figure 11 and following the change in position of the control elements By contrast 40, a rotation speed of the rotor 20 is obtained substantially similar to that achieved in the â € œstandard pressureâ € condition of Figure 10.

Figure 12 illustrates the situation that occurs in the event of a further lowering of the supply pressure of the rotor 20, which corresponds to a more marked retraction of the rod 47a and more extended angular movements of the ring 44, of the pins 45, of the arms 43 and hence the shafts 42. In this way the contrast elements 40 are brought to assume a position such that the angle of incidence between the jets leaving the rotor 20 and the contrast surfaces 40a further increases and thereby determines a speed of the rotor greater than that which - if the elements 40 were in the position of figure 10 or that of figure 11 - would be determined by the fluid pressure alone: in other words, therefore, a rotation speed of the rotor 20 is obtained substantially similar to that achieved in the conditions of figures 10 and 11, despite the further pressure drop.

The function of the possibility of varying the incidence of the contrasting elements 40 is therefore that of maintaining a constant thrust in all pressure conditions of the inlet fluid.

In embodiments not shown, the actuation system described with reference to figures 10-12 can be operated by an electric actuator or by a pneumatic actuator, instead of by a hydraulic actuator, it being understood that the latter will in any case be controlled in a function of the pressure upstream of the impeller inlet, for example detected by suitable sensor means (in the case of electrical actuation) and / or by means of an arrangement similar to that illustrated (in the case of a pneumatic actuator).

In one embodiment it is also possible to provide an actuation system including two different actuators, of which a first actuator controlled according to the pressure of the fluid feeding the rotor 20 and a second actuator controlled by an external control system, particularly for check a working position of the first actuator.

Also such an embodiment is exemplified in figures 10-12, in which the actuator 47 has a movable support structure operatively associated with guide means, with a further actuator which can be controlled to vary the position of the aforesaid structure of support relative to the aforesaid guide means. More particularly, in the example, the support structure of the actuator 47 includes a slide 55, here associated with the support 47c, mounted slidingly on respective guides 56 stationary with respect to the slide, here so as to allow alternative sliding in the direction of the rod 47a of the actuator 47. A respective transmission is associated with the slide 55, configured to allow the position of the slide itself to be varied with respect to the guides 56 and therefore, ultimately, the axial position of the actuator 47 to be varied. an embodiment, such as that exemplified in Figures 10-12, the aforesaid transmission includes a cam member 57 cooperating with the slide 55, in particular with a lower side thereof, with this cam member which is associated with an actuation arm 58 angularly displaceable by means of a second actuator, not shown, for example an electric actuator having a rotatable shaft, schematized in 58a, which can be operated in two opposite verses. As you can guess, by activating for example the shaft 58a clockwise, the slide 55 is free to lower (referring to the case illustrated) on the guides 56, thereby causing a lowering of the actuator 47 as a whole. It will be appreciated that in this way, even in conditions of constant pressure in the tube 48 of the actuator 47, it is possible to cause an effect similar to that described above, which occurs in the event of a pressure drop. In other words, therefore, by varying the position of the actuator 47 the position of its stem 47a can be varied, thereby causing the angular movement of the guide ring 44, with the associated pins 45 and arms 43, and therefore, ultimately, of the shafts 42 of the contrast elements 40. It goes without saying that by causing an inverse rotation of shaft 58a and equal to the previous one, it is possible to re-establish the initial conditions. It will be appreciated that, in other embodiments not shown, the second actuation system described can be used regardless of the presence of the first actuation system described, also to replace its functionalities.

In figure 13 the turbine 1 is represented in plan, limited to some of its parts, in order to highlight the internal structure of the rotor. As already mentioned, in a preferred embodiment, the rotor 20 has a substantially disc shape, or a generally flattened circular shape, with the respective front, back and peripheral part which delimiting a hollow volume, preferably substantially cylindrical, into which extend the flow channels, indicated with 60 and 61.

