Water turbine

Abstract

A water turbine system, comprising: - a reaction turbine (101) comprising a plurality of nozzles (101n), - an action turbine (102) comprising a plurality of water collection elements (102e) and configured to be fed by said reaction turbine (101); wherein the spatial configuration of said reaction turbine (101) and of said action turbine (102) is such that water exiting each nozzle (101n) of said plurality of nozzles (101n) hits at least a first respective water collection element (102e) of said plurality of water collection elements (102e) with a predetermined angle of incidence (α1") and determines: - a rotation of said reaction turbine (101) with a reaction turbine speed (ωg), and - a rotation of said action turbine (102) with an action turbine speed (ωp); a geometry of said reaction turbine (101) and of said action turbine (102) being configured to keep at least said angle of incidence (α1") and / or at least a ratio (r) between said reaction turbine speed (ωR) and said action turbine speed (ωA), or between a speed (ωARAin) of the action turbine (102) water exiting from at least one of said plurality of water collection elements (102e) and a speed (v2) of the water exiting from at least one of said plurality of nozzles (101n), within at least one respective predetermined range of angles of incidence (α1", min – α1", max) and / or of range of ratios (rmin – rmax) maximizing an efficiency of the turbine system.

Description

[0001] GAI1P4W0

[0002] WATER TURBINE

[0003] Field of the art

[0004] The disclosure refers to the field of the turbines, in particular water turbines.

[0005] Background

[0006] Water turbines are very well diffused in the field of production of electric energy. In hydroelectric plants, water turbines exploit the water flowing from a predetermined height above the turbine to convert the energy of the water flow to a rotational force that forces a generator connected to the turbine in rotation, thereby producing electric energy.

[0007] Maximization of efficiency is desirable; therefore several types of turbines have been designed in order to maximize the efficiency according to the specific configuration of the penstock feeding the turbine. For instance, when dealing with low-head applications, Kaplan turbines are preferred to Francis turbines. Higher heads are managed by Francis turbines, which have the drawback of a limited range of setting, in order to be highly efficient.

[0008] In alpine applications, where high water heads are combined with low water flows, Pelton turbines are typically used.

[0009] Several types of combined turbines have been developed, in order to combine the advantages of each known type of turbine to increase the range of operative conditions at which efficiency is maximized.

[0010] Summary

[0011] Applicant has conceived and studied a particular model of water turbine system which is provided with a reaction turbine and an action turbine, the first one feeding the second. After detailed studies, it has been discovered that there are specific ranges in the geometry of the turbine system at which the efficiency is maximized.

[0012] The turbine system of the present disclosure, when designed according to the hereinafter disclosed model, is highly efficient and then contributes to maximize the amount of electric energy that can be produced given a predetermined amount of flow rate.

[0013] The present disclosure relates to a water turbine system whose principal aspects are hereinafter disclosed. The following aspects may be combined together in any suitable form and / or may be combined with portions of the description and / or with one or more of the subsequent claims.

[0014] According to an aspect, it is herewith disclosed a water turbine system, comprising:

[0015] - a reaction turbine (101) comprising a plurality of nozzles (lOln),

[0016] - an action turbine (102) with a plurality of water collection elements (102e) and configured to be fed by said reaction turbine (101); GAI1P4W0 wherein the spatial configuration of said reaction turbine (101) and of said action turbine (102) is such that water exiting each nozzle (lOln) of said plurality of nozzles (lOln) hits at least a first respective water collection element (102e) of said plurality of water collection elements (102e) with a predetermined angle of incidence (a ) and determines:

[0017] - a rotation of said reaction turbine (101) with a reaction turbine speed (o>R), and

[0018] - a rotation of said action turbine (102) with an action turbine speed (o> A); a geometry of said reaction turbine (101) and of said action turbine (102) being configured to keep at least said angle of incidence (a ) and / or at least a ratio (r) between said reaction turbine speed (o>R) and said action turbine speed (o> A), or between a speed (<jjARALn) °f said action turbine (102) and a speed (V2) of the water exiting from at least one of said plurality of nozzles (lOln), within at least one respective predetermined range of angles of incidence (ar, min - ar, max) and / or of range of ratios (rmin - rmax) maximizing an efficiency of the turbine system.

[0019] According to a further non-limiting aspect, the speed (<jjARALn) °f said action turbine (102) is the speed of an inner portion of said action turbine (102), preferably of an innermost portion of said action turbine (102).

[0020] According to a further non-limiting embodiment, said geometry is a combined geometry of said reaction turbine (101) and of said action turbine (102).

[0021] According to a further non-limiting aspect, the reaction turbine (101) and the action turbine (102) are co-axial.

[0022] According to a further non-limiting aspect, said water exiting each nozzle (lOln) of said plurality of nozzles (lOln) determines a rotation of said reaction turbine (101) in a first rotation direction and of said action turbine (102) in a second rotation direction opposed to said first rotation direction.

[0023] According to a further non-limiting aspect, said reaction turbine (101) and said action turbine (102) are substantially co-planar.

[0024] According to a further non-limiting aspect, at least part of the nozzles (lOln) of said plurality of nozzles (lOln) in use spray water along a direction which is parallel to, and / or lies on, a plane on which the reaction turbine (101) and / or the action turbine (102) in use rotate.

[0025] According to a further non-limiting aspect, at least a part of the nozzles (lOln) of said plurality of nozzles (lOln) in use spray water along a direction which is inclined with respect to, and / or does not lie on, a plane on which the reaction turbine (101) and / or the action turbine (102) in use rotate.

[0026] According to a further non-limiting aspect, said reaction turbine (101) and said action turbine (102) are configured to rotate on a plane which is substantially horizontal or substantially inclined with respect to a horizontal plane and which is optionally a vertical plane.

[0027] According to a further non-limiting aspect, the turbine system comprises a water inlet conduit (103) feeding said reaction turbine (101). GAI1P4W0

[0028] According to a further non-limiting aspect, said water inlet conduit (103) is arranged at a bottom portion of said reaction turbine (101) and / or feeds said reaction turbine (101) with water flowing upwardly, in particular with water flowing along a substantially vertical direction.

[0029] According to a further non-limiting aspect, said water inlet conduit (103) is arranged at a lateral portion of said reaction turbine (101) and / or feeds said reaction turbine (101) with water flowing from a left side or a right side direction, in particular with water flowing along a substantially horizontal direction. According to a further non-limiting aspect, said water inlet conduit (103) is at least partially centered on a rotation axis of said reaction turbine (101) and of said action turbine (102).

[0030] According to a further non-limiting aspect, the turbine system comprises an output shaft, the reaction turbine (101) and the action turbine (102) being connected to said output shaft, preferably being connected to said output shaft by means of a transfer case coupling a rotating torque in use provided by a shaft of said reaction turbine (101) with a rotating torque in use provided by a shaft of said action turbine (102), optionally the transfer case comprising a free wheel allowing a reciprocal free rotation between said shaft of said reaction turbine (101) and said shaft of said action turbine (102).

[0031] According to a further non-limiting aspect, said ratio (r) between the speed (<jjARALn) °f said action turbine (102) and the speed (V2) of the water exiting from at least one of said plurality of nozzles (lOln) is [0,2 - 0,3] or [0,4 - 0,6],

[0032] According to a further non-limiting aspect, said range of ratios (rmin- rmax) between said reaction turbine speed (a)R) and said action turbine speed (a) A) is between [0,2 - 1] or between [0,3 - 0,9], According to a further non-limiting aspect, said range of ratios is independent of a flow rate of water flowing from said plurality of nozzles (lOln).

[0033] According to a further non-limiting aspect, said range of angles of incidence (a ,min- ar, max) is [30 - 40]°, optionally [32 - 38]°, or is [42 - 58]°, optionally [45 - 55]°, optionally wherein said range of ratios is independent of the flow rate of water flowing from said plurality of nozzles (lOln).

[0034] According to a further non-limiting aspect, at a given angle of incidence, the efficiency increases with a water flow rate at said water inlet conduit (103).

[0035] According to a further non-limiting aspect, the turbine system has a predetermined water flow rate above which the efficiency decreases, preferably independently of the given angle of incidence.

