EP0607357B1 - Method of driving a turbine in rotation by means of a jet device - Google Patents

Abstract

PCT No. PCT/FR92/00957 Sec. 371 Date Apr. 7, 1994 Sec. 102(e) Date Apr. 7, 1994 PCT Filed Oct. 9, 1992 PCT Pub. No. WO93/07361 PCT Pub. Date Apr. 15, 1993A turbine device and a method of driving the turbine device are disclosed. The turbine device includes an admission channel, a turbine, and an injection channel. The turbine device may also include a regulator. The turbine is driven by injecting a primary fluid into the admission channel at a given velocity and simultaneously causing a secondary fluid to flow into the admission channel at a lower velocity. The primary fluid and the secondary fluid form a mixture in the admission channel, which flows toward the turbine. The velocity of the mixture is less than that of the primary fluid, while the mass flow of the mixture is approximately equal to the sum of the mass flows of the primary and secondary fluids. The regulator compares the rotational speed of the turbine to a target speed and regulates parameters associated with the turbine device if the rotational speed of the turbine and the target speed differ by more than a predetermined amount.

Description

The present invention relates to a method for rotating a turbine and a corresponding turbine device.

Turbines have been known for a long time and are essentially constituted by a hub carrying blades, driven in rotation by a fluid (gas, liquid) passing through it.

In known manner, driving a turbine with a fluid makes it possible to transfer the energy of the fluid to the axis of rotation of the turbine. For example, the rotation of this axis is used to drive an alternator to produce electric current, or to drive various tools (drilling, sawing ...).

• d'ondes de choc,
• de faisceaux de détente ou de compression apparaissant sur les divers composants du dispositif.

To date, the problems of known devices reside in the high flow velocities necessary for obtaining the highest possible powers. However, these high flow rates lead to strong disturbances; for example when the fluid is a gas, there is creation:

• shock waves,
• expansion or compression beams appearing on the various components of the device.

• les composants de ces dispositifs doivent présenter des formes particulières, précises, optimum (ce qui implique un domaine d'utilisation limité, voire très limité),
• lesdits composants doivent résister mécaniquement aux efforts induits par les phénomènes vibratoires accompagnant ces perturbations,
• lesdites perturbations engendrent des phénomènes acoustiques souvent très violents.

The consequences of such disturbances are inter alia that:

• the components of these devices must have specific, precise, optimum shapes (which implies a limited or even very limited area of use),
• the said components must mechanically resist the forces induced by the vibrational phenomena accompanying these disturbances,
• said disturbances generate acoustic phenomena which are often very violent.

• les systèmes thermiques propulsifs à trompes qui génèrent une force par la création d'une différence de pression entre l'amont et l'aval du système. Le dispositif décrit dans le brevet FR 522.163 utilise ainsi une partie de l'énergie d'un écoulement gazeux se caractérisant principalement par des termes de vitesses, pour comprimer à l'aide d'une turbine, les combustibles et comburants nécessaires au fonctionnement du système,
• les systèmes thermiques tels que celui décrit dans le brevet GB 1.140.543 dont la température de la source chaude est trop élevée pour être utilisée directement, et qui sont conçus pour permettre un effet de refroidissement par dilution.

By using the Venturi effect or trunk effect, it is possible to entrain a secondary fluid by ejecting a primary fluid through a nozzle. Many devices implement this effect, and in particular:

• thermal propellant systems with horns which generate a force by creating a pressure difference between the upstream and downstream of the system. The device described in patent FR 522,163 thus uses part of the energy of a gas flow characterized mainly by terms of speeds, to compress using a turbine, the fuels and oxidizers necessary for the operation of the system ,
• thermal systems such as that described in patent GB 1,140,543, the temperature of the hot source of which is too high to be used directly, and which are designed to allow a cooling effect by dilution.

It should be added that the devices described in these two documents include:
an upstream fluid supply channel, a turbine, a downstream channel, means for injecting a primary fluid, means for admitting a secondary fluid and means for mixing the primary and secondary fluids.

Another aspect limiting the use of prior turbine devices lies in the high, or even very high, speeds of rotation of these devices.

The present invention aims to overcome all of these drawbacks and in particular to create a turbine whose nominal operating point is not associated with a transonic flow speed, in order to avoid all the problems linked to the disturbances induced by such flow.

It will be recalled that an operating point is characterized by a value torque (rotation speed, power) or (rotation speed, torque). In the present description, a nominal operating point is an operating point corresponding to a maximum power. The operating point corresponding to maximum torque will be called the operating point at nominal torque.

One of the aims of the invention is to obtain powers comparable to those obtained on conventional turbines, but with flow velocities compatible with undisturbed or little disturbed flows.

• admettre un fluide secondaire Fs dans le canal d'amenée de fluide, ledit canal d'amenée présentant une section d'entrée apte à générer un écoulement de fluide secondaire à fort débit masse Dms, avec une vitesse Vs et une pression Ps,
• injecter simultanément un fluide primaire Fp, présentant une pression Pp, une vitesse Vp très supérieures à celles du fluide secondaire, et un débit masse dmp déterminés, de façon à obtenir, dans le canal d'amenée de fluide, un mélange homogène présentant un fort débit masse égal à la somme (Dms + Dmp) des fluides primaire et secondaire, et une vitesse d'écoulement vers la turbine faible relativement à la vitesse du fluide primaire Fp,
• entraîner en rotation la turbine par le passage du mélange de fluide sur des aubes de cette turbine et
• éjecter le mélange de fluide au moyen du canal d'éjection de fluide dont la section de sortie est conçue pour adapter le niveau de pression en sortie sensiblement à celui du fluide présent aux alentours de la section d'éjection.