In the exemplified embodiment, the flow channels 60 and 61 have an increasing passage section, most preferably increasing substantially progressively towards the peripheral part 21 of the rotor 20, in which the outlets including the nozzles 70 are located: referring in particular in the embodiment exemplified in Figure 13, the channels 60 and 61 have a plan profile at least approximately in the shape of a circular sector, open towards the impeller inlet. In an embodiment, such as the one shown, the height of the flow channels 60, 61 - defined by the front 22 and the rear 24 of the rotor (Figures 2 and 3), generally parallel to each other - is substantially constant, and inside the cylindrical volume of the rotor there are a plurality of radial walls, which laterally delimit the flow channels 60, 61 and which define between one their width dimension of the channels themselves, as mentioned, an increasing dimension towards the peripheral part 21 of the rotor 20.

In the preferred embodiment, the flow channels of the rotor comprise a plurality of primary channels, indicated with 60, and a plurality of secondary channels, indicated with 61. The primary channels 60 have an inlet closer to the impeller inlet, in axis to which the divider 25 and the diffuser 26 are located, with respect to the inlet of the secondary channels 61. The primary channels 60 and the secondary channels 61 preferably extend in a radial direction of the rotor 20, with each primary channel 60 being divided into a plurality of secondary channels 61 or with one or more secondary channels 61 which are alternated with primary channels 60. In the example, the internal volume of rotor 20 is divided into an even number of primary channels 60 (four channels 60 , in the example), each of which is divided into an odd number of secondary channels 61 (three channels 61, in the example), with a total of twelve output nozzles 70, each corresponding to a sub-channel 61 Alternative arrangements are obviously possible, with a different number of channels and sub-channels, particularly as a function of the diameter of the internal volume of the impeller.

The radial walls mentioned above are essentially configured as septa, preferably but not necessarily metallic, whose upper and lower edges are abutting on the inner side of the plates 22a and 24a (figure 3) of the rotor and whose outer edge is abutting on the inner side of ring 21a.

In the example, in which the primary channels and the secondary channels are provided, the aforesaid walls comprise first radial walls 62 and second radial walls 63 having different lengths, so that the first radial walls 62, longer, divide the internal cavity of the rotor 20 in a plurality of channels 60, while the second radial walls 63, shorter, divide the channels 60 into a plurality of channels 61.

The walls 62 and 63 preferably have edges with a profile such as to allow a relatively precise coupling thereof to the lower 22, upper 24 and peripheral parts 21 of the rotor. For example, referring also to Figure 3, in one embodiment the walls 62, 63 have an external end with a generally curved profile, in order to couple to an internal concave profile of the ring 21a which forms the peripheral part of the rotor. The walls 62 and 63 can for example be fixed in position with welding, or with threaded members or again by means of suitable seats defined on the internal side of the parts 21, 22 and 24 of the rotor structure.

As said, in the illustrated embodiment, the walls 62 and 63 have different lengths. In a preferred embodiment, the longer walls 62 extend substantially up to the impeller inlet 23. In this case, preferably, the walls 62 have an end close to the impeller inlet which is shaped so substantially congruent with the profile of at least one of the diffuser element 26 and the impeller inlet. For example, as can be seen in Figures 2 and 3, the end portion of the walls 62 close to the impeller inlet is here generally arched, so as to follow the profile of the member 26 and of the sleeve 23a (in one embodiment , the member 26 and / or the sleeve 23a can include surface recesses in which at least part of the arcuate portion of the walls 62) is coupled. In the illustrated embodiment, the corresponding end edge of the walls 62 is at a slight distance from the upper part of the flow divider 25, for example up to 1 cm away, so as not to create an obstacle with the rotation of the impeller. However, the distance between the aforementioned end edge and the divider 25 and / or the impeller inlet 23 is chosen according to the type of use of the turbine 1: in general terms, the length of the walls 62 is shorter ( and therefore the aforesaid distance is greater) when the application requires high speed or high pressure of the inlet fluid; for applications with lower speeds or pressures, the turbine will be set up with longer walls 62 (and therefore with a shorter distance of their inner edge from the diffuser 25 and / or from the inlet 23), as in the example exemplified.

In the example, the walls 62 and 63 are substantially straight, but the possible use of curved or otherwise shaped walls is included in the scope of the invention.

As can be seen from Figure 13, the primary channels 60 extend from the peripheral part 21 of the rotor 20 up to its central region, where the impeller inlet is located, not indicated here but in the axis where the divider 25 is located. and the diffuser 26, while the secondary channels 61 extend from the peripheral part 21 up to its intermediate region which is spatially comprised between the peripheral part 21 and the aforementioned central region.

