FR3044350A1 - DEVICE FOR OPERATING THE KINETIC ENERGY OF A GASEOUS FLOW - Google Patents

Abstract

The invention relates to a device (10) for exploiting the kinetic energy of a gas flow (F1), said device (10) comprising an energy conversion means (21), a first network (R1) configured for supplying said conversion means (21) with said gas stream (F1), and a second network (R2) configured to recover the gas stream (F2) downstream of said conversion means (21), characterized in that said first network (R1) is configured to be fed by an incident flux (F4) and a recirculated flow (F3) from said second network (R2), said incident flux (F4) having a pressure greater than that of said recirculated flow (F3) .

Description

The invention relates to a device for exploiting the kinetic energy of a gaseous flow.

The known energy conversion means, such as steam turbines which transform the expansion of a gas flow into mechanical energy, are all the more expensive as the gas stream arrives at their entry at high pressure and low flow. It is indeed more economical to provide such energy conversion means in collaboration with a gas stream having a low pressure and a high flow rate.

One of the objectives of the invention is to propose the transformation of a high-pressure, low-flow gas stream into a low-pressure, high-flow gas stream for injection into a kinetic energy conversion means which is of simple design.

Thus, the invention relates to a device for exploiting the kinetic energy of a gas flow, said device comprising an energy conversion means, a first network configured to feed said conversion means with said gas flow, and a second network configured to recover the gas stream downstream of said conversion means.

According to the invention, said first network is configured to be powered by an incident flow and by a recirculated flow from said second network, said incident flow having a pressure greater than that of said recirculated flow.

The recirculated stream recovered downstream of the conversion means is at low pressure, following the expansion provided by the conversion means. As it is taken from a flow which is itself the addition of the incident flow and a flow already recirculated, it advantageously has a high flow rate, in any case a flow advantageously higher than that of the incident flow. The incident flow has a high pressure which may cause the recirculated flow. The mixing of said recirculated stream and said incident stream thus makes it possible to form a gas stream with high flow and low pressure, which is particularly advantageous when used with a kinetic energy conversion means of simple design.

According to various embodiments of the invention, which may be taken together or separately: the device of the invention comprises a pipe connecting an outlet to an inlet of said gas stream of said conversion means, the device of the invention comprises furthermore an acceleration means, said acceleration means being configured to drive said recirculated flow by means of said incident flux, said acceleration means is positioned in said channel, said acceleration means is able to create a suction effect of said recirculated flow within said pipe, under the effect of the introduction of said incident flow in said pipe, - said acceleration means is a high-pressure gas injection means, - said means apparatus comprises straight injection nozzles, - said accelerating means comprises inclined injection nozzles, - the device of the invention furthermore, flow rectification means configured to rectify said gas stream, said rectifying means is positioned in said first network, in particular downstream of said acceleration means, said apparatus further comprises a fan configured to drive said recirculated flow, - said fan is positioned in said pipe, in particular upstream of said acceleration means, - said conversion means is a turbine. The invention will be better understood, and other objects, details, features and advantages thereof will become more clearly apparent in the following detailed explanatory description of at least one embodiment of the invention given to As a purely illustrative and nonlimiting example, with reference to the following appended schematic drawings: FIG. 1 schematically illustrates a first exemplary embodiment of a device for exploiting the kinetic energy of a gaseous flow according to FIG. FIG. 2 illustrates, schematically, a second exemplary embodiment of a device according to the invention, FIG. 3 illustrates, schematically, an example of a turbine volute intended for a device according to the invention.

As illustrated in FIGS. 1 and 2, the invention relates to a device for exploiting the kinetic energy of a gaseous flow. This gas flow is marked F1 in said figures. This gaseous stream F1 may be water vapor, or any fluid in the gaseous state, for example natural gas.

Said device 10 comprises an energy conversion means 21. The term "energy conversion means 21" means a consumer of gas flow, or a means of transforming a gas flow into mechanical energy. Here, said conversion means 21 is a turbine 21, for example a single stage turbine. This turbine 21 may advantageously take all forms of turbines low pressure difference.

This turbine 21 belongs to a power generation means 20 which advantageously comprises an electric energy generator 22 coupled to said turbine 21. Said turbine 21 is in particular intended to be driven by the expansion of said working fluid at the gaseous state.

