GB2326197A - Gas turbine engine with recuperator - Google Patents

Abstract

Air flows through an inlet 48, to a compressor 46, the outlet of which is connected to a counter-flow recuperator through which the air flows prior to entering a combustor 28 which exhausts to a turbine 34, which drives the compressor and exhausts via the recuperator. The arrangement of the engine components is stated to reduce eddies, vector changes, energy absorbing turns and pressure losses. The compressor may be of the axial or centrifugal type, and the combustor may be of the annular type or the type involving a plurality of can combustors.

Description

2326197 1 GAS TURBINE ENGINE This invention relates generally to a gas

turbine engine and more particularly a recuperated gas turbine engine arrangement having an improved fluid flow path.

The increasing demand for higher efficiency and configuration compactness is a driving force for gas turbine engine manufacturers. Many attempts have been made to improve the ef f iciency of gas turbine engines. one such.

attempt has included the addition of a recuperator to the existing gas turbine configuration.

An example of such an engine configuration can be found in U.S. Pat. No. 3,507,115 issued to L.R. Wisoka on April 21, 1970. The engine configuration disclosed in the Wisoka patent includes a generally conventional alignment including a central axis having an inlet end centered thereon, an axial compressor aligned about the central axis, a recuperator radially spaced from the central axis and a port interconnecting the compressor with the recuperator. Positioned radially inward of the recuperator and radially outward of the central axis is a combustion chamber, and positioned radially inward of the combustion chamber and centered upon the central axis is a turbine. The fluid flow in the Wisoka engine starts out in the inlet and flows axially from the front of the engine toward the rear of the engine and through the compressor, is turned radially outward away from the central axis by the port, is redirected axially through the recuperator toward the rear of the engine, is turned radially inward by a second duct toward the central axis and redirected axially back through the combustion chamber toward the front of the engine, is redirected radially inwardly toward the central axis by a duct and turned axially toward the rear of the engine into the turbine. The spent fluid flows from the turbine, is turned radially outward by a duct and is redirected axially through the recuperator toward the front of the engine and is redirected radially by a duct to the atmosphere.

2 Another example of such an engine configuration can be found in U.S. Pat. No. 3,831,374 issued to John Nicita on August 27, 1974. The engine configuration disclosed in Nicita includes a central axis, not shown, having an inlet end and a centrifugal compressor centered on the central axis. A recuperator is radially spaced f rom the central axis and a port interconnecting the compressor with the recuperator. Positioned radially inward of the recuperator and on line with the central axis is a combustion chamber.

Positioned on line with the central axis is a turbine interposed between the combustion chamber and the compressor. The f luid f low in the Nicita engine starts out in the inlet and f lows axially toward the rear of the engine, through the radial compressor resulting in a radially outward flow from the central axis, is turned axially toward the rear of the engine and is turned within the recuperator in a generally 'IS" configuration including radially inward toward the central axis, radially outward from the central axis and radially inward toward the central axis. From the recuperator, the flow is redirected axially toward the rear of theengine. The flow eventually is redirected (either by a wall or a fuel spray) axially towards the front of the engine through the combustion chamber and axially into the turbine. The spent fluid flows from the turbine, is turned radially outward by a duct and is redirected axially through the recuperator toward the rear of the engine and exits to the atmosphere.

Present gas turbine engines fail to effectively and efficiently position and locate the precise components making up the engine to more effectively improve engine efficiency by reducing associated pressure losses. As such present configurations result in a fluid flow which, in many applications, is very complex and result in many unnecessary counter directions of the flows forming unnecessary eddies, vector changes and energy absorbing turns resulting in increased pressure losses.

I,- 3 Additionally, the position and location of critical components influences servicing time and costs. For example, in many existing gas turbine engines the primary components requiring service, such as the combustor, first stage nozzle and turbine, are positioned in undesirable locations. This results in extensive disassembly during field servicing and replacement of parts.

Thus, the configuration of the engine, location and position of its components affects engine efficiency.

Furthermore, the fluid flow through the engine configuration and related components effects engine. efficiency.