To this end, the present invention relates to a method for driving a turbine in rotation, said turbine being connected to an upstream fluid supply channel to a downstream ejection channel, said method comprising the steps of:

• admitting a secondary fluid Fs into the fluid supply channel, said supply channel having an inlet section capable of generating a flow of secondary fluid at high mass flow rate Dms, with a speed Vs and a pressure Ps,
• simultaneously inject a primary fluid Fp, having a pressure Pp, a speed Vp much higher than that of the secondary fluid, and a determined mass flow dmp, so as to obtain, in the fluid supply channel, a homogeneous mixture having a high mass flow rate equal to the sum (Dms + Dmp) of the primary and secondary fluids, and a low flow speed towards the turbine relative to the speed of the primary fluid Fp,
• drive the turbine in rotation by the passage of the fluid mixture over the blades of this turbine and
• ejecting the fluid mixture by means of the fluid ejection channel, the outlet section of which is designed to adapt the pressure level at the outlet substantially to that of the fluid present around the ejection section.

Thus, the fact of injecting a primary fluid at higher pressure and speed than the secondary fluid drives the latter towards the turbine. This effect is known as the Venturi effect. However, this effect is used in the present invention as an energy transformer and speed reducer. Indeed, the Venturi effect, in this case, transforms the energy of the primary fluid injected by a nozzle with low mass flow and high speed and pressure, into the energy of a fluid (resulting from the mixing of said primary fluid with the secondary fluid sucked in by Venturi effect) characterized by a high mass flow and a low flow speed.

However, in known manner, the power available on the axis of rotation of the turbine is:
P = C.ω. where C is the torque delivered and ω the speed of rotation of the turbine. The torque is expressed by: C = Fd where F is the overall radial force resulting from the flow of the fluid in the inter-blade channels of the turbine, and where d is the distance from the point of application of this force to l axis of the turbine.

où :

• Dmm est le débit masse du fluide traversant la turbine (c'est-à-dire du mélange du fluide),
• βe est l'angle d'attaque des aubes de la turbine,
• βs est l'angle de bord de fuite des aubes de la turbine,
• We est le module de la vitesse relative (repère tournant avec la turbine) d'entrée du fluide dans la turbine,
• Ws est le module de la vitesse relative de sortie du fluide dans la turbine.

In addition, if we take the case of a gas flow, as a first approximation, the force F is expressed by the following formula: $$\text{F = Dmm (We sin (βe) - Ws sin (βs))}$$

or :

• Dmm is the mass flow rate of the fluid passing through the turbine (i.e. of the mixture of the fluid),
• βe is the angle of attack of the turbine blades,
• βs is the trailing edge angle of the turbine blades,
• We is the modulus of the relative speed (reference mark rotating with the turbine) of fluid entering the turbine,
• Ws is the modulus of the relative speed of exit of the fluid in the turbine.

For a given nominal operating point, therefore characterized by a given power and a rotational speed (ω), a torque (C) and therefore a force (F) are sought. This force F is obtained by producing a high mass flow Dmm equal to the sum of the mass flows dmp + Dms, while having fluid flow speeds We and Ws sufficiently low to be compatible with a flow that is not very disturbed.

In addition, the method according to the invention makes it possible, by acting continuously on the pressure and / or the speed of the primary fluid and / or on any other dimensional or functional parameter of the turbine device, to be able to adapt the nominal operating point of the device at setpoint operating point.

The actual speed is measured continuously and then compared to a set speed. This setpoint speed is determined for a given application. For example, if the turbine drives a milling tool, this speed can be 36,000 rpm.

Following this comparison, one or more dimensional or functional parameters are continuously modified so that the measured speed of rotation is equal to the reference speed of rotation.

Advantageously, to modify the dimensional parameters, the inlet sections of the secondary fluid, injection of the primary fluid and outlet of the fluid ejection channel, are continuously modified so as to equal, as much as possible, the setpoint operating point and nominal operating point.

Advantageously, in order to modify the functional parameters, in addition to the variation in pressure of the primary fluid, the injection of the primary fluid can be done according to a helical trajectory inducing self-limitation and self-adaptation of the operating regime of the turbine. Such an injection mode is said to be helical.

Likewise, advantageously, the injection of the primary fluid takes place in zones close to the walls of said supply channel. Such an injection mode is said to be parietal.

• à l'intérieur d'un corps présentant globalement une symétrie de révolution, une turbine, un canal amont d'amenée de fluide vers la turbine, et un canal aval d'éjection de fluide,
• des moyens d'injection dans le canal d'amenée de fluide, d'un fluide primaire Fp présentant une pression, une vitesse et un débit masse dmp déterminés,
• des moyens d'admission dans le canal d'amenée de fluide, d'un fluide secondaire Fs présentant un débit masse Dms,
• le canal d'amenée de fluide présentant une section d'entrée apte à générer un écoulement de fluide secondaire à fort débit masse Dms, avec une vitesse vs et une pression Ps,
• les moyens d'injection étant adaptés pour délivrer un fluide primaire Fp présentant une pression et une vitesse très supérieures à celles du fluide secondaire, et sont disposés de façon à permettre l'obtention, à l'intérieur du canal d'amenée de fluide, d'un mélange homogène présentant un fort débit masse égal à la somme (Dms + Dmp) des fluides primaire et secondaire, et une vitesse d'écoulement vers la turbine faible relativement à la vitesse du fluide primaire Fp,
• le canal d'éjection présentant une section de sortie apte à adapter le niveau de pression en sortie sensiblement à celui du fluide présent aux alentours de la section d'éjection.