The device 10 of the invention comprises a first network R1 configured to supply said turbine 21 with said gas stream F1, and a second network R2 configured to recover the gas stream F2 downstream of said turbine 21.

The term "network" means a set of pipes suitable for the circulation of a gas stream. Said gas flow F2, after expansion in the turbine 21, is a low pressure fluid which circulates at low speed in the second network R2.

According to the invention, the first network R1 is configured to be powered by an incident flow F4 and by a recirculated flow F3 from said second network R2, said incident flow F4 having a pressure greater than that of said recirculated flow F3.

"Incident flow" is understood to mean a flow F4 of high-pressure, low-flow gas injected into said first network R1 by nozzles 31. Said incident flow F4 leaves said nozzles 31 at very high speed.

In other words, said incident flux F4 disturbs the recirculated flow F3, in particular so as to accelerate said recirculated flow F3.

The term "recirculated flow" is understood to mean a gaseous flow F3 circulating within a pipe R3 connecting an outlet S to an inlet E of said gaseous flow of said turbine 21. In other words, the recirculated flow F3 is a flow derived from the gaseous flow. F2 downstream of said turbine 21. In other words, said recirculated flow F3 comes from the gas stream F2 downstream of said turbine 21; it circulates therefore, in the pipe R3, at low pressure and low speed.

The nozzles 31 mentioned above belong to an acceleration means 30. This acceleration means 30 is positioned in said duct R3, in particular so as to create a suction effect of said recirculated flow F3 within said duct R3. This suction effect makes it possible to ensure the diversion of a large amount of the gas stream F2 downstream of said turbine 21. This has the advantage of ensuring a high flow rate for the recirculated flow F3 in said pipe R3.

This suction effect is shown diagrammatically, in FIGS. 1 and 2, by the arrow denoting a flow F3 'upstream of an said acceleration means 30.

In other words, the suction created by the nozzles 3-1 attracts the gas flow, or recirculated flow F3, in the pipe R3 so as to derive a significant amount.

The pipe R3 becomes said "first network R1" downstream of said acceleration means 30. Said first network R1 is advantageously a gas flow mixing zone, in particular between the recirculated flow F3 and the incident flow F4; this is how the gas flow F1 is generated for the admission of said turbine 21.

The mixing of said recirculated flow F3 and said incident flow F4 makes it possible to form a gaseous stream F1 at high flow and low pressure, which is particularly advantageous when used with a turbine 21 of simple design, for example the mono-action turbine. -staged evoked above. On the other hand, the gaseous stream F1 arrives, advantageously, at the inlet of said turbine 21, with a high speed due to its entrainment by a flow F4 injected at high pressure.

In other words, the device 10 of the invention makes it possible to transform a high-pressure incident flow F4 into a high-flow gas stream F1. In other words, the incident flux F4 is a small flow rate that sets in motion a recirculated flow F3 of greater flow.

It should be noted that said injection nozzles 31 may advantageously be straight or inclined (details of nozzles not shown here) so as to optimize the entrainment of said gaseous flow F1. The entrainment of the gaseous flow F1 can be further optimized by means of flow rectification 40. FIG. 2 illustrates an example of positioning of such a flow rectifier 40 downstream of at least one acceleration means 30, at within the R3 pipeline.

The term "flow rectifier" means a set of blades (not detailed in the illustrations here), directed radially with respect to the main longitudinal extension direction of said first network R1; said blades may advantageously be substantially parallel to each other and to the main flow direction of said gaseous stream F1, or even substantially inclined with respect to said direction of flow of said gaseous flow F1.

Such a rectifying means 30 will advantageously be positioned within the first network R1, in particular downstream of at least one acceleration means 30.

In an embodiment not illustrated here, such a rectifying means 30 is positioned upstream of said acceleration means 30. This configuration is then particularly advantageous for twisting the recirculated flow F3 before the latter comes into contact with the flow. F4 incident.

In other words, the device 10 of the invention comprises a recirculation loop (the pipe R3), which itself carries a steam ejector (a said acceleration means 30), a steam straightener (a said rectifying means 40) and a steam diffuser (for example a baffle - not shown here).

