WO2000039440A1

WO2000039440A1 - Rotary turbine engine of the reaction type

Info

Publication number: WO2000039440A1
Application number: PCT/IT1999/000424
Authority: WO
Inventors: Giovanbattista Greco
Original assignee: Individual
Current assignee: Individual
Priority date: 1998-12-28
Filing date: 1999-12-27
Publication date: 2000-07-06
Anticipated expiration: 2001-06-28
Also published as: AU2001500A; ITRM980804A1; ITRM980804A0; IT1302949B1

Abstract

The invention relates to a rotary turbine engine of the reaction type, comprising an impeller (1) with shaped blades (2), an impeller rotation axis (3), an inlet of the fluid between the blades (4), combustion chambers (6) between said blades (2), and a fluid shaped outlet (5).

Description

ROTARY TURBINE ENGINE OF THE REACTION TYPE

The present invention relates to an internal combustion endothermic engine with reactive propulsion and "circular motion".

More specifically, the invention relates to an engine of the above kind remarkably simplified.

As it is well known, immediately after the Second World War, development of gas turbine propulsion allowed to accumulate a remarkable experience, particularly in the field of fluid mechanics and metal technology.

From these studies, a thrust derived to realise units able to replace the traditional reciprocating endothermic engine and steam turbine, even for terrestrial applications.

Various kind of turbo engines developed for terrestrial applications can be classified as high power "low" engines an little power "fast" engines.

The first one compete with diesel engines and steam turbines to be employed in fixed plants where, not being fundamental the weight and size reduction, it is possible to obtain a higher thermal efficiency of the cycle, also thanks to the adoption of numerous devices and solutions allowing to make different energy recovery.

However, machines obtained are technically complicated, so that some of these arrangements cannot be applied on smaller machines, thus limiting their use. Reference is made to solution where the inner cooling of the blades that have to withstand to very strong mechanical and thermal stresses.

Another kind of classification adopted for turbo-propulsors for terrestrial applications is that of the power transmission mode: machines with a single axis or machines with two or more axis. Said solutions, that are well known and therefore will be not described further in the following, always provide a mechanical (shaft) and fluid mechanical (gas + turbine or gas + turbines) connection. Furthermore, turbo-propulsors can be constant pressure or constant volume propulsors.

In the constant pressure turbo-propulsors, air passes through the compressor and arrives within the combustion chamber with a higher pressure. Within the combustion chamber, fuel is continuously injected by a suitable injection pump. The combustion, electrically triggered at the start, is constant, thus producing a fast increase of the temperature and of the fluid volume, which, expanding through the turbine impeller, produces work, a part of which is absorbed by the compressor and the remainder is used as useful work.

Exhaust gases outflow and expand up to atmospheric pressure. Obviously, the functional scheme is remarkably complicated when one or more of the following operations are desired: - cooling of air between a compression stage and the other one;

- repetition of the combustion and thus of the expansion one or more times;

- partial recovery of the heat contained in the exhaust gases to heat air before the combustion.

Constant volume turbo-propulsors have been studied at the beginning before it appeared that this one was the scheme that could give the best results. Then, this solution has been put aside, or in any case it has no more been pre-eminently developed, in view of its realisation complexity.

With respect to the constant pressure turbo-propulsors, it differs for the fact that the combustion chamber is provided with intake and discharge valves, or, in some cases, also with the intake valves.

Combustion, in the first case occurs with a perfectly constant volume, and in the second case with an almost constant volume.

Intake valves can be automatic valves, so that they automatically close due to the effect of the fluid expansion, and open again due to the suction effect when gases outflow toward the turbine.

This kind of turbines has the feature that with the same temperature of compressed air, they reach maximum temperatures of the combustion cycle remarkably higher and thus with a higher ideal thermal efficiency.

However, this functional scheme has big mechanical and fluid mechanical difficulties due to the presence of valves and to the sudden flow variations within the ducts and on the turbine blades which are subjected to high limit temperatures for metals. In aeronautical propulsion, turbojet have been successfully developed, providing the direct utilisation of the gas jet coming out from the combustion, and thus from the turbine, allowing to easily reach higher speed, by the ejection of gaseous mass in the direction opposite to the vehicle motion with determined force F.