In one aspect of the invention, a gas turbine engine defines a central axis, a front and a rear and is further comprised of the following components. A compressor section is positioned along the central axis near the rear of the gas turbine engine and is centered about the central axis. The compressor section has an inlet end being axially positioned toward the front of the gas turbine engine and an outlet end is axially positioned toward the rear of the gas turbine engine. A turbine section is positioned axially along the central axis intermediate the compressor section and the front of the gas turbine engine and is centered about the central axis. The turbine section operatively drives the compressor section and has an inlet end axially positioned toward the front of the gas turbine engine and an outlet end is axially positioned toward the rear of the gas turbine engine. A combustion chamber is positioned axially along the central axis intermediate the turbine section and the front of the gas turbine engine and has an inlet end positioned toward the front-of the gas turbine engine and an outlet end positioned toward the rear of the gas turbine engine. The inlet end is operatively connected to the outlet end of the compressor section and the outlet end is operatively connected to the inlet end of the turbine section. A primary surface recuperator is operatively interposed the outlet end of the 4 compressor section and the inlet end of the combustion chamber.

In another aspect of the invention, a gas turbine engine def ines a central axis, a f ront and a rear. The gas turbine engine is further comprised of the following components. A compressor section is axially positioned along the central axis near the rear of the gas turbine engine and is centered about the central axis. The compressor section has an inlet end and an outlet end having a recipient fluid exiting therefrom. A turbine section is positioned axially along the central axis intermediate the compressor section and the front of the gas turbine engine and is centered about the central axis. The turbine section operatively drives the compressor section and has an inlet end and an outlet end axially spaced one from the other. The outlet end has a donor fluid exiting therefrom. A combustion chamber is positioned axially along the central axis intermediate the turbine section and the front of the gas turbine engine and has an inlet end and an outlet end axially spaced one from the other. The inlet end is operatively connected to the outlet end of the compressor section and the outlet end is operatively connected to the inlet end of the turbine section. A primary surface recuperator - has a generally rectangular configuration and defines an inner portion spaced a radial distance from the central axis and an outer portion spaced from the central axis a radial distance being greater than the radial distance of the spacing of the inner portion. The recuperator further defines a recipient fluid inlet being in fluid communication with a recipient fluid outlet, a donor fluid inlet being in fluid communication with a donor fluid outlet, a plurality of heat recipient passages being interposed the recipient fluid inlet and outlet and a plurality of heat donor passages being interposed the donor fluid inlet and outlet. The recipient f luid inlet is operatively connected with the outlet end of the compressor section. The donor f luid inlet is operatively connected with the outlet end of the turbine section. The recipient fluid outlet is operatively connected with the inlet end of the combustion chamber, and the donor f luid outlet exits to an atmosphere. And, a f luid f low includes the recipient f luid being directed f rom the outlet end of the compressor section radially outward from the central axis to the recipient fluid inlet of the primary surf ace recuperator, being directed axially with respect to the central axis within the outer portion of the recuperator, being directed radially inward toward the central axis through the plurality of heat recipient passages, being directed to the inlet end of the combustion chamber through the combustion chamber and exiting axially along the central axis through the outlet end, being directed axially along the central axis to the inlet end of the turbine section and generally axially along the central axis through the turbine section and exiting the outlet end as the donor fluid, the donor fluid being directed radially outward from the central axis to the donor fluid inlet of the primary surface recuperator, being directed radially outward from the central axis through the plurality of heat donor passages and exits the donor fluid outlet.

In another aspect of the invention, a gas turbine engine comprising a central axis; a compressor section defining a recipient fluid flow exiting therefrom; a turbine section being drivingly connected to the compressor section and having a donor fluid flow exiting therefrom travelling axially along the central axis; a primary surface recuperator defining a plurality of heat recipient passages being in heat conducting communication with the recipient fluid flow and a plurality of heat donor passages being in heat conducting communication with the donor fluid flow; a combusti6h chamber being in communication with the recipient fluid flow and forming therein the donor fluid flow passing axially along the central axis prior to passing to said turbine section; and 1 6 fluid flow path having with reference to the central axis first axial flow through the compressor section, a first radially outward f low being communicated to the primary surface recuperator, a counter axial flow within the primary surface recuperator, a radially inward flow through the plurality of recipient passages, a second axial f low through the combustor chamber and the turbine section and a second radially outward flow through the plurality of donor passages.