The outlets of the flow channels, here in particular the outlets of the channels 61, comprise respective nozzles 70 in correspondence with the peripheral part of the rotor, and in particular in correspondence with its ring 21a. The nozzles 70 face with their respective outlets in a direction generally opposite to the predetermined direction of rotation of the rotor 20, for example with an inclination of about 90 ° with respect to the radius of the rotor, but the invention does not exclude the case of nozzles with variable or adjustable inclination, for example up to 110 °, with suitable construction variants. Preferably, as can be seen for example in Figures 2, 3 and 13, the outlets of the flow channels include an end section 71 upstream of the nozzles 70, having a profile at least partially tapered towards the respective nozzle. Preferably, the end sections 71 are defined immediately upstream of the joining areas between the walls 62, 63 and the ring 21a, with reference to the direction of rotation of the impeller. The shape of the outlet of the nozzles 70 can be different depending on the type of application: in general, for the use of the turbine in combination with low pressures and / or modest drop heights, the outlet of the nozzles 70 Ã ̈ preferably with buttonhole.

The operation of the turbine according to the invention is based on the exploitation of the kinetic mass of the fed fluid which, conveyed internally to its impeller 20, is suitably channeled outwards, to escape from the nozzles 70, of variable number in relation to the size of the turbine 1, thus creating the circular motion which is transmitted to the shaft 30. The outgoing flow is therefore not free, but is suitably conveyed and directed in a specific way, to obtain a centrifugal force reaction. The propulsive force that determines the rotation is therefore developed mainly internally to the impeller 20, creating a compression that increases the thrust in proportion to the radius of the impeller itself.

The pressure of the outgoing water, boosted by the nozzles 70, impacts against the contrast elements 40 and gives the rotational motion to the impeller 20 which increases above all due to the centrifugal action produced by the rotation of the impeller itself. The centrifugal force developed is decisive for compensating and minimizing the power losses, due to mechanical and hydrodynamic factors, typical of traditional turbines. In the impeller body 20 the incoming flow is axially divided by the divider 25 into the sub-flows directed on the deflector 26, which expands them uniformly, causing them to be channeled first into the flow channels 60 and then into the flow channels 61, of increase in output speed. The terminal sections 71 of the channels 60, 61 are defined in the ring 21a, to which the outlet and thrust nozzles 70 correspond. As a result of the thrust generated by the outlet pressure which has formed in the flow channels, the rotation of the impeller 20 takes place, increased by the centrifugal force which is automatically triggered. On the back 24 of the impeller is fixed the upright shaft 30, which is a single body with the impeller itself, receiving from this the rotary motion which in turn will be transmitted to the energy generator, here exemplified by an alternator, or to other connected device.

The regulation system previously described with reference to figures 10-12 essentially has the purpose of keeping the centrifugal thrust of the rotor 20 constant, with the impact of the water coming out of the nozzles 70 against the contrast elements 40: this in order to avoid possible power surges due to pressure variations of the incoming flow and / or to modify the power generated by means of the shaft 30, for example according to the needs of the electrical network powered by the alternator driven by the shaft 30 itself. compensation of pressure oscillations, and therefore of power, takes place with the bidirectional orientation of the contrast elements 40, in order to modify the angle of incidence of the jets coming from the nozzles 70, increasing or decreasing the thrust force exerted by the outgoing water. The regulation system acts automatically, being governed by the same pressure as the inlet flow. The same type of regulation can be obtained, regardless of variations in pressure or flow rate of the incoming fluid, by the actuation system here including slide 55, guides 56, cams 57, arm 58 and actuator 58a: in relation to power needs (for example of the electrical network or other device operatively connected to shaft 30), a sensor controls the actuator 58a which, by means of the cam 57, allows the actuator 47 to be moved.

Merely by way of indication, a small to medium-sized turbine of the type described can have an impeller with a diameter of about 400 mm and a height of about 60 mm, or with a substantially cylindrical internal hollow volume of about 380 mm in diameter and about 40 mm in height divided into four primary channels and twelve secondary channels as shown, with twelve nozzles 70 (as mentioned, the number of flow channels and nozzles can be variable in relation to the size of the turbine). Practical tests carried out by the Applicant with such a turbine have made it possible to ascertain that it has a very wide range of action, obtaining power generation already starting from inlet pressures of 0.8 bar with a flow rate of 5 liters / second and with a speed of rotation of the impeller from 200 rpm at speeds above 2,000 rpm, obtainable with an increase in fluid pressure, allowing to obtain an optimal working torque of 1,500 rpm, with a frequency of 50 Hz three-phase with synchronous alternator.