According to the principle of action and reaction, fluid mass flowing out will exert on the vehicle a thrust S= -F, S meaning the thrust suitable to determine propulsion.

For rectors, in order to obtain good propulsion efficiencies, rather high speeds are necessary, close to the gas ejection speed.

Generally speaking, a turbojet comprises a diffuser or dynamic drive, a compressor, and a series of combustion chambers, a turbine and an entrance cone, wherein the expansion is completed up to reaching the atmospheric pressure producing the increase of the gases kinetic energy. Considering the diffuser as first stage of compressor and entrance cone as the last stage of the turbine, thermal cycle of fluid is completely similar to the one of the gas turbine plants with adiabatic depression and expansion without recovery.

However, differently with respect to the above systems, only the quota of enthalpic drop sufficient to operate the compressor is used in the turbine of turbojet, while the residual enthalpic drop is used in the entrance cone and converted into kinetic energy in order to generate propulsive thrust.

As it is well known, turbojet can be validly employed with good efficiencies with speed ranging between 800 - 1000 Km/h and more than 1500 - 2000 Km/h in the modern military supersonic aeroplanes.

In this kind of engines, a system to increase the thrust and to reduce the consumption at very high speed provides increasing the outflow sending cold air toward the jet, making it passing about the engine. A remarkable mass of air participating to the propulsive action is added to the exhaust gas mass; speed deriving from the jet diminishes, but the total mass increases much more, so that also the thrust is increased.

Efficiency of a turbine increases in function of the air compression ratio at the entrance within the combustion chamber and increases with a higher combustion temperature. Practically, a limit exist both for the compression ratio, that cannot be increased beyond certain values, since at the high pressures losses in compressor are too high, and for the maximum combustion temperature that would involve high temperature also in the turbines, where mechanical stresses are, beyond certain limits, unsustainable along with the high exercise temperatures. Thus two main problems can be individuated, namely aerodynamic and technological problems.

These and other problems have been faced up and solved, according to the present invention, by a solution allowing to remarkably simplify the structure of the engine.

It is therefore specific object of the present invention an internal combustion endothermic engine, comprising an impeller with shaped blades, an impeller rotation axis, an inlet of the fluid between the blades, combustion chambers between said blades, and a fluid shaped outlet. Preferably, according to the invention, said impeller is comprised of a centrifugal compressor or of an axial compressor.

According to the invention, downward said impeller, an axial or centripetal turbine can be provided, within which the discharge of said impeller passes. Always according to the invention, said impeller can be a one or more stage impeller, with the heaters support impeller, or it can be comprised of a centrifugal compressor for the part supporting the heaters, preceded by a one or more stage axial compressor.

Still according to the invention, said compressor can be provided of a speed limiting device to limit the "sonic" effect (particularly on the centrifugal compressor).

Furthermore, according to the invention, it can be provided a one or more stage volumetric compressor before the heaters support impeller, that can be a centrifugal or axial impeller. Furthermore, said heaters support impeller can be provided of the possibility of singularly intercepting the same by servo controls.

Gas exhaust or air inlet within the impeller can be realised on the peripheral side or on the front and/or rear, inner face.

Preferably, according to the invention, one or more heaters can be provided in said impeller.

Said heaters can be realised with an automatic air inlet valve, that is opened by the centrifugal force and is closed by the fluid expansion or inlet or outlet (discharge) closure valve with electromechanical or pneumatic control.

Furthermore, said heaters can be realised with air and/or fuel heating before the combustion, with heat exchanger or electric resistances fed by the current generator, or with precombustion chamber ignition with or without heating.

Always according to the invention, said heaters can be realised with direct injection within the flame tube.

Still according to the invention, said heaters can provide the insertion of a device to increase vortexes and thus the air - fuel combustion.

Furthermore, according to the invention, said heaters can be provided with air parzializzazione to guarantee the proper stoichiometric ratio, and thus diluting afterwards the mixture. For the injection within the combustion chamber, it can be provided, according to the invention, electric or pneumatic operated injectors, with or without fuel pressurisation pump.