[0036] According to a further non-limiting aspect, the turbine system has a predetermined water flow rate above which the efficiency decreases, preferably independently of the given angle of incidence with respect to an efficiency at a same angle of incidence and below said predetermined flow rate.

[0037] According to a further non-limiting aspect, said each water collection element (102e) of said plurality of water collection elements (102e) is provided with a collection surface concave in a radially inward direction. GAI1P4W0

[0038] According to a further non-limiting aspect, each water collection element (102e) of said plurality of water collection elements (102e) comprises a water receiving portion and a water discharge portion. According to a further non-limiting aspect, the water receiving portion is configured to receive said water exiting said nozzle (lOln).

[0039] According to a further non-limiting aspect, said water discharge portion is configured to let water flow away from said water collection element (102e).

[0040] According to a further non-limiting aspect, the water receiving portion is a front portion in the sense of rotation of said action turbine (102).

[0041] According to a further non-limiting aspect, the water discharge portion is a back portion in the sense of rotation of said action turbine (102).

[0042] According to a further non-limiting aspect, the water collection element (102e), optionally said water receiving portion and said water discharge portion, comprises an inner face, and an outer face. According to a further non-limiting aspect, the inner face is in use hit by the water flow.

[0043] According to a further non-limiting aspect, the outer face is substantially opposed to the inner face. According to a further non-limiting aspect, said inner face is directed backwards in the sense of rotation of the action turbine (102) and the outer face is directed along the sense of rotation of the action turbine (102).

[0044] According to a further non-limiting aspect, said water discharge portion is configured to discharge water to a zone which is radially outer with respect to said action turbine (102) and / or below said action turbine (102).

[0045] According to a further non-limiting aspect, the water receiving portion defines a curved shape with a first radius, wherein the water discharge portion defines a curved shape with a second radius. According to a further non-limiting aspect, the first radius being smaller than the second radius.

[0046] According to a further non-limiting aspect, each nozzle of said plurality of nozzles (lOln) has a substantially circular cross section.

[0047] According to a further non-limiting aspect, the water flowing outside each nozzle of said plurality of nozzles (lOln) defines an overall cross section substantially equal to at least 50%, preferably equal to at least 60%, more preferably substantially equal to at least 75% of an overall surface of each water collection element (102e) of said plurality of water collection elements (102e).

[0048] According to a further non-limiting aspect, the water flowing outside each nozzle of said plurality of nozzles (lOln) defines an overall cross section which is below 50%, or below 40%, or below 30% of an overall surface of each water collection element (102e) of said plurality of water collection elements (102e).

[0049] According to a further non-limiting aspect, the reaction turbine (101) comprises:

[0050] - a central portion (105); GAI1P4W0

[0051] - a plurality of hollow arms (110) having a first end connected to said central portion (105) and a second end opposite to the first end realizing said nozzle (lOln).

[0052] According to a further non-limiting aspect, each hollow arm comprises a first portion (107), in particular a radially inner portion, directed along a radial direction with respect to said central portion (105), and comprises a second portion (108), in particular a radially outer portion, directed along a direction inclined with respect to said radial direction.

[0053] According to a further non-limiting aspect, a numerosity of said plurality of water collection elements (102e) and a numerosity of said plurality of nozzles (lOln) are mutually correlated.

[0054] According to a further non limiting aspect, the numerosity of said plurality of water collection elements (102e) is a predefined multiple of the numerosity of said plurality of nozzles (lOln).

[0055] According to a further non-limiting aspect, the water turbine system comprises or is connected to an electric generator.

[0056] According to a further non-limiting aspect, said generator is connected to a load.

[0057] According to a further non-limiting aspect, the water turbine system is configured and destined to cope with variations of said load, in particular with variations of a resistive and / or reactive impedance of said load.

[0058] According to a further non-limiting aspect, said electric generator is connected to at least one between said reaction turbine (101) and / or said action turbine (102), preferably simultaneously to said reaction turbine (101) and said action turbine (102), by means of a connection shaft (111), said generator being configured to produce electric energy to feed to a load, preferably wherein said load is an energy distribution network.

[0059] According to a further non-limiting aspect, said generator is configured to rotate at a constant generator speed, or is configured to rotate at a variable generator speed.

[0060] According to a further non-limiting aspect, the water turbine system comprises a generator speed regulator, configured to keep said generator speed within a predetermined range.

[0061] According to a further non-limiting aspect, said generator is a three-phase generator and / or is a squirrel cage generator.

[0062] According to a further non-limiting aspect, said generator is opposed with respect to said water inlet conduit (103).

[0063] According to a further non-limiting aspect, a generator's rotor is connected to said output shaft.

[0064] According to a further non-limiting aspect, the water turbine system comprises a power unit configured to electronically detect at least one, preferably all, among a voltage, frequency, phase sequence, phase angle of the voltage on said load.

[0065] According to a further non-limiting aspect, said power unit is configured to cause an adaptation of a rotation speed of said water turbine and / or of said generator, in such a way to make the at least one, GAI1P4W0 preferably a 11, among a voltage, frequency, phase sequence, phase angle of the voltage of the electric energy to feed to said load, in particular to said electric energy distribution network, match the at least one, preferably all, among a voltage, frequency, phase sequence, phase angle of the voltage on said load.

[0066] According to a further non-limiting aspect, the power unit comprises a power switch connected at an outlet of said generator.

[0067] According to a further non-limiting aspect, said power unit is configured to:

[0068] - keep said power switch in an open configuration, or to cause an automatic switching of said power switch, when at least one, preferably all, among a voltage, frequency, phase sequence, phase angle of the voltage of the electric energy to feed to said load lie outside or go outside a safety range of closeness to the at least one, preferably all, among a voltage, frequency, phase sequence, phase angle of the voltage on said load, or to keep said power switch during a synchronization phase, and

[0069] - switch to a closed configuration, or to keep said configuration, of said power switch, when at least one, preferably all, among a voltage, frequency, phase sequence, phase angle of the voltage of the electric energy to be fed to said load lie inside or go inside a safety range of closeness to the at least one, preferably all, among a voltage, frequency, phase sequence, phase angle of the voltage on said load, or after said synchronization phase.

[0070] According to a further non-limiting aspect, at least a number of said nozzles (lOln) and / or an opened or closed configuration thereof, and / or a number of said water collection elements (102e), and / or a relative position and / or orientation between said nozzles (lOln) and / or water collection elements (102e), is adaptable, preferably operatively adaptable, to a water flow rate at said water inlet conduit (103).

[0071] According to a further non-limiting aspect, said plurality of nozzles (lOln) is removably installed and / or operatively installed in a removable way, and / or is at least partially selectively closeable in such a way to adapt a flow rate of the plurality of nozzles (lOln) and / or of said reaction turbine (101) and / or wherein said plurality of water collection elements (102e) is removably installed and / or operatively installed in a removable way.

[0072] According to a further non-limiting aspect, the water turbine system comprises a water collection reservoir arranged at a bottom portion and / or below said reaction turbine (101) and said action turbine (102).

[0073] According to a further non-limiting aspect, the water collection reservoir is configured to house at least part of the water that exits from the plurality of water collection elements (102e).

[0074] According to a further non-limiting aspect, the water collection reservoir is provided with an outlet port, a bottom wall and a lateral wall and preferably wherein said lateral wall is substantially circular. GAI1P4W0

[0075] According to a further non-limiting aspect, said outlet port being arranged in correspondence of the lateral wall.

[0076] According to a further non-limiting aspect, the water collection reservoir is centered on the rotation axis of the reaction rotor (101) and / or of the action rotor (102), and preferably houses at least a part of the shaft of said reaction rotor (101) and / or of said action rotor (102).

[0077] Figures

[0078] A preferred model of water turbine system is hereinafter disclosed with reference to the annexed figures; a brief description thereof is herewith provided.

[0079] Figure 1 shows a partial section view of a turbine system according to the present disclosure.

[0080] Figure 2 shows a schematic view of torque forces exerted on a first rotor and on a second rotor of a turbine system.

[0081] Figure 3 shows a schematic diagram of a reaction rotor of a turbine fed from a bottom portion.

[0082] Figure 4 shows a forces diagram when a water spray exiting a nozzle of an inner rotor impacts on a water collection element of an outer rotor.