The present invention also relates to a turbine device implementing the method described above, said device comprising:

• inside a body having generally a symmetry of revolution, a turbine, an upstream channel for supplying fluid to the turbine, and a downstream channel for ejecting fluid,
• means for injecting into the fluid supply channel, a primary fluid Fp having a determined pressure, speed and mass flow rate dmp,
• means for admitting a secondary fluid Fs having a mass flow rate Dms into the fluid supply channel,
• the fluid supply channel having an inlet section capable of generating a secondary fluid flow at high mass flow Dms, with a speed vs and a pressure Ps,
• the injection means being adapted to deliver a primary fluid Fp having a pressure and a speed much higher than those of the secondary fluid, and are arranged so as to allow obtaining, inside the fluid supply channel, of a homogeneous mixture having a high mass flow rate equal to the sum (Dms + Dmp) of the primary and secondary fluids, and a speed flow towards the low turbine relative to the speed of the primary fluid Fp,
• the ejection channel having an outlet section capable of adapting the pressure level at the outlet substantially to that of the fluid present around the ejection section.

• des moyens de mesure d'une grandeur représentative de la vitesse de rotation de la turbine,
• des moyens d'acquisition de la vitesse de rotation mesurée,
• des moyens de traitement adaptés pour comparer la vitesse de rotation mesurée, avec une vitesse de rotation de consigne,
• des actuateurs adaptés pour réguler des paramètres fonctionnels et/ou dimensionnels de l'écoulement pour faire coïncider la valeur mesurée de la vitesse de rotation avec la valeur de consigne de cette vitesse, et
• une vanne d'arrêt.

Advantageously, the device is adapted to drive a turbine in rotation at a variable set speed and for this purpose comprises control and regulation means (50) comprising:

• means for measuring a quantity representative of the speed of rotation of the turbine,
• means for acquiring the measured speed of rotation,
• processing means suitable for comparing the measured rotation speed with a set rotation speed,
• actuators adapted to regulate functional and / or dimensional parameters of the flow in order to make the measured value of the rotation speed coincide with the set value of this speed, and
• a shut-off valve.

Thanks to such arrangements, a nominal operating point of the turbine is obtained, for a high torque, and a low speed of rotation compared to that obtained without the use of such arrangements on a comparable turbine.

Advantageously, the device according to the invention is provided with actuators adapted to vary the intake section of the primary and secondary fluids, as well as the section of the ejection channel. It is thus possible to modify the nominal operating point of the turbine at will and to adapt it continuously to the set operating point.

• la figure 1 est une vue schématique illustrant le procédé de fonctionnement du dispositif selon l'invention,
• la figure 2 est une vue en coupe longitudinale d'un dispositif à turbine selon la présente invention,
• les figures 3 et 4 sont des vues respectivement en coupe longitudinale et de dessus d'une première variante de réalisation d'un dispositif selon l'invention,
• la figure 5 est une vue en coupe longitudinale d'une deuxième variante de réalisation du dispositif selon l'invention,
• la figure 6 est une vue en coupe longitudinale d'une troisième variante de réalisation du dispositif selon l'invention,
• la figure 7 est un agrandissement du détail référencé E à la figure 6 et,
• la figure 8 est une vue schématique en perspective représentant une aube montée sur un moyeu, et destinée à former une turbine pouvant être utilisée pour le dispositif selon l'invention.

Other objects, characteristics or advantages of the invention will emerge from the description which follows, by way of example, and with reference to the appended figures in which:

• FIG. 1 is a schematic view illustrating the operating method of the device according to the invention,
• FIG. 2 is a view in longitudinal section of a turbine device according to the present invention,
• FIGS. 3 and 4 are views respectively in longitudinal section and from above of a first alternative embodiment of a device according to the invention,
• FIG. 5 is a view in longitudinal section of a second alternative embodiment of the device according to the invention,
• FIG. 6 is a view in longitudinal section of a third alternative embodiment of the device according to the invention,
• FIG. 7 is an enlargement of the detail referenced E in FIG. 6 and,
• Figure 8 is a schematic perspective view showing a blade mounted on a hub, and intended to form a turbine which can be used for the device according to the invention.

As already indicated, the aim of the present invention is to drive a turbine in rotation, with a relatively low speed of rotation ω, of the order of 0 to 60,000 rpm, but with a high torque C. Thus, the product C.ω which gives the power P of the turbine remains high, without however the speed of rotation ω being.

To this end, the method of driving the turbine in rotation according to the invention is described below.

• injecter un fluide primaire dans le canal amont d'amenée de fluide. Cette injection se fait à une pression Pp, une vitesse Vp et un débit masse dmp déterminés,
• admettre un fluide secondaire dans le canal amont d'amenée. La pression ps et la vitesse vs de ce fluide secondaire sont inférieures à celles du fluide primaire. Le débit masse de ce fluide secondaire est dms,
• mélanger dans le canal d'amenée les fluides primaire et secondaire. Le mélange ainsi obtenu présente une vitesse Vm et une pression Pm plus élevées que celles du fluide secondaire, et inférieures à celles du fluide primaire. Le débit-masse Dmm de ce mélange de fluide est égal à la somme des débits masse dmp + Dms des fluides primaire et secondaire,
• diriger le mélange de fluides vers la turbine,
• entraîner en rotation la turbine, par le passage du mélange de fluide, et
• éjecter le mélange de fluide ayant traversé la turbine vers l'extérieur.

The turbine being placed between an upstream fluid supply channel and a downstream ejection channel, the method according to the invention consists in:

• inject a primary fluid into the upstream fluid supply channel. This injection takes place at a pressure Pp, a speed Vp and a determined mass flow dmp,
• admit a secondary fluid into the upstream inlet channel. The pressure ps and the speed vs of this secondary fluid are lower than those of the primary fluid. The mass flow rate of this secondary fluid is dms,
• mix the primary and secondary fluids in the supply channel. The mixture thus obtained has a speed Vm and a pressure Pm higher than those of the secondary fluid, and lower than those of the primary fluid. The mass flow Dmm of this fluid mixture is equal to the sum of the mass flows dmp + Dms of the primary and secondary fluids,
• direct the mixture of fluids towards the turbine,
• drive the turbine in rotation, by the passage of the fluid mixture, and
• eject the mixture of fluid having passed through the turbine towards the outside.