Furthermore, for ignition within the same combustion chamber a glow plug with or without preheating, an ignition by auxiliary injector with or without prechamber, an ignition with a downward injector to trigger a post- combustion (rapid instantaneous increase of power), an ignition with electricity feeding from an outer generator (by brush collector on a shaft or inside, by conductors integral with the rotation shaft and thus with the impeller), can be provided. Still according to the invention, it can be provided a by-pass of a part of the heated air, directly on the exhaust collector (ejector) or of a cold autonomous air flow rate fed from another dynamic feed opening.

Further, according to the invention, said engine provides the flow of intake and exhaust air in the same direction, or according to a direction radially or axially different with respect to the rotation direction according to the constructive features chosen for convenience and/or in function of the engine application.

Furthermore, the engine according to the invention can be started by an auxiliary start engine, or by compressed air, e.g. by and electro blower. This would avoid some mechanical connections and the engine could switch off each time a transmission positive work on the shaft is not necessary, and rapidly switch on again following a control when necessary, thus contributing to the saving of consumption and to the pollution reduction. In case of city traffic, the engine could continuously be alternated with an electric traction (when in low charge conditions), being it possible to better manage the switching on/ switching off with respect to an explosion engine. A system to control the availability of accumulation of electric energy could limit this kind of alternation to allow the charge.

Finally, said endothermic engine can have a pressure proof heater (s) (function and constant volume with intake and delivery valves) or holed for the dilution with cold air directly during the combustion. The present invention will be now described, for illustrative but not limitative purposes, according to its preferred embodiments, with particular reference to the figures of the enclosed drawings, wherein: figure 1 is a schematic view of a first embodiment of the endothermic engine according to the invention; figure 2 is a schematic view of a second embodiment of the endothermic engine according to the invention; figure 3 is a schematic section view of the engine according to the invention; and figure 4 is a second schematic section view of the endothermic engine according to the invention.

Observing first figures 1 and 2, the endothermic engine according to the invention substantially looks like a centrifugal compressor

1 , with blades 2, with the substantial technical - functional difference that combustion, and thus expansion of fluid, is realised between blades 2 into a suitable heater, close to the peripheral end.

Impeller 1 has a rotation axis 3, with the inlet of air 4 parallel to the same axis 3 in the embodiment of figure 1, and tangential in the embodiment of figure 2, and a exhaust 5 of burned gases air.

In the peripheral end of the blades 2 a combustion chamber 6 is provided, possibly with an automatic valve 7, ignition sparkplug 8 and fuel injector 9. By arrow A, the direction of impeller is indicated .

Fluid exits from the exhaust duct 5, which is suitably shaped in such a way to transform the pressure energy taken for the effect of the combustion into speed kinetic energy. In this way optimum operation conditions are created to be able to actuate a turbojet. If, for example, the impeller would be rotated with very high speed, obliging the same to rotate on itself and forcing the same to a rotary motion, and at the same time a continuously changed air flow would be fed (which is not realisable if a deviation of the dynamic fluid path is actuated, that would be naturally created), with the fuel and the electrical energy to ignite the combustion, the speed acquired directly using the propulsive thrust created by reaction can be exploited, to obtain a useful work on the rotation shaft coinciding with the axis 3 about which the same impeller rotates. Clearly, it is necessary that the two fluids (air entering and exhaust gas) are maintained separated to avoid an unavoidable by-pass of exhaust gases that would be sucked in the intake.

At the speed reached, it is no more necessary an high air compression ratio, and mainly the fluid mechanics connection is eliminated, created by exhaust gases and turbine blades since thrust occurs downward the combustion chamber, directly on the same impeller.

By these two simplifications, it is obtained what mentioned in the preceding, since the eventual compressor would work with a compression ratio that could be lower and thus with reduced losses and an optimum efficiency, and the problems relevant to the mechanical technology and the materials that at present, mainly for little size machines, imposed limitations, have been drastically solved since it has been eliminated the turbine downward the combustion, using only an impeller (which has a simpler mechanical construction, and is more strong).

By the solution suggested according to the present invention, high temperatures can be quietly reached, also in view of the simple structure of the machine, mainly with respect to an explosion endothermic engine also providing, due to the mechanical, thermodynamical and material resistance problems, the lubrication and the continuous cooling of material more stressed comprising the engine.