[0083] Figure 5 shows a diagram relating to radiuses and angles of a water collection element part of an outer rotor of the turbine system of the present disclosure.

[0084] Figure 6 shows a profile diagram for the water collection element part of the turbine system of the present disclosure.

[0085] Figure 7 shows an efficiency diagram of a studied model of the turbine according to the present disclosure, as a function of an effective angle of impact of a water spray on a water collection element; in the diagram, several curves show the behavior of the turbine system according to a variety of water flow rates.

[0086] Figure 8 shows another schematic view of a part of the water turbine assembly according to the present disclosure.

[0087] Figure 9 and figure 10 show the volumetric efficiency as a function of the ratio between the absolute speeds of the water collection element / water jet.

[0088] Detailed description

[0089] In figure 1, reference number 100 identifies a water turbine system according to the present disclosure.

[0090] The turbine system is provided with two rotors, that define a reaction turbine 101 and an action turbine 102.

[0091] As shown in figure 1, the reaction turbine 101 comprises a plurality of nozzles lOln, which in use direct a flow of water towards the action turbine. GAI1P4W0

[0092] The action turbine 102 comprises a plurality of water collection elements 102e and is fed by the reaction turbine.

[0093] Water comes from the water inlet conduit 103 feeding said reaction turbine 101, preferably from a bottom portion thereof. In fact, the preferred embodiment of the water turbine assembly according to the present disclosure is provided with a water inlet conduit 103 that feeds water upwardly, from a lower height up to an upper height at which the rotor of the reaction turbine 101 is arranged. The force of the water causes a flow of water that drives the reaction turbine 101 in rotation.

[0094] Another embodiment, not shown in the annexed figures, is provided with a water inlet conduit 103 which is arranged on a left side or right side of the reaction turbine 101, and thus feeds said turbine laterally. A specific version of such embodiment is such that the water inlet conduit 103 is configured to feed the reaction turbine 101 with a water flow aligned along a substantially horizontal direction. The reaction turbine 101 comprises a central portion 105 which acts as a water collector and which is connected to the inlet conduit 103; a plurality of arms 110 radially depart from the central portion 105 of the reaction turbine and are directed to a radially outer portion thereof.

[0095] The end portion of the overall amount of the arms describes a circumference which describes the maximum diameter of the reaction turbine 101.

[0096] In a preferred embodiment, while the inner portion of the arms 110 extends in a radial direction with respect to the central portion 105 of the reaction turbine 101, i.e. in a direction which is orthogonal to the tangent of the circumference of the central portion 105 in correspondence of which the arm is arranged, the end portion (outer portion) of each of the arms 110 is directed to a direction which is sensibly inclined with respect to such radial direction. As a result, when the water exits the arm, it causes a reaction force inclined with respect to the radial direction, and this force causes a rotation of the reaction turbine 101 around its rotation axis X.

[0097] The overall number of arms 110 can be even or uneven, according to the specific configuration. In any case, optionally in order to cause an equilibrated construction, the arms 110 are uniformly distributed on the perimeter of the central portion 105 of the reaction turbine 101.

[0098] The cross section of the conduit realized by the arms 110 is preferably circular. Such cross section may be constant throughout the extension of the arm, or in contrast may reduce progressively at the outer portion.

[0099] In general, thus an embodiment of the turbine is such that the arms 110 realize a conduit which has a first cross section or diameter and a second cross section or diameter; the second cross section or diameter, being in correspondence of an outer, perimetral, portion of each of the arms 110 of the plurality of arms 110 is lower than the first cross section or diameter, being in correspondence of an inner portion 107 of each of the arms 110 of the plurality of arms 110. GAI1P4W0

[0100] The shape of the outer portion 108 of the arms 110 is such that to cause in use a water flow which is substantially tubular, i.e. ideally with no conicity or in any case with a low conicity; this causes a more precise guidance of the water flow towards the water collection elements 102e.

[0101] As a result, the water collection elements 102e, when hit by the water flow, receive a force that causes a rotation of the action turbine 102 in a direction which is opposite to the direction of rotation of the reaction turbine 101; thus, the reaction turbine 101 and the action turbine 102 are counter-rotating.

[0102] Water exiting from each of the nozzles lOln hits at least a first respective water collection element 102e momentarily arranged in front thereof with a predetermined angle of incidence a which may variate in a range that encompasses a minimum angle of incidence ar, min and a maximum angle of incidence ar, ax- Such angle of incidence may be measured with respect to the orthogonal line to the radius line at the point of impact on the water collection element 102e. Such angle of incidence is measured on a plane on which the action turbine 102 is arranged and rotates.

[0103] The wording "hits at least a first respective water collection element 102e" means that while some embodiments may be such that the water exiting from one nozzle lOln hits a single water collection element 102e, in some other embodiments the water exiting from one nozzle lOln hits a plurality of water collection elements 102e at the same time.

[0104] It is noted that in the preferred embodiment, each nozzle lOln of the plurality of nozzles lOln sprays water in a direction which is parallel to, and / or lies on, the plane at which the action turbine 102 and / or the reaction turbine 101 rotate(s). This technical feature shall not be considered limiting, since the present disclosure, concerning embodiments wherein the action turbine and reaction turbine rotate on different but parallel planes, in addition describes nozzles lOln spraying in use water in a direction which is not parallel to, and / or does not lie on, the plane on which the action turbine 102 and / or the reaction turbine 101 rotate(s).

[0105] As it appears clear from figure 1, the reaction turbine 101 and the action turbine 102 rotate around a same rotation axis X which, preferably, is substantially vertical. It results that the reaction turbine 101 and the action turbine 102 are configured to rotate on planes which are substantially horizontal.

[0106] More in detail, in a non-limiting embodiment, the action turbine 102 and the reaction turbine 101 are co-planar; precisely, the outlet of each of the arms 110 of the reaction turbine 101, that realize the nozzles lOln, are arranged on the same plane at which the water collection elements 102e are arranged.

[0107] The water collection elements 102e may be provided with an inner face which is at least partially or optionally overall directed towards the nozzles lOln (i.e. may be provided with a surface lying on a plane orthogonal to a radius joining the nozzle with the water collection element) or may be at least partially or optionally overall directed upwards, i.e. above the nozzles lOln of the reaction turbine 101 or downwards, i.e. below the nozzles lOln of the reaction turbine. GAI1P4W0

[0108] Applicant has also conceived embodiments of the turbine assembly 100 wherein the reaction turbine 101 and the action turbine 102 rotate on a substantially vertical plane, and embodiments with a horizontal or vertical rotation plane wherein the reaction turbine 101 and the action turbine 102 are not co-planar.

[0109] Resuming, in use the reaction turbine 101 rotates with an own reaction turbine speed o>R, while the action turbine 102 rotates with an own action turbine speed J A. Such speeds are angular speeds (rad / s).

[0110] In the following description reference is made to a ratio r which is defined as follows:

[0111] As it will be clearer from the following disclosure, the geometry of the reaction turbine assembly is configured to keep at least said angle of incidence a and / or at least the ratio r between said reaction turbine speed JRand said action turbine speed Jpwithin at least one respective predetermined range of angles of incidence [a , min - ar, max] and / or of range of ratios rmin - rmax maximizing an efficiency of the turbine system.

[0112] The range of ratios (rmin - rmax) between the reaction turbine speed (o>R) and said action turbine speed (o> A) may be between [0,2 - 1] or between [0,3 - 0,9],

[0113] It is noted that the above ratio may related to the ratio between a water speed exiting from at least one of the plurality of water collection elements 102e and a water speed exiting from at least one of the plurality of nozzles lOln. In this latter case, the ratio r between the speed jARAm°faninner portion of the action turbine 102, in particular of the innermost portion of the action turbine 102, and a speed V2 of the water exiting from at least one of the plurality of nozzles lOln is [0,2 - 0,3] or [0,4 - 0,6].

[0114] The speed of the plurality of water collection elements 102e is jARAmwhile the speed of the water out of the nozzle lOln is given

[0115] The aforementioned geometry is the geometry, i.e. combined shape and / or spatial orientation, of the reaction turbine 101 and of the action turbine 102 when considered together.