In the accompanying drawings:

FIG. 1 is a side elevational view of a gas turbine engine embodying the present invention; FIG. 2 is a front elevational view of the gas turbine engine embodying the present invention; and FIG. 3 is an alternative side elevational view of a portion of a gas turbine engine embodying the present invention.

Referring to FIGS. I and 2, a gas turbine engine 10 is shown. The gas turbine engine 10 defines a central axis 12, a front 14 and a rear 16. Symmetrical positioned about the central axis 12 at the front 14 of the engine 10 is a first housing 18 having a plurality of fuel injectors 20 radially positioned about the central axis 12. The plurality of fuel injectors 20 each having a combustible fuel, not shown, supplied thereto in a conventional manner. A passage 24 is positioned within the first housing 18. Positioned inwardly of the first housing 18 toward the rear 16 of the engine 10 with respect to the first housing 18 is a combustion chamber 28. In this application, the combustion chamber 28 is of an annular design, is radially spaced about the central axis 12 and includes an inlet end 30 axially positioned along the central axis 12 toward the front 14 of the engine 10 and communicating with the plurality of injectors 20. An outlet end 32 of the combustion chamber 28 is axially positioned along the 7 central axis 12 toward the rear 16 of the engine 10 with respect to the inlet end 30 of the combustion chamber 28. As an alternative, the combustion chamber 28 could utilize a single can combustor or a plurality of can combustors axially positioned along the central axis 12 without changing the essence of the invention. operatively positioned about the central axis 12 and inwardly of the outlet end 32 of the combustion chamber 28 toward the rear 16 of the engine 10 is a turbine section 34 being supported by a second housing 36 interconnected with the first housing 18. The second housing 36 includes an annular passage 38 therein. The turbine section 34 defines an inlet end 40 axially positioned toward the front 14 of the engine 10 and adjacent the outlet end 32 of the combustion chamber 28 and an outlet end 42 having a donor fluid 44 exiting therefrom is axially positioned along the central axis 12 toward the rear 16 of the engine 10 with respect to the inlet end 40 of the turbine section 34. In this application, the turbine section 34 includes a plurality of turbine discs 45, but as an alternative a single disc or a radial turbine could be used without changing the essence of the invention. operatively driving and being connected to the turbine section 34 and centered about the central axis 12 near the rear 16 of the engine 10 is a compressor section 46, which, in this application, is an axial compressor, but as an alternative could be a centrifugal compressor. The compressor section 46 includes an inlet end 48 being axially positioned toward the front 14 of the engine 10 and an outlet end 50 having a recipient fluid 52 exiting therefrom is axially positioned toward the rear 16 of the engine 10.

A recuperator 60 has a generally rectangular configuration, is radially spaced from the central axis 12 and defines a front end 62 positioned near the front 14 of the engine 10. A rear end 64 is positioned near the rear 16 of the engine 10, an inner portion 66 is spaced a radial distance from the central axis 12 and an outer portion 68 8 is spaced from the central axis 12, a radial distance being greater than the radial distance of the spacing of the inner portion 66. A recipient fluid inlet 70 is located in the rear end 64 of the recuperator 60, and a donor fluid inlet 72 is located in the inner portion 66 intermediate the front end 62 and the rear end 64 of the recuperator 60. A recipient fluid outlet 74 is located in the inner portion 66 of the recuperator 60 intermediate the front end 62 and the donor fluid inlet 72 and a donor fluid outlet 76 is positioned in the outer portion 68 of the recuperator 60 intermediate the front end 62 and the rear end 64. The recuperator 60 further including a plurality of heat recipient passages 77 interposed the recipient fluid inlet 70 and the recipient fluid outlet 74 and a plurality of heat donor passages 78 interposed the donor fluid inlet 62 and the donor fluid outlet 66. Each of the plurality of heat recipient passages 77 and the plurality of heat donor passages 78 are positioned to have an axis 79 being generally radial or biased to the central axis 12. In this application, the recuperator 60 is of a primary surface type. And, the flow of recipient fluid 52 through the heat recipient passages 77 with respect to the flow of donor fluid 44 through the heat donor passages 78 has a counter flow action.