The same cooling of materials is a dissipation of the power as thermic energy. Further, by this solution, sliding friction are reduced to the minimum since an perfectly balanced and statically and dynamically equilibrated endothermic engine is obtained.

Thus, motion is perfectly uniform and circular without any kind of unbalancing, and by a suitable insulation the engine can be made perfectly noiseless maintaining a weight - power ratio very low, mainly if compared with the alternating engine.

In case it is desired to obtain even more elevated performances, to further increase the efficiency, a lot of exhaust gas energy can be recovered by an axial or centripetal turbine integral with impeller 1 , i.e. provided on the same axis 3 or on a different axis or by the exhaust gas thermic energy recovery which is obtained by a heat exchanger with the advantage of the primary combustion air, immediately after the compression stage. As shown in figure 1 , in its simplest schematic configuration, machine is fed with fuel through the central hollow pin 4 by a standard injection pump (in case it is a liquid fuel) and mechanical sealing on the end part of the pin, by pneumatic mechanical injectors or electro injectors controlled in parallel with the ignition. In a preferred embodiment, not shown, ignition can be obtained by surface discharge sparking plugs 8, self-fed by a generator, the rotor portion of which is integral with the impeller and the stator part of which is fixed to the fix structure, thus feeding could occur through the rotation shaft (inside or fixed outside), thus exploiting the same circular motion to produce electrical energy.

Start can be actuated by auxiliary starting engine, compressed air (e.g. by an electro blower, that would avoid a mechanical connection) conferring the first rotation to the machine, which is not subjected to particular friction. Inserting the automatic intake and/or exhaust valves in the combustion chamber, it is obtained even with the engine stopped the possibility of creating a propulsive thrust useful for the start or in any case for low rotation regimes (starting frequency variation).

Being further the combustion chamber provided in the same element where the first or in any case the last compression stage occurs, it is easy to be able to recover main part of the heat to heat both the air flow before combustion (by fins inside the channel before the combustion chamber or by a real heat exchanger), and the same fuel that eventually can pass through the cavities of the impeller always close to the combustion chamber and thus injecting at an already high temperature.

In case it is desired to realise a better operation perfection, within the rotation shaft 3 an inner electronic panel (always autofed) can be installed, which, dialoguing by a radio transmission system with another fixed outer panel, thus allowing to continuously measure the speed by a proximity sensor to be able to continuously calculate the stoichiometric flow rate of the fuel mixture; continuously measuring the temperature of the compressor stages and eventually automatically actuating a heat exchanger, for cooling between a stage and the other one; continuously measuring the temperature of the combustion chamber and eventual preheating; continuously measuring the exhaust gas temperature; continuously checking the ignition of the electroinjectors and of the sparking plugs in function of the load regime and/or of the desired speed, e.g. changing the number and the frequency of operating heaters / reactors, thus realising the maximum exercise economy. Inserting a device of this kind, it is clear that outwardly is possible to install an electronic processor that can elaborate and manage these data in any way. To increase the reaction propulsive thrust and to reduce the consumption it is further possible to use a flux of exhaust gas with air bypassing the combustion.

By the solution according to the invention, it is further possible limit emission of CO and HC, without employing the catalyst on the exhaust since, in view of the high temperature of the expulsion gas, it is sufficient to add the air for the reaction downward the heaters before the heat exchanger with the fluid entering and to make this catalyst function exploited by the same suitably realised exchanger (thermal reactor with adjustment of secondary reaction air or catalytic reactor using elements comprised of typical materials already used of the known catalysts to realise the exchanger.

Also blow-by of a part of exhaust gases (that can be easily realised) contributes to the atmospheric pollution reduction, and particularly of the nitrogen oxide. The present invention has been described for illustrative but not limitative purposes, according to its preferred embodiments, but it is to be understood that modifications and/or changes can be introduced by those skilled in the art without departing from the relevant scope as defined in the enclosed claims.

Claims

1. Internal combustion endothermic engine, characterised in that it comprises an impeller with shaped blades, an impeller rotation axis, an inlet of the fluid between the blades, combustion chambers between said blades, and a fluid shaped outlet.