• mesurer en continu un paramètre fonction de la vitesse de rotation de la turbine,
• comparer cette vitesse de rotation mesurée à une vitesse de consigne. Cette vitesse de rotation mesurée est fonction entre autres des paramètres dimensionsionnels et fonctionnels de l'écoulement,
• modifier en continu un ou plusieurs paramètres de l'écoulement pour adapter le point de fonctionnement nominal de la turbine au point de fonctionnement de consigne.

Advantageously, this method makes it possible to drive a turbine in rotation according to a variable setpoint parameter and also consists in:

• continuously measure a parameter depending on the speed of rotation of the turbine,
• compare this measured rotation speed with a set speed. This measured rotation speed is a function, among other things, of the dimensional and functional parameters of the flow,
• continuously modify one or more flow parameters to adapt the nominal operating point of the turbine to the set operating point.

Advantageously, a modification is made to the dimensional parameters of the turbine device (variation of the inlet section of the secondary fluid, of the section of injection of the primary fluid and of the section of ejection of the ejection channel). As a result, the nominal operating point of the turbine is modified and the actual rotation speed is continuously regulated so that it corresponds to the set rotation speed.

The turbine device according to the invention is described below.

• un canal amont d'amenée de fluide 11,
• une turbine 12,
• un canal aval d'éjection de fluide 13,
• des moyens d'injection 14, et
• des moyens de contrôle et de régulation 50 (figure 1). Ces moyens 50 sont constitués par :
• une vanne d'arrêt 22,
• des moyens de mesure 19,
• des moyens d'acquisition 20, et
• des moyens de régulation 52 comportant :
  • . des moyens de traitement 21, et
  • . des actuateurs 51.

According to the embodiment shown in FIGS. 1 and 2, the device 10 according to the invention essentially comprises (FIG. 2):

• an upstream fluid supply channel 11,
• a turbine 12,
• a downstream fluid ejection channel 13,
• injection means 14, and
• control and regulation means 50 (FIG. 1). These means 50 consist of:
• a stop valve 22,
• measuring means 19,
• acquisition means 20, and
• regulation means 52 comprising:
  • . processing means 21, and
  • . actuators 51.

The injection means 14 (FIG. 1) of primary fluid Fp into the supply channel 11 is placed at the upstream part 11a of the supply channel 11. This means 14 includes a nozzle 15.

A secondary fluid Fs is sucked into the upstream supply channel by the depression created by the injection of the primary fluid. Once in the upstream supply channel, these two fluids mix in the downstream part 11b of the supply channel 11. The length of this supply channel partly conditions the characteristics of the mixture of the fluids.

If necessary, a converging channel 16 is placed upstream of the turbine 12 and is intended to accelerate the mixing of fluids.

A deflector means 17, called the upstream distributor, constituted by a fixed turbine wheel is placed upstream of the turbine 12, in order to direct the mixture of fluids optimally on blades 18 of the turbine 12.

The turbine 12 is thus driven in rotation.

The mixture of fluids is then ejected through the ejection channel 13 outside the turbine device. The purpose of such a channel is to adapt in particular the pressure of the fluid leaving the turbine to that of the fluid present around the ejection section.

The rotation of the turbine is used for any application, for example for driving tools, etc. as will be detailed with reference to FIG. 3.

• des moyens de mesure 19 d'une grandeur représentative de la vitesse de rotation de la turbine 12. Ces moyens de mesure sont constitués par deux capteurs piézoélectriques (un seul est représenté à la figure 1) mesurant les pressions statiques à l'amont et à l'aval de la turbine dans des zones d'écoulement non perturbées. La présence de ces deux capteurs a pour but de multiplier les points de mesure, afin de comparer leur valeur et d'activer si nécessaire une vanne d'arrêt 22 installée sur la canalisation d'alimentation en fluide primaire. Ces moyens doivent être fiables et donner des mesures répétitives et significatives,
• des moyens d'acquisition 20, recevant et adaptant les grandeurs électriques mesurées par les moyens 19,
• des moyens de traitement 21 adaptés pour définir la vitesse de rotation instantanée de la turbine (vitesse mesurée), et comparer cette vitesse de rotation mesurée à une vitesse de rotation de consigne. Si les vitesses mesurées et de consigne diffèrent, le moyen de traitement envoie un ordre de commande,
• des actuateurs 51 constitués ici par un régulateur de pression recevant l'ordre de commande des moyens de traitement et adaptés pour modifier la pression d'injection du fluide primaire et rendre égales les vitesses de rotation mesurées et de consigne, et
• une vanne d'arrêt de sécurité 22 placée à l'amont du dispositif d'injection de fluide primaire afin de stopper le fonctionnement du dispositif en cas de nécessité. Cette vanne d'arrêt est également commandée par le moyen de traitement 21.

The turbine device is also associated with control and regulation means 50. These means 50 comprise:

• measuring means 19 of a magnitude representative of the speed of rotation of the turbine 12. These measuring means consist of two piezoelectric sensors (only one is shown in FIG. 1) measuring the static pressures upstream and at downstream of the turbine in undisturbed flow zones. The purpose of these two sensors is to multiply the measurement points, in order to compare their value and activate if necessary a stop valve 22 installed on the primary fluid supply pipe. These means must be reliable and give repetitive and significant measures,
• acquisition means 20, receiving and adapting the electrical quantities measured by the means 19,
• processing means 21 adapted to define the instantaneous speed of rotation of the turbine (measured speed), and compare this measured speed of rotation to a set speed of rotation. If the measured and target speeds differ, the processing means sends a command order,
• actuators 51 constituted here by a pressure regulator receiving the command to control the processing means and adapted to modify the injection pressure of the primary fluid and make the measured and set speeds of rotation equal, and
• a safety shut-off valve 22 placed upstream of the primary fluid injection device so to stop the operation of the device if necessary. This stop valve is also controlled by the processing means 21.