[0116] When the reaction turbine speed o>Rand the action turbine speed are constant, the net torque acting on the reaction turbine 101 is zero, i.e. the active torque is equal to the reaction torque.

[0117] As schematically shown in figure 2, the reaction turbine generates an active torque MR[Nm] and the action turbine 102 generates an active torque MA [Nm],

[0118] The active torque MA is transmitted to the reaction turbine by means of gears. A drag torque MF[Nm] may derive from water sprays that after having hit the water collection element 102e hit back one of the arms 110 of the reaction turbine 101. GAI1P4W0

[0119] A drag torque Mext [Nm] is further applied on the reaction turbine 101: this torque derives from the mechanic energy absorbed by the electric generator connected thereto. A further drag torque MF[Nm] may be further present at the reaction turbine 101 shaft due to the friction force that may be caused by the gears and bearings 107.

[0120] It is noted that the drag torque Mext [Nm] applied by the electric generator in turn has:

[0121] - a first component that is due to mechanical frictional forces determined during the rotation of a rotor portion of the electric generator;

[0122] - a second component that is due to the current absorption of the load connected to the generator. According to the specific conditions present on the energy distribution network, at least the second component may variate suddenly.

[0123] The electric generator may be provided with a stator portion and a rotor portion. The generator may be an axial flux-type electric generator or a radial flux-type electric generator. When in the form of a radial flux-type generator, stator portion is arranged outside the rotor portion, and substantially encloses the rotor portion. When in the form of axial flux-type electric generator, the stator portion may be juxtaposed in front of the rotor portion.

[0124] It results that: l 0 MR+ UMA- Mext- MF- MF= 0

[0125] In the previous formula,

[0126] The water flowing into the water inlet conduit 103 is provided with a speed v0[m / s] and is then subdivided in the arms 110 that end with the nozzles 102n. vi [m / s] is the relative speed of the water flow in each arm. Such speed is substantially equivalent for all the arms 110 of the reaction turbine 101.

[0127] Reference is made to the reaction turbine 101 schematically shown in figure 3, provided with three arms each ending with a respective nozzle lOln.

[0128] As considered above, water moves from a first (lower) height zo [m] to an upper height Z2 [m], and from Bernoulli's equation it results: wherein po is the pressure detected at height zo, Y is the specific weight of water, J0[m / s] is the speed of the water in the water inlet conduit 103, Z2 is the height of the nozzles lOln, V2R is the relative speed of the water with respect to the nozzle lOln, JRis the rotation speed of the reaction turbine and RRis the radius [m] of the reaction turbine 101. Hi0SSis the sum of the head losses as follows: GAI1P4W0 wherein:

[0129] - the first two addends are the losses distributed along the conduits having diameters Do and Di,

[0130] - the third addend is the loss concentrated in the curve on the feeding pipe of the turbine (not present in the figure);

[0131] - the fourth added is the loss at the subdivision of the water flow in correspondence of the center portion of the reaction turbine 101;

[0132] - the fifth addend is the final curve of the arm;

[0133] - the sixth addend us the loss at the nozzle lOln; ^bend.o, ^ug are non-dimensional coefficients of loss.

[0134] The coefficient A has been calculated by using the Colebrook-White formula: wherein:

[0135] — e / D is the relative roughness of the inner surface of the conduit realized by each of the arms 110 of the reaction turbine 101;

[0136] - Re is the Reynolds number of conduit. wherein D is the diameter of the cylindrical portion of each of the arms 110 and water inlet conduit 103.

[0137] Furthermore: wherein

[0138] ^ugis the loss coefficient of the nozzle, and <pugis the efficiency of the nozzle lOln.

[0139] The input power of the turbine system, evaluated at the height at which the nozzles lOln of the reaction turbine 101 lie (z2 [m]) corresponds to: wherein Az = z2— zois the positive difference of height between the height of the nozzles and the height at which the pressure is measured on the feeding pipe of diameter Do.

[0140] The mechanical pressure extracted from the turbine may thus be considered as follows:

[0141] The mechanical efficiency may thus be considered as: GAI1P4W0

[0142] Supposing that a generator is connected to the reaction turbine 101 through a connection shaft 111 t) ' arranged on the top of the turbine assembly 100, and has a transmission ratio mG= — with the reaction turbine 101, the torque provided by such generator will be:

[0143] From the annexed figures it is apparent that the connection shaft 111 is arranged opposite with respect to the water inlet conduit 103.

[0144] Given that the generator has an efficiency r]G, the electric power thereby produced will be:

[0145] P el- P mech^G

[0146] Albeit this technical feature shall not be intended as limiting, in an embodiment the generator is configured to operate at a fixed rotation speed, e.g. at a nominal speed of 1000 rpm. Provided that no gearing ratio adapting device is provided between the generator and the reaction turbine 101 and the action turbine 102, the rotation speed of at least one between the reaction turbine 101 and / or the action turbine 102 may be the same rotation speed of the generator. Such rotation speed is regulated by an adaptation of the flow of water at the inlet of the turbine system.

[0147] A further embodiment studied by the Applicant is provided with a generator configured to rotate at a nominal speed of 1000 rpm, while by means of appropriate gearing ratio coupling, the reaction turbine rotates at 200 rpm while the action turbine rotates at 100 rpm.

[0148] In other embodiments, the generator may be a variable speed generator provided with speed controllers suitable to cause a regulation of the rotation speed thereof. Albeit this second configuration is more complex, it allows to set various pressures (that is various rotation speeds for the reaction turbine 101 and / or action turbine 102) with a same water flow rate at the inlet, and then allows to find the optimal rotation speed, and the maximum efficiency, for each water flow rate. Thus the speed controller is configured to keep the rotation speed of the generator within a predetermined range.

[0149] A speed adapter provided with appropriate gears may be operatively interposed between the generator and the reaction turbine 101 and / or action turbine 102.

[0150] The turbine assembly of the present disclosure may be configured to operate at a constant water mass flow rate and / or at a constant pressure.

[0151] Albeit several type of electric constructions for the generator may be chosen, in an embodiment the generator is a squirrel cage generator.

[0152] The generator receives a rotating torque momentum form an output shaft at which the reaction turbine 101 and the action turbine 102 are connected. GAI1P4W0

[0153] In a preferred, non-limiting, embodiment, the reaction turbine 101 and the action turbine 102 are connected to said output shaft by means of a transfer case coupling a rotating torque in use provided by a shaft of the reaction turbine 101 with a rotating torque in use provided by a shaft of the action turbine 102. Thus the generator's rotor is driven by the combined, simultaneous, effect of two different types of turbines, conjugating the beneficial effects of each of said turbines.

[0154] Applicant has conceived an embodiment which comprises a transfer case comprising a free wheel allowing a reciprocal free rotation between said shaft of said reaction turbine 101 and said shaft of said action turbine 102.

[0155] As it can be seen from figure 4, provided that each nozzle lOln has an inclination a with respect to the tangent of the circumference, the outreach dugof the nozzle is then: wherein RRis the radius of the reaction turbine 101 and a is the angle between the nozzle exit and the tangential direction in that point.

[0156] An angle 6 between the arm and the nozzle is thus independent from the outreach dugand from the angle a. Such angle 6 may be thus optimized by making more efficient the curve between the inner portion of the arm and the nozzle lOln, thus minimizing the energy losses.

[0157] The absolute speed of the water spray at the nozzle has a tangential component V2t [m / s] and a radial component V2r [m / s].

[0158] It is herewith reminded that V2R is the relative speed of the water flow with respect to the nozzle and is equivalent to: wherein Q. is the water flow rate in the turbine assembly, nuis the nozzles number and A2 [m2] is the size of the cross section of the nozzle lOln.