2. Internal combustion endothermic engine according to claim

1 , characterised in that said impeller is comprised of a centrifugal compressor or of an axial compressor.

3. Internal combustion endothermic engine according to one of the preceding claims, characterised in that downward said impeller, an axial or centripetal turbine is provided, within which the discharge of said impeller passes.

4. Internal combustion endothermic engine according to one of the preceding claims, characterised in that said impeller is a one or more stage impeller corresponding to the heaters support impeller.

5. Internal combustion endothermic engine according to claim

2, characterised in that said impeller is preceded by a one or more stage axial or centrifugal compressor.

6. Internal combustion endothermic engine according to one of the preceding claims, characterised in that said compressor is provided of a speed limiting device to limit the "sonic" effect (particularly on the centrifugal compressor).

7. Internal combustion endothermic engine according to one of the preceding claims, characterised in that it is provided a one or more stage volumetric compressor before the heaters support impeller, that can be a centrifugal or axial impeller.

8. Internal combustion endothermic engine according to one of the preceding claims, characterised in that said heaters support impeller is provided with the possibility of singularly intercepting the same by servo controls.

9. Internal combustion endothermic engine according to one of the preceding claims, characterised in that gas exhaust or air inlet within the impeller is realised on the peripheral side or on the front and/or rear, inner face.

10. Internal combustion endothermic engine according to one of the preceding claims, characterised in that one or more heaters is provided in said impeller.

11. Internal combustion endothermic engine according to one of the preceding claims, characterised in that said heaters are realised with an automatic air inlet valve, that is opened by the centrifugal force and is closed by the fluid expansion or inlet or outlet (discharge) closure valve with electromechanical or pneumatic control.

12. Internal combustion endothermic engine according to one of the preceding claims, characterised in that said heaters are realised with air and/or fuel heating before the combustion, with heat exchanger or electric resistances fed by the current generator, or with precombustion chamber ignition with or without heating.

13. Internal combustion endothermic engine according to one of the preceding claims, characterised in that said heaters are realised with direct injection within the flame tube.

14. Internal combustion endothermic engine according to one of the preceding claims, characterised in that said heaters provide the insertion of a device to increase vortexes and thus the air - fuel combustion.

15. Internal combustion endothermic engine according to one of the preceding claims, characterised in that said heaters are provided with air parzializzazione to guarantee the proper stoichiometric ratio, and thus diluting afterwards the mixture.

16. Internal combustion endothermic engine according to one of the preceding claims, characterised in that, for the injection within the combustion chamber, they are provided electric or pneumatic operated injectors, with or without fuel pressurisation pump (e.g. employing as fuel a gas already under pressure, thus not requiring vaporisation).

17. Internal combustion endothermic engine according to one of the preceding claims, characterised in that, for ignition within the same combustion chamber, a glow plug with or without preheating, an ignition by auxiliary injector with or without prechamber, an ignition with a downward injector to trigger a post-combustion (rapid instantaneous increase of power), an ignition with electricity feeding from an outer generator (by brush collector on a shaft or inside, by conductors integral with the rotation shaft and thus with the impeller), is provided.

18. Internal combustion endothermic engine according to one of the preceding claims, characterised in that it is provided a by-pass of a part of the heated air, directly on the exhaust collector (ejector) or of a cold autonomous air flow rate fed from another dynamic feeding opening.

19. Internal combustion endothermic engine according to one of the preceding claims, characterised in that said engine provides the flow of intake and exhaust air in the same direction, or according to a direction radially or axially different with respect to the rotation direction according to the constructive features chosen for convenience and/or in function of the engine application.

20. Internal combustion endothermic engine according to one of the preceding claims, characterised in that the engine according to the invention is started by an auxiliary start engine, or by compressed air, e.g. by and electro blower.

21. Internal combustion endothermic engine according to one of the preceding claims, characterised in that said endothermic engine have a pressure proof heater (s) (function and constant volume with intake and delivery valves) or holed for the dilution with cold air directly during the combustion.

22. Internal combustion endothermic engine according to each one of the preceding claims, substantially as illustrated and described.