As illustrated in FIG. 2, it is particularly advantageous to provide several acceleration stages 30, 30 'each coupled to a flow rectifying means 40, 40' so as to further optimize the entrainment of said gas flow F1. This makes it possible to accelerate sequentially the gaseous flow F1, in particular by several accelerating means 30, 30 'placed one after the other, within the same mixing zone, here, first network R1.

FIG. 3 illustrates a particular advantageous possibility of further optimizing the acceleration of a recirculated flow in order to bring it to the level of the intake of the turbine 21, that is to say at its volute 23, at a particularly high speed. In this exemplary embodiment, the volute 23 recovers several accelerated flows F1 coming from several "first network R1" mounted in parallel, each of them comprising an acceleration means 30, 30 ', 30 ", 30'", 30 " As described above.

It should be noted that the incident flux F4 or flows come from a high pressure loop, said high pressure loop being preferably distinct from said first and second networks R1, R2 mentioned above. On the other hand, the device of the invention may advantageously comprise at least one fan (not shown here) configured to drive said recirculated flow, said fan being positioned in said pipe R3, upstream of said acceleration means. Said fan is intended to pre-accelerate the recirculated flow F3, especially before mixing with the incident flow F4.

Said fan may advantageously be coupled to the axis of the turbine 21. In other words, the fan may be driven by the turbine 21.

It should be noted, for the sake of precision, that the gaseous flow F1 circulates in the vapor state, high temperature and high pressure through the first network R1, towards the turbine 21, through which it expands, while driving the turbine 21 in a rotational movement, movement advantageously transmitted to the generator 22 via a transmission shaft. Said generator 22 is advantageously an electromagnetic generator. It comprises a stator and a rotor, in particular electromagnetic.

It should also be noted that the working fluid leaves said turbine 21 and circulates in the state of vapor, high temperature and low pressure in the form of the flow referenced F2 in FIG. 1. Said flow F2 may advantageously be led to a component operating at relatively low pressure, for example a condenser whose function is to completely condense said fluid.

It should also be noted that the device 10 described above will find a particular application for unused gas flow detents, such as natural gas expansion or industrial boiler steam.

The device of the invention has the advantage of allowing the use of gas flow detents at low flow and high pressure difference. Indeed, this type of flow is conventionally more difficult to operate because resulting in high rotational speeds.

It should also be noted that variant embodiments are of course possible. In particular, it is also conceivable, in an exemplary embodiment not illustrated here, that the embodiments of FIGS. 2 and 3 are combined in such a way as to add up their advantages, or even to obtain new ones.

Claims (10)

claims Apparatus (10) for exploiting the kinetic energy of a gas flow (F1), said device (10) comprising an energy conversion means (21), a first network (R1) configured to supply said energy conversion means (21) with said gas stream (F1), and a second network (R2) configured to recover the gas stream (F2) downstream of said conversion means (21), characterized in that said first network (R1 ) is configured to be fed by an incident flux (F4) and a recirculated flow (F3) from said second network (R2), said incident flux (F4) having a pressure greater than that of said recirculated flow (F3). 2. Device (10) according to the preceding claim, comprising a pipe (R3) connecting an outlet (S) to an inlet (E) of said gas stream (F1) of said conversion means (F1). 3. Device (10) according to the preceding claim, further comprising an acceleration means (30), said acceleration means (30) being configured to drive said recirculated flow (F3) using said incident flow (F4 ). 4. Device (10) according to the preceding claim, wherein said acceleration means (30) is adapted to create a suction effect of said recirculated flow (F3) within said pipe (R3), under the effect of introducing said incident flow (F4) into said pipeline (R3). 5. Device (10) according to the preceding claim, wherein said acceleration means (30) is a high pressure gas injection means. 6. Device (10) according to the preceding claim, wherein said acceleration means (30) comprises injection nozzles (31) straight. The apparatus (10) of claim 5, wherein said accelerating means (30) comprises inclined injection nozzles (31). 8. Device (10) according to any one of claims 2 to 7, further comprising a flow rectifying means (40) configured to rectify said gas flow (F1). 9. Device (10) according to any one of claims 2 to 8, further comprising a fan configured to drive said recirculated flow (F3). Apparatus (10) according to any one of the preceding claims, wherein said conversion means (21) is a turbine.