Thus, the device according to the invention is continuously regulated by the control and regulation assembly 50.

As a variant of this device, the converging channel 16 can be integrated into the upstream distributor 17.

As shown in Figures 3 and 4, the injection means 14 can take different forms.

In the example shown in Figures 3 and 4, the means corresponding to those described in Figure 2 are referenced as in Figure 2, but increased by one hundred unit.

Figures 3 and 4 show a first variant of the device according to the invention.

The injection means 114 consist of two pipes 130 opening into the side wall of the upstream supply channel 111. Advantageously, these pipes are inclined at an angle α (FIG. 3) determined relative to the axis A of the device, and an angle β (FIG. 4) between the axis of the pipe 130 and a diametrical plane F passing through the axis of the turbine and the center of the injection section at the wall of the channel 111.

Thus, the primary fluid Fp drives the secondary fluid Fs in a helical trajectory (helical injection) along the walls (parietal injection) of the upstream supply channel 111. This type of injection is called parieto-helical injection.

This injection mode has the advantage of being self-adapting. In fact, when the speed of rotation of the turbine increases, the mass flow Dms of the secondary fluid also increases. The speed of the secondary fluid in the injection plane of the primary fluid in the supply channel has a module which increases and a direction which tends to approach the axis of the turbine. As a result, the flow of the mixture has a general incidence which decreases in the inlet plane of the turbine. Therefore, the available power tends to decrease if the increase in secondary mass flow is not taken into account and vice versa if the speed of rotation of the turbine decreases. This then results in a turbine device, whose free rotation regime (that is to say without resistive torque generated by the external medium on the axis of the turbine) is self-limited, and which has a strong peak of power for a low speed of rotation, characterizing the self-adaptation phenomenon of the flow.

By way of example, the speed of rotation corresponding to such a power peak is 12,000 rpm for a turbine with a diameter of 30 mm and a supply of primary fluid of the parieto helical type with three equally distributed inlet channels. along the circumference of the inlet channel (the angles α and β of inclination of the inlet pipes being 45 °).

It should be noted that the number of pipes 130 for injecting primary fluid may vary. For a better homogeneity of the primary fluid / secondary fluid mixture, it is advantageous to have a plurality of injection pipes distributed around the circumference of the supply channel.

Note that, in the embodiment presented in Figures 3 and 4, the ejection channel 113 has an axial direction. It will also be noted that with such an injection mode (helical parieto), it is not necessary to place a deflector device upstream of the turbine 112.

• l'angle α, ce qui a pour but de faire varier la vitesse nominale du point de fonctionnement nominal et/ou
• l'angle β, ce qui a pour but de modifier les caractéristiques de fonctionnement, prioritairement en débit masse secondaire, donc la puissance maximale au point de fonctionnement nominal.

According to an alternative embodiment (not shown) (the angle α fixing the initial slope of the injection propeller, the angle β defining the nominal diameter of the injection of this propeller), the following is varied continuously:

• angle α, which aims to vary the nominal speed of the nominal operating point and / or
• the angle β, which aims to modify the operating characteristics, primarily in secondary mass flow, therefore the maximum power at the nominal operating point.

It will be noted that the axis of rotation of the turbine can be directly constituted by a mandrel rod 160 of a tool 180.

• des efforts proportionnels à l'inertie des organes de transmission et au carré de la vitesse de rotation et
• la nécessité de mettre en oeuvre une transmission dont la géométrie puisse varier par la mobilité relative d'un certain nombre de pièces constitutives afin notamment de pouvoir fixer l'outil sur la transmission.

The transmission of the engine force from a turbine to a tool poses technical implementation problems such as:

• forces proportional to the inertia of the transmission members and to the square of the speed of rotation and
• the need to implement a transmission, the geometry of which can vary by the relative mobility of a certain number of constituent parts in order in particular to be able to fix the tool on the transmission.

However, in the case of the tool-turbine assembly shown in FIG. 3 and, taking into account the moderate rotational speeds of the device, it is possible to use simple, rustic and inexpensive guide bearings in rotation and translation, commonly used in the industry to date.

In the example of such an embodiment, the turbine 112 is force-fitted onto the rear part 160 (mandrel rod) of the cylindrical tool 180, which can be a cutter.

The tool may have, for this purpose, at its mandrel rod, a set of small rectilinear edges oriented along the axis of rotation of said tool.

Alternatively, the tool can be associated with an intermediate fixing part (not shown).

In the example shown, the suspension bearing of the tool-turbine assembly is constituted by the bearings 183 and 184. The bearing 183 abuts on the hub of the turbine. A spacer 185, mounted just sliding on said tool, maintains the spacing with the bearing 184 so as to ensure the necessary functional clearance along the axis of rotation at the level of the bearing body 186.

A ring 187, made of a material whose coefficient of thermal expansion is lower than that of the material constituting said tool is mounted tight on said tool and comes to immobilize in translation (along the axis of rotation of the tool) the bearings 183 and 184 and the spacer 185.

The assembly thus produced consists of a small number of simple, inexpensive and low inertia parts around the axis of rotation.

According to the embodiment shown in FIG. 5 (second variant), the mode of injection of the primary fluid is still different.

As before, the references of FIG. 2 have been used in this figure, increased by two units of hundreds.

The injection means 214 here consists of four conduits 230 (three are shown) opening out inside the supply channel 211, so that the primary fluid Fp is injected parallel to the axis A of the device and the along the walls. Such an injection mode is said to be parietal.

As in the example in Figure 2, the primary fluid drives the secondary fluid to the turbine.

It will be noted that the number of pipes 230 for introducing the primary fluid may vary and that, preferably, the plurality of pipes is distributed along the circumference of the supply channel 211.