The turbine can obviously be sized to produce different quantities of energy, from small to high needs. Small-sized models find advantageous application, for example, in mountain areas where the cost of fixed power lines is very high and, on the other hand, there is a wide availability of modest but constant water supply. In this context, a simple ducting with a small tank allows to power a turbine 1 for the production of, for example, 3 Kwh, which can be easily increased in relation to the available water flow. The waste water from turbine 1 can be further used downstream by other turbines 1, depending on the flow rate available.

The turbine according to the invention finds a preferred application for the production of electricity through a generator (specifically an alternator), with non-polluting methods and using renewable sources, and suitable for water use with supply by means of a powered pipeline constant flow, which does not require complex hydraulic works. As mentioned, however, the turbine according to the invention can more generally be used in order to obtain mechanical energy available for the operation of other apparatuses.

The turbine according to the invention is particularly simple from a construction point of view, to the advantage of containing its construction costs and its reliability in operation, with modest maintenance and operating costs, and allows to obtain high yield ratios. even from modest fall heights.

It is clear that numerous variants are possible for the person skilled in the art to the turbine described as an example, without thereby departing from the scope of the invention as defined in the following claims.

The invention has been described with particular reference to a turbine operating with a fluid in the liquid state, but its feeding with gaseous fluids, for example steam, is not excluded from the scope of the invention itself. In the case of use for the production of electricity, synchronous or asynchronous alternators, depending on the type of application, can be coupled directly to the turbine shaft or with the interposition of speed variators for inverter applications. In embodiments not illustrated, the stator 20 can have a simpler structure than the one exemplified here: it will be appreciated, for example, that in other embodiments the lower structure 15 can be omitted. It goes without saying that structures 15 and 16 do not necessarily have to have a circular external profile, although this profile is preferable; the same applies to the front 22 and the rear 24 of the rotor.

Claims (15)