[0159] The actual angle of inclination of the water spray with respect to the tangent to the circumference is equal to:

[0160] The absolute speed v2 [m / s] of the water spray at the nozzle lOln can thus be written in the following form: v2Rsin a v2= sin a' GAI1P4W0

[0161] Given s [m] the distance traveled by the water spray from the nozzle lOln to a point P of impact on the water collection element 102e, said distance s may thus be written in the form:

[0162] The angle of the segment s is then:

[0163] The absolute angle a" of the water spray at the circumference having generic radius RA with respect to the tangent direction will be:

[0164] At the point P where the water sprayed from the nozzle lOln hits the water collection elements 102e, the tangential and radial components of the absolute speed V2 of the water are:

[0165] The components of the relative speed v2Aof the water sprayed from the nozzle lOln at point P, with respect to the water collection element 102e are:

[0166] The relative angle of inclination of the water sprayed from the nozzle lOln with respect to the tangent to the circumference is:

[0167] The relative speed V2A of the water sprayed from the nozzle lOln with respect to the water collection element can then be written in the following form:

[0168] The impact of the water sprayed from the nozzle lOln into the water collection element 102e is then optimal when the inclination p of the water collection element 102e at impact point P is equal to the relative angle of the spray a"A, that is to say when = a"A. Otherwise, the spray will be subdivided and a part thereof will exit from the outer part of the water collection element 102e and a further part thereof will exit from the inner part of the water collection element 102e.

[0169] The water that hits the water collection element 102e slides with respect thereto. There is thus a relative speed v3A [m / s] with respect to the water collection element 102e that is equal to v3j4= K ■ 1’2.4 GAI1P4W0 wherein k is a coefficient close to 1 that keeps into account the friction force along the path of the water sprayed on the water collection element 102e. For the purposes of the present disclosure, it may be considered that k=0,95.

[0170] The water outlet from the water collection element 102e takes place at circumferences having radiuses RAex and RAin, respectively for the outer and inner end of the water collection element 102e.

[0171] The relative inclination of the water collection element 102e of the water exiting from the water collection element 102e is equal to the inclination P2 and Pi of the end portion of the water collection element 102e.

[0172] The absolute angle ot2of outlet of the water from the water collection element 102e (outer end), with respect to the tangent to the circumference of radius RAex (outer end of the water collection element 102e) is equal to:

[0173] The absolute speed V3 of the water exiting the water collection element 102e (outer end) can be written in the following form:

[0174] The speed and angle of the water exiting the inner end of the water collection element 102e is calculated similarly to the water exiting the outer end of the water collection element 102e: wherein and v^Aare the absolute and relative speeds of the water exiting the inner end of the water collection element 102e. The angle op is the absolute inclination of the water exiting the inner end of the water collection element 102e.

[0175] For any hitting point of the water sprayed from the nozzle lOln to the water collection element 102e, identified by the circumference having radius RA passing by the impact point, the inlet of the water is optimal when the inclination p of the water collection element 102e with respect to the tangent to the circumference having radius RA at the impact point is equal to the relative inclination at the impact point P, that is to say when = a"A. GAI1P4W0

[0176] Actually the inlet is optimal also when the inclination p is slightly higher than a"A. Any energy loss that may result due to a non-optimal hitting of the water on the water collection element 102e is not considered.

[0177] The following two equations which are obtained from the balance of the momentum, quantitatively describe the separation of the flow that hits a planar face as a function of an angle of impact hereinafter defined:

[0178] The two equations are:

[0179] Q2and Q2are the water flow rates exiting the inner and outer end of the water collection element 102e.

[0180] Should be < a”A, it is considered that 0imp= 0.

[0181] The angle a"Adepends on water flow rate, rotation speed and impact point P. The angle p is a geometric characteristic of the water collection element 102e and depends only on the impact point P.

[0182] In figure 5 and in figure 6 a schematic view for analyzing the water collection element 102e profile is provided.

[0183] As it is apparent, each water collection elements 102e of the plurality of water collection elements 102e is concave. The concavity is directed radially inwards.

[0184] In each water collection element 102e a water receiving portion and a water discharge portion are identified.

[0185] The water receiving portion is configured to receive said water exiting said nozzle lOln and said water discharge portion is configured to let water flow away from said water collection element 102e.

[0186] When the water collection elements 102e rotate (in figure 4, in an anticlockwise direction), the water receiving portion is a front portion in the sense of rotation: it means that when an observer is arranged at a given fixed point with respect to the collection element 102e, and such collection element 102e moves towards the observer, the water receiving portion is the portion closer to observer. Consequently, the water discharge portion is the portion farther from the observer.

[0187] When considering the faces of the wall which is defined by each collection element 102e, it may be inferred that the water receiving portion has an inner face (actually hit by the water flow) and an outer face, opposed to the inner face. Also the water discharge portion has an inner face and an outer face. The two inner faces are on the same side of the water collection element 102e. It may thus be also GAI1P4W0 inferred that each water collection element 102e comprises an inner face and an outer face, opposed to the inner face.

[0188] Considering the direction of rotation of the water collection elements 102e (in figure 4, anticlockwise), the inner face is a face directed backwards in the sense of rotation of the action turbine 102 and the outer face is directed along the sense of rotation of the action turbine 102. The water always impacts on the same face of the water collection elements 102e, in particular the inner face.

[0189] In a preferred embodiment, the water receiving portion is a front portion in the sense of rotation of the action turbine 102. In contrast, the water discharge portion is a back portion in the sense of rotation of said action turbine 102.

[0190] The water discharge portion is configured to discharge water to a zone which is radially outer with respect to said action turbine 102 and / or below said action turbine 102. This allows to reduce the interference of the water flowing away from the water collection element 102e with other parts of the action turbine 102 and / or of the reaction turbine 101.

[0191] Preferably, albeit in a non-limiting extent, the water receiving portion defines a curved shape with a first radius, and the water discharge portion defines a curved shape with a second radius,

[0192] In one embodiment, the first radius is smaller than the second radius. Having a water receiving portion with a small radius allows to reduce the amount of water that after having impacted is sprayed away, and thus contributes to maximize the rotation thrust provided by the energy of the incoming water spray.

[0193] In another embodiment, the curved shape of the water receiving portion has a variable radius, and may have a radius which variates progressively. A further specific embodiment may involve a water receiving portion having a radius greater than the radius of the water discharge portion.

[0194] The impact point P is identified by the radius RA and by the angle 6. The impact point P is arranged at the water receiving portion. Thus: fx = RACOS 9 — RAln( y = RAsin 3

[0195] Angle p can be retrieved by the first derivative of the profile of the water collection element 102 and by the angle 6 as follows:

[0196] Where x and y belong to the coordinate system (Fig. 5) centered in the inner point of the water collection element, with x being radially directed (towards the outside of the turbine) and y being tangentially directed (against the rotation of the action turbine). GAI1P4W0

[0197] Since the reaction turbine 101 and the action turbine 102 are counter-rotating, the actual point of impact P of the water sprayed from the nozzle lOln to the water collection element 102e is timevariant. Experimental data shown that the efficiency of the turbine reaches a maximum when the relative inclination angle with respect to the water collection element 102e a"Ais equal to the inclination Pi of the inner side of the water collection element 102e. The inner end of the water collection element 102e is a preferred point for determining the efficiency of the turbine system.

[0198] Figure 7 shows that there are two ranges of angles of incidence (a ,min- ar, max) that locally maximize the efficiency of the turbine system: [30 - 40]°, more in particular [32 - 38]°, or [42 - 58]°, more in particular [45 - 55]°. The second range is related to the highest possible efficiency.

[0199] The graph of figure 7 further shows that the width of the ranges is substantially independent of the flow rate of water flowing from the nozzles lOln; in contrast, for a given range, a variation of the flow rate of water determines a variation of the overall efficiency of the turbine system.

[0200] The graph of figure 7 shows three curves relating to three different water flow rates (Q. [l / s] ), namely Q= 4.55 ± 0.05 l / s, Q=3.77 ± 0.06 l / s and Q= 5,42 ± 0,07 l / s. It has been noted that while the efficiency curve when the water flow rate Q. is equal to 4.55 ± 0.05 l / s may be considered substantially equivalent to the efficiency curve when the water flow rate Q. is equal to 3.77 ± 0.06 l / s, when the water flow rate Q. is 5,42 ± 0,07 l / s the graph shows that the overall efficiency decreases, even though the shape of the curve is still similar to the shape of the curve when the water flow rate Q. is 4.55 ± 0.05 l / s or 3.77 ± 0.06 l / s. Thus, the turbine here disclosed is provided with a predetermined water flow rate that defines a substantial threshold of flow rates, above which the overall efficiency decreases. More specifically, it may be considered that in a subrange of an overall range of angles of incidence (a ,min - a , ax), when the water flow rate exceeds the threshold, the efficiency is lower than the efficiency when the water flow rate is below said threshold for the same subrange. In particular the graph of figure 7 shows that in the entire range of angles of incidence (ar, min - ar, max) between 28° and 64°, when the water flow rate exceeds the threshold, the efficiency is lower than the efficiency when the water flow rate is below said threshold for the same entire range. In the graph of figure 7, the first peak is related to ar while the second peak is related to the ratio up / ug.