As a variant, each pipe 230 can pivot around its horizontal axis, to generate a flow that is no longer axial but helical. In this case, a helico-parietal flow is obtained with the advantages cited with reference to FIGS. 3 and 4, and associated with an upstream distributor 217.

Figures 6 and 7 show a third alternative embodiment of the turbine device according to the invention. As before, the references of FIG. 2 are repeated increased by three units of a hundred for the equivalent means represented in FIGS. 2 and 6.

• une injection d'air primaire de type annulaire et au niveau des parois (injection pariéto-annulaire),
• des actuateurs adaptés pour faire varier la section d'entrée du fluide secondaire, la section d'injection du fluide primaire et la section d'éjection du canal d'éjection.

The device 310 according to FIG. 6 has the particularity of having:

• an injection of primary air of annular type and at the level of the walls (parieto-annular injection),
• actuators adapted to vary the inlet section of the secondary fluid, the injection section of the primary fluid and the ejection section of the ejection channel.

In fact, the secondary fluid is introduced into the supply channel by an inlet device 350 having an opening 351 with variable section. The input device is screwed and unscrewed on the body of the supply channel 311 by means of a thread 352.

This screwing (or unscrewing) is controlled by a means for modifying the input section, namely the actuator 353. This actuator 353 is itself controlled by the processing means 321. As shown by arrow B, l action of this actuator 353 makes it possible to vary the inlet section of the secondary fluid.

Correspondingly, an actuator 354 for varying the ejection section of the device allows the screwing or unscrewing of an output device 356 via a thread 357. As shown by arrow C, the action of this actuator 354 makes it possible to vary the ejection section.

As before, the actuator 354 is controlled by the processing means 321.

An actuator 355 making it possible to vary the section for injecting the primary fluid into the supply channel 311 is also provided.

The primary fluid Fp is introduced into the supply channel 311 passing through a minimum section 358 called the neck section of the flow, this section varying through the actuator 355.

This neck is created (FIG. 7), on the one hand, by an annular bulge 359 of the wall of the supply channel 311 and, on the other hand, by a displaceable element 360 placed in the upstream part 311a of the channel. brought 311 and opposite the annular bulge 359.

By sliding along the arrow D of the element 360, the section of the neck 358 of primary fluid supply is variable. Sliding takes place by screwing and unscrewing the movable element 360 in the supply channel 311 by means of the thread 361.

It will be noted that the introduction of the primary fluid Fp into the supply channel 311 takes place parallel to the longitudinal axis A of the device. This injection is carried out around the entire circumference of the inlet channel and near the walls. This injection is called parieto-annular injection.

As shown in FIG. 7, the respective shapes of the body 370 of the supply channel 311 and of the displaceable element 360 which faces it constitute an annular diverging convergent nozzle. Said annular diverging convergent nozzle, supplied with primary fluid by an annular section 371, therefore has a neck 358 and an outlet section 372 whose respective surfaces can vary when the actuator 355 drives the element 360 in translation. In the converging part from said nozzle, the primary fluid undergoes subsonic acceleration until reaching the sonic speed at said neck 358. In the divergent part of said nozzle, the primary fluid undergoes supersonic acceleration. In operation, the primary fluid supply pressure must be sufficient so that, taking into account the value of the surface of the injection section 372, the ejection of said primary fluid into the supply channel is supersonic and at a static pressure higher than that of said secondary fluid in section 373 of element 360. Indeed, it then creates on the outlet lips 374 of element 360 an expansion beam and a turbulent wake capable of promoting the exchange of energy between said primary and secondary fluids. In addition, the parietal injection following a convergent / divergent annular nozzle makes it possible, on the one hand, to increase the energy exchange surface between said primary and secondary fluids and, on the other hand, to obtain in the plane d input 375 (FIG. 6) of said distributor 317 has an optimum speed profile characterized in that the local average speed is all the more important as it is located near the head of the blades 318 of said distributor 317.

Such a dimensional and functional arrangement of a convergent / divergent nozzle at the level of the injection of the primary fluid can be generalized to all the injections of primary fluid, whatever the variant considered.

Such a device makes it possible, by acting on the dimensions of the primary and secondary fluid intake channels and on the dimension of the ejection channel, to vary the nominal operating point of the turbine.

Of course, all of the actuators 353, 354, 355 are controlled by the processing means 321.

Another variant of the ejection device consists in producing a duct ejection channel leading the fluid from the outlet plane of the turbine to the level of the intake of the secondary fluid and thus making it possible to recycle in the device itself a part of the ejected fluid.

The advantage of the device according to the invention, whatever the variant of embodiment chosen, resides in the fact that the torque delivered is significant for low rotational speeds and that the power delivered is comparable to that of existing turbines.

Now, blades will be described which can be used in each of the variants described above.

• Le bord d'attaque d'une aube est la portion de courbe située à l'extrémité amont de ladite aube et qui reçoit l'écoulement.
• Le bord de fuite d'une aube est la portion de courbe située à l'extrémité aval de ladite aube et qui voit s'échapper l'écoulement.
• Une aube est constituée d'une surface dite intrado et d'une surface dite extrado ; ces deux surfaces sont sécantes suivant les lignes de bord de fuite et de bord d'attaque.
• Un profil d'une aube est la courbe fermée résultant de l'intersection des surfaces intrado et extrado avec une surface cylindrique ayant pour axe celui du moyeu portant l'aube.
• La corde d'un profil est le segment de droite joignant sur un profil d'aube les points du bord de fuite et du bord d'attaque.
• Un angle de bord d'attaque est l'angle que fait une droite tangente au profil au point du bord d'attaque avec la direction de l'axe dudit moyeu.
• Un angle de bord de fuite est l'angle que fait une droite tangente au profil au point du bord de fuite avec la direction de l'axe du moyeu.
• L'épaisseur d'un profil en un point donné de l'intrado est la longueur du segment de droite délimitée par ledit point de l'intrado et le point de l'extrado défini par l'intersection de l'extrado avec une droite perpendiculaire à l'intrado en cedit point de l'intrado.
• Le pied d'une aube est la partie de l'aube jouxtant le moyeu.
• La tête d'une aube est la partie de l'aube la plus éloignée du moyeu.