CLAIMS 1. A turbine, comprising a stationary structure (10), having an inlet (11) for connection to a supply line (D) of a flow of a fluid, and an impeller (20), having a hollow mobile structure ( 21-24) rotatably supported by the stationary structure (10) to rotate according to a respective axis (X), the mobile structure having a front (22), a rear (24) and a peripheral part (21), wherein the mobile structure (21-24) has a plurality of flow channels (60, 61) extending from the peripheral part (21) of the mobile structure (21-24) towards a central region thereof, in which the mobile structure (21-24) has, at a central region of its front (22), an impeller inlet (23) in fluid communication with the inlet (11) of the stationary structure (10) and with the flow channels (60, 61), the impeller inlet (23) preferably substantially facing an end section of the inlet (11) of the stationary structure (10), and in which a turbine shaft (30) is operationally connected to the rear (24) of the mobile structure (21-24), in such a way that the fluid entering the turbine (1) from the inlet (11) of the stationary structure (10) flows inside the mobile structure (21-24) through the impeller inlet (23) , to flow into the flow channels (60, 61) and then come out in the form of jets (J) from respective outlets (70, 71) at the peripheral part (21) of the mobile structure (21-24), thereby causing the rotation of the latter, and therefore of the turbine shaft (30), in which the turbine (1) comprises, at the impeller inlet (23), a flow divider (25) supported in a fixed position by the stationary structure (10) and configured to divide the flow of the fluid entering the structure mobile (21-24) in a plurality of sub-streams (F), and in which the rear (24) of the mobile structure (21-24) has, in one of its central regions, a substantially conical deflector member (26) which is generally facing the impeller inlet (23) and which extends towards the flow divider (25), the deflector member (26) being configured to direct the sub-flows (F) towards the flow channels (60, 61). The turbine according to claim 1, wherein the front (22), the rear (24) and the peripheral part (21) of the mobile structure (21-24) delimit a hollow volume of the mobile structure (21-24) in which the flow channels (60, 61) of said plurality extend, the front (22) and the rear (24) of the mobile structure (21-24) being preferably substantially parallel to each other, and in which the plurality of flow (60, 61) includes: - a plurality of channels (60) extending from the peripheral part (21) of the mobile structure (21-24) up to a central region thereof, and - a plurality of channels (61) which extend from the peripheral part (21) of the mobile structure (21-24) up to an intermediate region thereof which is spatially comprised between the peripheral part (21) and the said central region. 3. The turbine according to claim 1 or claim 2, wherein the flow divider (25) extends at least partially inward from the mobile structure (21-24), towards a tip of the deflector member (26 ), the top of the flow divider (25) preferably being at a slight distance from the tip of the deflector member (26) or projecting into a housing of the tip of the deflector member (26). The turbine according to claim 3, wherein the flow divider (25) has a generally tapered configuration in an upper region thereof. The turbine according to any one of the preceding claims, in which a deflector member (26) has a substantially conical exponential profile. The turbine according to any one of the preceding claims, wherein the flow divider (25) includes a tubular jacket (25a), preferably cylindrical, having an upper end and a lower end, and one or more dividing walls (25b) which divide an internal volume of the tubular jacket (25a) into a plurality of sub-chambers (25c), preferably sub-chambers having a substantially circular sector section, one or more dividing walls (25b) preferably projecting axially from the jacket tubular (25a) at least at its upper end. The turbine of claim 6, wherein the dividing wall (25b), or each dividing wall (25b), has a generally tapered top, with an upper edge extending between a top of the partition (25b ) and an upper edge of the tubular jacket (25a). The turbine according to claim 6 or claim 7, wherein the partition wall (25b), or each partition wall (25b), has a generally flat upper end. The turbine according to any one of the preceding claims, in which the mobile structure (21-24) has a substantially disc shape, the front (22), the rear (24) and the peripheral part (21) of the mobile structure (21 -24) delimiting a substantially cylindrical hollow volume which is divided into the flow channels (60, 61). 10. The turbine according to any one of the preceding claims, in which the impeller inlet (23) includes a tubular portion (23a) generally coaxial to the inlet (11) of the stationary structure (10) and to the axis of rotation (X) of the mobile structure (21-24), the tubular portion (23a) having in particular a first end, with a diameter preferably substantially corresponding to a terminal diameter of the inlet (11) of the stationary structure (10), and a second end which has a generally flared profile towards the inside of the mobile structure (21-24). The turbine according to any one of the preceding claims, wherein the stationary structure (10) includes a substantially disc-shaped portion, defining a housing (C) for the mobile structure (21-24). The turbine according to any one of the preceding claims, in which the turbine shaft (30) is integral with the rear (24) of the mobile structure (21-24) and with a rear (16) of the stationary structure (10 ) A support (32) for housing for guide bearings (31a) of the turbine shaft (30) is integral. The turbine according to any one of the preceding claims, wherein the impeller inlet (23) includes a first tubular part (23a) engaged in a second tubular part (13) of the stationary structure (10), between the first and the second tubular part (23a; 13) being operatively arranged sealing means including at least one gasket (14a) supported by a gasket-holder ring (14). The turbine according to any one of the preceding claims, wherein the plurality of flow channels (60, 61) comprises a plurality of primary channels (60) and a plurality of secondary channels (61), the primary channels (60) having an inlet closer to the impeller inlet (23) than the inlet of the secondary channels (61), the primary channels (60) and the secondary channels (61) extending preferably in a radial direction of the mobile structure (21- 24), and in which each primary channel (60) is subdivided into a plurality of secondary channels (61) or one or more secondary channels (61) are alternated with the primary channels (60). The turbine according to any one of the preceding claims, comprising a plurality of contrast elements (40), supported by the stationary structure (10) in a position generally facing the peripheral part (21) of the mobile structure (21-24), in which the contrast elements (40) are mounted on the stationary structure (10) in a mobile way, to vary the position of one of their surfaces (40a) with respect to jets (J) of the fluid leaving the flow channels (60, 61), in at least one position of the contrast elements (40) the said surface (40a) being capable of being hit by the aforementioned jets (J), and in which the turbine (1) further comprises at least one actuation system (47; 47, 55 -58) to vary in a controlled way the position of the contrast elements (40).