[0201] The turbine system of the present disclosure can be in particular characterized by an efficiency that, given a predetermined angle of incidence, increases with the increase of the water flow rate [l / s] at the turbine inlet.

[0202] Each nozzle lOln has a relative water flow rate QA (with respect to the water collection element) which is given by: GAI1P4W0 wherein D2 [m] is the diameter of the water spray (considered equivalent to the diameter of the nozzle lOln), the relative speed of the water spray with respect to the water collection element 102e when hitting the water collection element 102e.

[0203] Let's consider figure 8. The width D3 of the water spray at the exiting section of the water collection element 102e is given by: wherein ha is the extension of the part of the water collection element 102e which is occupied by the water spray.

[0204] In a preferred embodiment, a specific portion of the water collection element 102e is fully invested by the water spray. Alternative embodiments studied by the Applicant show that the water flowing outside each nozzle of said plurality of nozzles lOln defines an overall cross section substantially equal to at least 50%, preferably equal to at least 60%, more preferably substantially equal to at least 75% of an overall surface of each water collection element 102e.

[0205] In other embodiments conceived by the Applicant, the water flowing outside each nozzle of the plurality of nozzles lOln defines an overall cross section which is below 50%, or below 40%, or below 30% of an overall surface of each water collection element 102e of the plurality of water collection elements 102e.

[0206] At the inner side of the water collection element 102e it results that: tsis the traveling time of the water exiting the nozzle lOln and reaching the impact point P.

[0207] During the aforementioned traveling time, the nozzle lOln is subjected to a rotation of 0u^degrees, wherein tsvis the time span requested by the water to exit the water collection element 102e, and to reach the circumference having radius RRex:

[0208] The term

[0209] L = AP is the curved path of the water collection element 102e, and starts from the impact point P up to the inner end A.

[0210] The radius RRexis: GAI1P4W0 r is the thickness of the conduit in correspondence of the nozzle lOln.

[0211] Operation of the turbine assembly

[0212] During the time span tsvthe relative angle traveled by the reactive turbine 101 and by the active turbine

[0213] 102 is:

[0214] The condition at the output is verified in case the residual angle between the position of the water spray exiting the outer edge of the water collection element 102e and the end point of the subsequent nozzle lOln will be positive:

[0215] The active toque MR generated by the reaction turbine 101 is calculated by means of the momentum of the thrust caused by the spray on the nozzle lOln, and is

[0216] Considering V2At positive, the active torque MA generated by the action turbine 102 is positive and is calculated similarly as a Pelton turbine:

[0217] In contrast when V2At is negative (the absolute speed of the water collection element 102e is greater to or equal to the absolute speed of the spray), the active torque MA generated by the action turbine 101 is negative or zero, i.e. the water collection element 102e finds a dragging force crossing the spray, and then the action turbine 102 generates a resistant torque on the reaction rotor.

[0218] In an embodiment, the braking torque Mf that is generated by the frictional force of the bearings 107 and gears may be assumed to be linearly dependent to the rotation speed of the reaction turbine 101.

[0219] Mf = Mf04- f ■ MR

[0220] The water spray exiting the inner end of the water collection element 102e can hit an arm of the reaction turbine 101 that comes progressively closer due to the counter-rotation. Approximately, the force Ff that is exerted by the water blade on a single arm of the reaction turbine 101 can be estimated with the following equation: GAI1P4W0 wherein> v^) is the relative speed of the water spray impacting on the rear part of the nozzle lOln, Divis the average (outer) diameter of the section of arm hit by the spray.

[0221] The term is the projection of the cross section of the zone of the arm hit by the spray.

[0222] D3is calculated by continuity from the water flow rate (?2exiting from the inner end of the water collection element 102e.

[0223] The braking torque is therefore:

[0224] The term RRyis the distance, from the center of the turbine, of the impact point of the spray on the rear side of the nozzle lOln.

[0225] The volumetric efficiency / jTO / is given by the following equation:

[0226] Where Qpis the flowrate effectively hitting the water collection elements.

[0227] Figure 9 and figure 10 show the mechanical efficiency as a function of the ratio between the absolute speeds of the water collection element / water jet.

[0228] As it can be seen, after a certain value of rotation speed, the volumetric efficiency rjvoiof the turbine decreases linearly with the increase of the rotation speed, since the radial component of the spray exiting from the nozzle lOln increases and passes through the spaces between the water collection element 102e.

[0229] The water turbine system is in particular conceived to feed a energy distribution network, realizing said load.

[0230] It is in particular observed that the voltage present on the load is characterized by:

[0231] - a specific waveform, commonly sinusoidal in the traditional electric energy distribution networks;

[0232] - a specific frequency, e.g. 50 Hz or 60 Hz;

[0233] - a specific voltage value, e.g. 150kV RMS;

[0234] - a specific instant phase angle,

[0235] - a specific phase sequence, on the outlet lines exiting from the energy outlet of the generator.

[0236] Such parameters shall be matched by the system of the present disclosure in order to allow an effective and safe energy production.

[0237] Applicant notes that matching a sinusoidal waveform is quite common as traditional generators produce alternate voltages with sinusoidal waveforms due to their intrinsic construction. GAI1P4W0

[0238] The use of a governor will help to keep good synchronization to the electric energy distribution network even in case the volume of water instantly feeding the turbine may variate up to a certain extent; the governor thus allows the water turbine system 100 of the present disclosure be selfcontrolling; there is no need to keep a constant surveillance of qualified operators to keep appropriate functioning and energy production.

[0239] A power switch is provided at the outlet of the generator.

[0240] When the turbine is not operative, the power switch is kept in the open configuration in order to prevent the herewith disclosed system absorb current from the electric distribution network.

[0241] During the startup of the turbine, when the power unit, through the governor, detects that the voltage, frequency, phase sequence and phase angle of the voltage upstream the power switch match those present on the load, i.e. match those present downstream the power switch, the power switch can be switched from the open configuration to the closed configuration thus determining the actual connection with the network.

[0242] More in particular, the water turbine assembly of the present disclosure is configured to carry out a synchronization phase with the load.

[0243] The turbine system, through the action of the power unit, is configured to:

[0244] - automatically and electronically detect at least one, preferably all, among a voltage, frequency, phase sequence, phase angle of the voltage on said load;

[0245] - adapt a rotation speed of said water turbine and / or of said generator, in such a way to make the at least one, preferably all, among a voltage, frequency, phase sequence, phase angle of the voltage of the electric energy to be fed to said load, in particular to said electric energy distribution network, match the at least one, preferably all, among a voltage, frequency, phase sequence, phase angle of the voltage on said load.

[0246] In general terms it may be inferred that the water turbine system is configured and destined to cope with variations of the load, in particular with variations of a resistive and / or reactive impedance of said load. The water turbine system according to the present disclosure is thus configured to adapt automatically any of its operative parameters, e.g. the rotation speed of the reactive turbine 101 and / or of the active turbine 102, according to a variation of impedance of the load represented by the power distribution network connected to the load.

[0247] The adaptation phase above described is carried out while still electronically and automatically detecting said at least one, preferably all, among said voltage, frequency, phase sequence, phase angle of the voltage of said load, in a recursive control up to a moment when at least one, preferably all, among a voltage, frequency, phase sequence, phase angle of the voltage of the electric energy to be fed to said load lie inside or go inside a safety range of closeness to the at least one, preferably all, GAI1P4W0 among a voltage, frequency, phase sequence, phase angle of the voltage on said load. At this moment the governor locks the system, which is kept synchronized with the network.