However, to facilitate understanding of this description, we first recall the definitions of the main terms used:

• The leading edge of a blade is the portion of the curve located at the upstream end of said blade and which receives the flow.
• The trailing edge of a blade is the portion of the curve located at the downstream end of said blade and which sees the flow escape.
• A vane consists of a so-called intrado surface and a so-called extrado surface; these two surfaces intersect along the trailing edge and leading edge lines.
• A profile of a vane is the closed curve resulting from the intersection of the intrado and extrado surfaces with a cylindrical surface having as its axis that of the hub carrying the vane.
• The chord of a profile is the line segment joining on a blade profile the points of the trailing edge and the leading edge.
• A leading edge angle is the angle made by a straight line tangent to the profile at the point of the leading edge with the direction of the axis of said hub.
• A trailing edge angle is the angle made by a straight line tangent to the profile at the point of the trailing edge with the direction of the axis of the hub.
• The thickness of a profile at a given point on the lower surface is the length of the line segment delimited by said point on the lower surface and the point of the upper surface defined by the intersection of the upper surface with a perpendicular line. on the lower surface at this point of the lower surface.
• The foot of a blade is the part of the blade adjoining the hub.
• The head of a blade is the part of the blade furthest from the hub.

The blades are described with reference to FIG. 2, but could just as easily be used with the variants shown in FIGS. 3 to 6.

The turbine 12 (FIG. 8) is constituted by a cylindrical hub on which blades 18 which are circularly distributed are disposed radially. These blades are identical for the same turbine. The leading edge angles are constant along the leading edge for all the blades of the same turbine, the same for the trailing edge angles. The profile chord is constant for all the profiles of all the blades of the same turbine. The thickness of a profile is constant, except in the immediate vicinity of the trailing edge and the leading edge.

As a variant, the thickness of the profiles of a blade increases from head to foot of the blade in order to take into account the increasing mechanical stresses from head to foot of the blade.

It will thus be noted that the blades have a constant chord, a constant thickness along a cylindrical section having as axis that of said turbine, constant leading edge angles, constant trailing edge angles, curved surfaces of intrado and upper surface generated by a conical surface whose apex is the point of intersection of the axis of said turbine with the planes, perpendicular to the axis of said turbine, of inlet for the upstream part and outlet for the downstream part, and the apex angle of which is a function of the leading edge angle for the upstream part and the trailing edge angle for the downstream part.

Such blades are simple to produce (machining, molding, etc.) and inexpensive.

In addition, such blades have the advantage, when the speed of the turbine increases, of also increasing the speed of the flow in the inter-blade channel. From a certain value of said flow speed, expansion and recompression significantly degrade the flow in the inter-vane channel. This results in a phenomenon of self-limitation of the free speed.

It will be noted that, thanks to the speeds of relatively low rotation (from 0 to 60,000 rpm), simple and common turbine suspension bearings can be used.

One of the advantages of the present invention is its lightness, its silent operation, its reliability. In addition, simple, inexpensive transmissions on the market can be easily adapted to such a turbine, for driving tools between 0 and 60,000 rpm.

Of course, the present invention is not limited to the embodiments chosen and encompasses any variant within the reach of ordinary skill in the art. In particular, it is possible as a variant to produce at the level of the ejection planes of the device a pressure lower than the general level of pressure prevailing in the environment external to the device. The nominal power level of the device then does not vary significantly; on the other hand, the mass flow injected decreases appreciably, this phenomenon characterizing the introduction of a second energy source materialized by the vacuum at the outlet of the ejection channel, to the detriment of the energy source defined by the primary fluid under pressure ; however, the precision of controlling the speed of rotation of the turbine by acting on the pressure Pp of injection of the primary fluid decreases.

Claims (25)

1. Method of driving a turbine (12, 112, 212, 312) in rotation, said turbine being connected to an upstream fluid admission channel (11, 111, 211, 311) and to a downstream ejection channel (13, 113, 213, 313), said method comprising the steps of:

   - admitting a secondary fluid Fs in thefluid admission channel (11, 111, 211, 311), said admission channel presenting an inlet section adapted to generate a secondary fluid flow with high mass flow Dms, with a velocity Vs and a pressure Ps,

   - simultaneously injecting a primary fluid Fp, presenting determined pressure Pp, velocity Vp, very much higher than those of the secondary fluid, and mass flow dmp, so as to obtain, in the fluid admission channel (11, 111, 211, 311), a homogeneous mixture presenting a high mass flow equal to the sum (Dsm + Dmp) of the primary and secondary fluids, and a flow velocity towards the turbine (12, 112, 212, 312) which is low relatively to the velocity of the primary fluid Fp,

   - driving the turbine in rotation by the passage of the mixture of fluid over blades (18, 118, 218, 318) of this turbine, and

   - ejecting the mixture of fluid by means of the fluid ejection channel (13, 113, 213, 313) of which the outlet section is designed to adapt the level of pressure at the outlet substantially to that of the fluid present in the vicinity of the ejection section.
2. Method according to Claim 1 for driving a turbine in rotation at a variable reference speed, characterized in that it consists in addition in:

   - continuously measuring a magnitude representative of the real speed of rotation ω of the turbine,

   - comparing this real speed of rotation with the reference speed of rotation,

   - continuously modifying one or more parameters of the flow for the nominal working point of the turbine to correspond to the reference working point.
3. Method according to Claim 1 or 2, characterized in that it consists in determining the nominal working point by:

   - modifying a section (351) for admission of the secondary fluid in the admission channel and/or by

   - modifying a section (358) for injection of the primary fluid in the admission channel and/or by

   - modifying a section of the fluid ejection channel and/or by

   - modifying the primary fluid injection pressure.
4. Method according to one of Claims 1 or 3, characterized in that the primary fluid Fp is injected in parietal manner in the admission channel (11,111,211,311).
5. Method according to one of the preceding Claims, characterized in that the primary fluid Fp is injected in parietal manner following an axial direction in the admission channel (11, 111, 211, 311).
6. Method according to one of Claims 1 to 4, characterized in that the primary fluid Fp is injected so that the mixture of the primary and secondary fluids is driven in a helicoidal movement.
7. Method according to Claim 6, characterized in that the helicoidal movement is parietal.
8. Method according to one of Claims 1 to 3, characterized in that the primary fluid is injected in the admission channel in annular manner.
9. Method according to one of the preceding Claims, characterized in that a primary fluid Fp is used, presenting a speed at the level of an injection section (372) which is clearly supersonic before introduction in the admission channel (311).
10. Method according to Claim 9, characterized in that it consists in mixing the primary and secondary fluids by means of expansion waves created by the supersonic primary fluid in the vicinity of its introduction in the admission channel.
11. Method according to one of the preceding Claims, characterized in that it further consists in calibrating angles α and β of the mixture of fluid in an inlet plane of the turbine.
12. Method according to one of the preceding Claims, characterized in that a magnitude representative of the speed of rotation ω of the turbine is measured by measuring the static pressure upstream and downstream of the turbine (12, 112, 212, 312).
13. Method according to one of the preceding Claims, in which the velocity of the mixed fluids is increased by passing it through a convergent channel (16, 116, 216, 316) upstream of the turbine (12, 112, 212, 312).
14. Turbine device carrying out the method according to one of Claims 1 to 13, comprising:

    - within a body presenting overall a symmetry of revolution, a turbine (12, 112, 212, 312), an upstream channel (11, 111, 211, 311) for admission of fluid towards the turbine, and a fluid ejection downstream channel (13, 113, 213, 313),

    - means (14, 114, 214, 314) for injecting in the fluid admission channel a primary fluid Fp presenting determined pressure, velocity and mass flow Dmp,

    - the fluid admission channel (11, 111, 211, 311) presenting an inlet section adapted to generate a secondary fluid flow with high mass flow Dsm, with a velocity vs and a pressure Ps,

    - the injection means (14, 114, 214, 314) being adapted to deliver a primary fluid Fp presenting a pressure and a velocity very much higher than those of the secondary fluid, and being disposed so as to allow a homogeneous mixture to be obtained inside the fluid admission channel, which presented a high mass flow equal to the sum (Dms + Dmp) of the primary and secondary fluids, and a flow velocity towards the turbine (12, 112, 212, 312) which is low relatively to the speed of the primary fluid Fp,

    - the ejection channel (13, 113, 213, 313) presenting an outlet section capable of adapting the level of pressure at the outlet substantially to that of the fluid present in the vicinity of the ejection section.
15. Device according to Claim 14, characterized in that it is adapted to drive the turbine at a variable reference speed, said device further comprising control and regulation means (50) comprising:

    - means (19) for measuring a magnitude representative of the speed of rotation ω of the turbine,

    - means (20) for acquiring the speed of rotation measured,

    - processing means (21) adapted to compare the speed of rotation measured with a reference speed of rotation,

    - actuators (51) adapted to regulate (21) functional and/or dimensional parameters of the flow to cause the measured value of the speed of rotation to coincide with the reference value of this speed, and

    - a stop valve (22).
16. Device according to Claim 14 or 15, in which the injection means (14) is an injector presenting a nozzle.
17. Device according to Claim 14 or 16, characterized in that the injection means (114, 214) comprises at least one conduit (130, 230) adapted to introduce the primary fluid along the wall of the admission channel.
18. Device according to Claim 14 or 15, characterized in that the injection means (114) comprises at least one conduit (130) of given inclination α with respect to an axis A of the admission channel and of inclination β with respect to an axis F of this admission channel, adapted to deliver the primary fluid Fp in the admission channel along a helicoidal path.
19. Device according to Claim 14 or 15, characterized in that the injection means (314) is constituted by an annular space inside the admission channel, said annular space presenting a convergent section, a variable neck section (358) and a divergent section.
20. Device according to one of Claims 14 to 19, characterized in that the ejection channel (13, 113, 213, 313) is oriented radially and/or axially.
21. Device according to one of Claims 14 to 20, characterized in that the measuring means are constituted by at least two sensors (19) adapted to measure the static pressures prevailing upstream and/or downstream of the turbine.
22. Device according to one of Claims 14 to 21, characterized in that it further comprises:

    - an actuator (355) adapted to vary the section of injection of the primary fluid and/or

    - an actuator (353) adapted to vary the section of admission of the secondary fluid and/or

    - an actuator (354) adapted to vary the section of ejection of the mixture of fluid.
23. Device according to Claim 22, characterized in that each actuator (353, 354, 355) is controlled by the processing means (21).
24. Device according to one of Claims 14 to 23, characterized in that the rotation shaft of the turbine is constituted by a mandrel rod (160) of a tool (180) driven by the turbine.
25. Device according to one of Claims 14 to 24, characterized in that the turbine and/or an upstream distributor are provided with blades presenting a constant chord, a constant thickness along a cylindrical section having for axis that of said turbine, constant leading edge angles, constant trailing edge angles, curved under and upper surfaces generated by a conical surface whose apex is the point of intersection of the axis of said turbine with the planes, perpendicular to the axis of said turbine, inlet for the upstream part and outlet for the downstream part, and of which the apex angle is a function of the leading edge angle for the upstream part and of the trailing edge angle for the downstream part.

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