[0248] Preferably, albeit in a non-limiting extent, the power unit can be configured to disconnect the system from the load in case of emergency. This technical feature prevents the risk of causing damages to the load; this technical feature is particularly important in case the load is an electric distribution network, as any electrical issue in the herewith disclosed system may reflect on a wide area and on a relevant plurality of users and / or generators.

[0249] An emergency condition may be a short circuit in the power unit, in particular occurring upstream the power switch, or may be a short circuit in the generator, or a sudden lowering of the rotation speed of the turbine, or may be a sudden blockage of the turbine.

[0250] The power unit may be provided with sensors capable of detecting immediately any emergency condition and immediately cause a switching from the closed configuration to the open configuration for the power switch. Should an emergency condition take place, it is important to switch the configuration of the power switch substantially immediately and preferably within a maximum time delay of some seconds.

[0251] It is further noted that a preferred embodiment of the water turbine system 100 object of the present disclosure is adaptable in the number of nozzles lOln and / or water collection elements 102e. This technical feature further increases the overall range of operative conditions at which the water turbine system 100 can operate with maximized efficiency. In general, the numerosity of the plurality of water collection elements 102e is a predetermined multiple of the numerosity of the plurality of nozzles lOln, and preferably is a predefined multiple of the numerosity of the nozzles lOln.

[0252] More in detail, at least a number of said nozzles lOln and / or an opened or closed configuration thereof, and / or a number of said water collection elements 102e, and / or a relative position and / or orientation between said nozzles lOln and / or water collection elements 102e, is adaptable.

[0253] Preferably the adaptation is an operative adaptation.

[0254] A preferred embodiment of the turbine is provided with a water collection reservoir arranged at a bottom portion and / or below said reaction turbine 101 and said action turbine 102.

[0255] The water collection reservoir is configured to house at least part of the water that exits from the plurality of water collection elements 102e that realize the action rotor 102.

[0256] The water collection reservoir is provided with an outlet port, a bottom wall and a lateral wall. Preferably said lateral wall is substantially circular.

[0257] Preferably, said outlet port is arranged in correspondence of the lateral wall.

[0258] The water collection reservoir is centered on the rotation axis of the reaction rotor 101 and / or of the action rotor 102, and preferably houses at least a part of the shaft of said reaction rotor 101 and / or of said action rotor 102. This provides a particular compactness to the turbine system. GAI1P4W0

[0259] Applicant further notices that in a preferred, non-limiting, embodiment, the water turbine system of the present disclosure is adaptable, preferably operatively adaptable, to a water flow rate at said water inlet conduit 103.

[0260] Particular, non-limiting, embodiments of the turbine system are provided with a plurality of nozzles lOln removably installed and / or operatively installed in a removable way. Alternatively, at least a part of said plurality of nozzles lOln is at least partially selectively closeable in such a way to adapt a flow rate of the plurality of nozzles lOln and / or of said reaction turbine 101.

[0261] Alternatively, or in combination, said plurality of water collection elements 102e is removably installed and / or operatively installed in a removable way.

[0262] The turbine system of the present disclosure may comprise a case that helps a rapid installation at a predetermined place, and that is suitable to make the turbine system of the present disclosure an actual plug-and-play turbine.

[0263] The case houses the turbine assembly realized by the reaction turbine 101 and by the action turbine 102 and preferably also houses the generator. These elements are housed in a substantially closed structure which allows to isolate the turbine assembly and the generator from the outer environment. In particular, the case is configured to be laid on a ground or a pre-existing building structure, e.g. made in concrete.

[0264] The case comprises a supporting structure for the turbine assembly and the generator. The supporting structure may comprise beams and traverses that withstand the overall weight of the turbine assembly and of the generator, included the water that in use is contained within the turbine assembly.

[0265] The case may be a container assuming a substantially boxed shape which is very effective to be transported by means of trucks and / or by means of aeronaval transport vehicles.

[0266] Particular embodiments of the case may be in the form of standard-sized intermodal containers, which of course clearly facilitate the loading and transport on standard-sized vehicles. The case may be provided with hooks allowing hoisting by means of cranes and / or helicopters.

[0267] In a preferred embodiment, the case is provided with an access opening preferably realized in form of a single or double swinging door; the access opening allows an operator access at least the turbine assembly and the generator to provide e.g. periodic servicing. In an embodiment, the case 105 is sized in such a way to allow an operator enter and walk in the confined environment thereby defined while being in a substantial erected position.

[0268] A particular, non-limiting, embodiment of the case is in the form of an intermodal container, preferably according to ISO standards. Other forms of substantially boxed-shape cases are possible.

[0269] This technical feature allows easiness of transportation as traditional industrial intermodal transport vehicles are mechanically structured to house and sustain ISO standard intermodal containers. GAI1P4W0

[0270] It is considered that the object of the present disclosure is not limited to the embodiments shown in the annexed figures. Therefore, the reference numbers and signs provided in the claims are provided for the sole scope of increasing the intelligibility thereof, and shall not be considered as limiting.

[0271] It is finally clear that to the object of the present disclosure additions and adaptations may be provided without for this departing from the scope of protection provided by the annexed claims.

Claims

1. GAI1P4W0Claims1. A water turbine system, comprising:- a reaction turbine (101) comprising a plurality of nozzles (lOln),- an action turbine (102) comprising a plurality of water collection elements (102e) and configured to be fed by said reaction turbine (101); wherein the spatial configuration of said reaction turbine (101) and of said action turbine (102) is such that water exiting each nozzle (lOln) of said plurality of nozzles (lOln) hits at least a first respective water collection element (102e) of said plurality of water collection elements (102e) with a predetermined angle of incidence (a ) and determines:- a rotation of said reaction turbine (101) with a reaction turbine speed (o>R), and- a rotation of said action turbine (102) with an action turbine speed (o> A); a geometry of said reaction turbine (101) and of said action turbine (102) being configured to keep at least said angle of incidence (a ) and / or at least a ratio (r) between said reaction turbine speed ( >R) and said action turbine speed (o> A), or between a speed (<jjARALn) °f the action turbine (102) and a speed (V2) of the water exiting from at least one of said plurality of nozzles (lOln), within at least one respective predetermined range of angles of incidence (ar, min - ar, max) and / or of range of ratios (rmin - rmax) maximizing an efficiency of the turbine system.

2. The water turbine system according to claim 1, wherein the reaction turbine (101) and the action turbine (102) are co-axial, and wherein said water exiting each nozzle (lOln) of said plurality of nozzles (lOln) determines a rotation of said reaction turbine (101) in a first rotation direction and of said action turbine (102) in a second rotation direction opposed to said first rotation direction.

3. The water turbine system according to claim 1 or 2, wherein said reaction turbine (101) and said action turbine (102) are substantially co-planar.

4. The water turbine system according to one or more of the preceding claims, wherein at least part of the nozzles (lOln) of said plurality of nozzles (lOln) in use spray water along a direction which is parallel to, and / or lies on, a plane on which the reaction turbine (101) and / or the action turbine (102) in use rotate and / or wherein at least a part of the nozzles (lOln) of said plurality of nozzles (lOln) in use spray water along a direction which is inclined with respect to, and / or does not lie on, a plane on which the reaction turbine (101) and / or the action turbine (102) in use rotate.GAI1P4W05. The water turbine system according to one or more of the preceding claims, wherein said reaction turbine (101) and said action turbine (102) are configured to rotate on a plane which is substantially horizontal or substantially inclined with respect to a horizontal plane and which is optionally a vertical plane.

6. The water turbine system according to one or more of the preceding claims, comprising a water inlet conduit (103) feeding said reaction turbine (101); said water inlet conduit (103) being arranged at a bottom portion of said reaction turbine (101) and / or feeding said reaction turbine (101) with water flowing upwardly, in particular with water flowing along a substantially vertical direction, or said water inlet conduit (103) being arranged at a lateral portion of said reaction turbine (101) and / or feeding said reaction turbine (101) with water flowing from a left side or a right side direction, in particular with water flowing along a substantially horizontal direction.

7. The water turbine system according to claim 6, wherein said water inlet conduit (103) is at least partially centered on a rotation axis of said reaction turbine (101) and of said action turbine (102).

8. The water turbine system according to one or more of the preceding claims comprising an output shaft, the reaction turbine (101) and the action turbine (102) being connected to said output shaft, preferably being connected to said output shaft by means of a transfer case coupling a rotating torque in use provided by a shaft of said reaction turbine (101) with a rotating torque in use provided by a shaft of said action turbine (102), optionally the transfer case comprising a free wheel allowing a reciprocal free rotation between said shaft of said reaction turbine (101) and said shaft of said action turbine (102).

9. The water turbine system according to one or more of the preceding claims, wherein said ratio (r) between the speed (6L>^ / ?^m)of the action turbine (102)and the speed (V2) of the water exiting from at least one of said plurality of nozzles (lOln) is [0,2 - 0,3] or [0,4 - 0,6] or wherein the range of ratios (rmin - rmax) between said reaction turbine speed (a)R) and said action turbine speed (a) A) is between [0,2 - 1] or between [0,3 - 0,9], optionally wherein said range of ratios is independent of a flow rate of water flowing from said plurality of nozzles (lOln).

10. The water turbine system according to one or more of the preceding claims, wherein said range of angles of incidence (a ,min- ar, max) is [30 - 40]°, optionally [32 - 38]°, or is [42 - 58]°, optionally [45 -GAI1P4W055]°, optionally wherein said range of ratios is independent of the flow rate of water flowing from said plurality of nozzles (lOln).

11. The water turbine system according to one or more of the preceding claims when depending on claim 6, wherein at a given angle of incidence, the efficiency increases with a water flow rate at said water inlet conduit (103) or being characterized by a predetermined flow rate above which the efficiency decreases, preferably independently of the given angle of incidence, with respect to an efficiency at a same angle of incidence and below said predetermined flow rate.

12. The water turbine system according to one or more of the preceding claims, wherein said each water collection element (102e) of said plurality of water collection elements (102e) is provided with a collection surface concave in a radially inward direction.

13. The water turbine system according to claim 12, wherein each water collection element (102e) of said plurality of water collection elements (102e) comprises a water receiving portion and a water discharge portion, wherein the water receiving portion is configured to receive said water exiting said nozzle (lOln) and wherein said water discharge portion is configured to let water flow away from said water collection element (102e), wherein the water receiving portion is a front portion in the sense of rotation of said action turbine (102) and wherein the water discharge portion is a back portion in the sense of rotation of said action turbine (102); preferably wherein the water collection element (102e), optionally said water receiving portion and said water discharge portion, comprises an inner face, in use hit by the water flow, and an outer face, and wherein said inner face is directed backwards in the sense of rotation of the action turbine (102) and the outer face is directed along the sense of rotation of the action turbine (102), and wherein said water discharge portion is configured to discharge water to a zone which is radially outer with respect to said action turbine (102) and / or below said action turbine (102).

14. The water turbine system according to claim 13, wherein the water receiving portion defines a curved shape with a first radius, wherein the water discharge portion defines a curved shape with a second radius, the first radius being smaller than the second radius.GAI1P4W015. The water turbine system according to one or more of the preceding claims, wherein each nozzle of said plurality of nozzles (lOln) has a substantially circular cross section.

16. The water turbine system according to one or more of the preceding claims, wherein the water flowing outside each nozzle of said plurality of nozzles (lOln) defines an overall cross section substantially equal to at least 50%, preferably equal to at least 60%, more preferably substantially equal to at least 75% of an overall surface of each water collection element (102e) of said plurality of water collection elements (102e) or wherein the water flowing outside each nozzle of said plurality of nozzles (lOln) defines an overall cross section which is below 50%, or below 40%, or below 30% of an overall surface of each water collection element (102e) of said plurality of water collection elements (102e).

17. The water turbine system according to one or more of the preceding claims, wherein the reaction turbine (101) comprises:- a central portion (105);- a plurality of hollow arms (110) having a first end connected to said central portion (105) and a second end opposite to the first end realizing said nozzle (lOln); and wherein each hollow arm comprises a first portion (107), in particular a radially inner portion, directed along a radial direction with respect to said central portion (105), and comprises a second portion (108), in particular a radially outer portion, directed along a direction inclined with respect to said radial direction.

18. The water turbine system according to one or more of the preceding claims, wherein a numerosity of said plurality of water collection elements (102e) and a numerosity of said plurality of nozzles (lOln) are mutually correlated, preferably wherein the numerosity of said plurality of water collection elements (102e) is a predefined multiple of the numerosity of said plurality of nozzles (lOln).

19. The water turbine system according to one or more of the preceding claims, comprising or connected to an electric generator, said electric generator being connected to at least one between said reaction turbine (101) and / or said action turbine (102), preferably simultaneously to said reaction turbine (101) and said action turbine (102), by means of a connection shaft (111), said generator being configured to produce electric energy to feed to a load, preferably wherein said load is an energy distribution network.GAI1P4W020. The water turbine system according to claim 19, being configured and destined to cope with variations of said load, in particular with variations of a resistive and / or reactive impedance of said load.

21. The water turbine system according to claim 19 or to claim 20, wherein said generator is configured to rotate at a constant generator speed, or is configured to rotate at a variable generator speed; optionally the water turbine system comprising a generator speed regulator, configured to keep said generator speed within a predetermined range; preferably said generator being a three-phase generator and / or being a squirrel cage generator.

22. The water turbine system according to one or more of claims 19-21, wherein said generator is opposed with respect to said water inlet conduit (103).

23. The water turbine system according to claim 21 or claim 22, comprising a power unit configured to electronically detect at least one, preferably all, among a voltage, frequency, phase sequence, phase angle of the voltage on said load and to cause an adaptation of a rotation speed of said water turbine and / or of said generator, in such a way to make the at least one, preferably all, among a voltage, frequency, phase sequence, phase angle of the voltage of the electric energy to feed to said load, in particular to said electric energy distribution network, match the at least one, preferably all, among a voltage, frequency, phase sequence, phase angle of the voltage on said load.

24. The water turbine system according to claim 23, wherein the power unit comprises a power switch connected at an outlet of said generator; said power unit being configured to:- keep said power switch in an open configuration, or to cause an automatic switching of said power switch, when at least one, preferably all, among a voltage, frequency, phase sequence, phase angle of the voltage of the electric energy to feed to said load lie outside or go outside a safety range of closeness to the at least one, preferably all, among a voltage, frequency, phase sequence, phase angle of the voltage on said load, or to keep said power switch during a synchronization phase, and- switch to a closed configuration, or to keep said configuration, of said power switch, when at least one, preferably all, among a voltage, frequency, phase sequence, phase angle of the voltage of the electric energy to be fed to said load lie inside or go inside a safety range of closeness to the at least one, preferably all, among a voltage, frequency, phase sequence, phase angle of the voltage on said load, or after said synchronization phase.GAI1P4W025. The water turbine system according to one or more of the preceding claims, wherein at least a number of said nozzles (lOln) and / or an opened or closed configuration thereof, and / or a number of said water collection elements (102e), and / or a relative position and / or orientation between said nozzles (lOln) and / or water collection elements (102e), is adaptable, preferably operatively adaptable, to a water flow rate at said water inlet conduit (103), preferably wherein said plurality of nozzles (lOln) is removably installed and / or operatively installed in a removable way, and / or is at least partially selectively closeable in such a way to adapt a flow rate of the plurality of nozzles (lOln) and / or of said reaction turbine (101) and / or wherein said plurality of water collection elements (102e) is removably installed and / or operatively installed in a removable way.

26. The water turbine system according to one or more of the preceding claims, comprising a water collection reservoir arranged at a bottom portion and / or below said reaction turbine (101) and said action turbine (102); the water collection reservoir being configured to house at least part of the water that exits from the plurality of water collection elements (102e).

27. The water turbine system according to claim 26, wherein the water collection reservoir is provided with an outlet port, a bottom wall and a lateral wall and preferably wherein said lateral wall is substantially circular; said outlet port being arranged in correspondence of the lateral wall.

28. The water turbine system according to claim 26 or to claim 27, wherein the water collection reservoir is centered on the rotation axis of the reaction rotor (101) and / or of the action rotor (102), and preferably houses at least a part of the shaft of said reaction rotor (101) and / or of said action rotor (102).

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