The outlet end 50 of the compressor section 46 communicates with an annular plenum 80 and is attached to the recipient fluid inlet 70 by a first expandable ducting system 82. The recipient fluid outlet 74 of the recuperator 60 communicates with the inlet end 30 of the combustion chamber 28 by way of a second expandable ducting system 84 and the passage 24 positioned within the first housing 18. The donor fluid inlet 72 of the recuperator 60 communicates with the outlet end 42 of the turbine section 34 by way of a third expandable duct system 90 and the annular passage 38 positioned within the second housing 36.

An output shaft 92 is in operative attachment with the turbine section 34 and extends from the rear 16 of the 9 engine 10. As an alternative, a secondary shaft 94 could be operatively connected to the turbine section 34 and extend from the front 14 of the engine 10.

The combination of engine 10 components and the configuration established defines the compact recuperated gas turbine engine 10 having a generally rectangular configuration of relatively minimum size in length, width and height. Furthermore, the position and location of the components define a fluid flow path 9 6 of each of the donor fluids 44 and the recipient fluid 52 through the engine 10 which is dynamically efficient and increases the overall engine efficiency. The gas turbine engine 10 defines the fluid flow path 96 being defined generally by an inverted twenty first letter of the Greek alphabet - Phi 11(p". For example, the fluid flow path 96, with reference to the central axis 12 and designated by the arrows, includes a first axial flow 98, a first radially outward flow 100, a counter axial flow 102, a radially inward flow 104, a second axial flow 106 and a second radially outward flow 108.

Industrial Applicability

In operation, as best shown in FIGS. I and 2, the recuperated gas turbine engine 10 includes a rather unique structure and defines a unique fluid flow path 96 having the generally inverted (p configuration. The recipient fluid 52 enters the inlet end 48 and travels axially along the axial compressor 46 toward the rear of the engine 10 being heated and compressed along the way. After being compressed, the recipient fluid 52 exits into the annular plenum 80 and is radially directed outwardly from the central axis 12 through the first expandable ducting system 82. The first expandable ducting system 82 directs the recipient fluid 52 axially through the recuperator 60 wherein the recipient fluid 52 in the plurality of heat recipient passages 77 absorbing additional heat from the donor fluid 44 adjacent thereto in the plurality of heat donor passages 78. Within the recuperator 60, the recipient fluid 52 is directed radially inwardly through the plurality of heat recipient passages 77 toward the central axis 12 to the second expandable ducting system 84 into the passage 22 within the first housing 18. From the passage 22 recipient fluid 52 is directed through the inlet end 30 of the combustion chamber 28 and flows axially therethrough. Fuel from the plurality of fuel injectors 20 is mixed with the recipient fluid 52 during the axial flow.

The combustible mixture formed therein is burned within the combustion chamber 28 forming the donor fluid 44 and exits axially along the central axis 12 from the outlet end 32 toward the rtiar 16 of the engine 10 into the inlet end 40 of the turbine section 34. The donor fluid 44 contacts the turbine discs 45 within the turbine section 34, travels axially along the central axis 12 therethrough toward the rear 16 of the engine 10 and drives the plurality of turbine discs 45 and the output shaft 92. The spent donor fluid 44 exits the outlet end 42 of the turbine section 34 is directed into the annular passage 38 and is directed radially outward away from the central axis 12 through the third expandable ducting system 90 into the donor fluid inlet 72 and flows radially outward through the plurality of heat donor passages 78 and exits the donor fluid outlet 76 being dissipated to the atmosphere. As the donor fluid 44 travels radially outward from the central axis 12 the recipient fluid 52 is travelling radially inward toward the central axis 12. Thus, as the donor fluid 44 nears the donor fluid outlet 76, the maximum heat has been drawn therefrom and the donor fluid 44 is at it coolest temperature. Conversely, with the reverse flow of the recipient fluid 52 through the recuperator 60, the recipient fluid 52 is also. at its coolest temperature, and heat transfer from the donor fluid 44 to the recipient fluid 52 still occurs.

The combination of the location and position of the components making up the gas turbine engine 10 increases 11 efficiency by effectively and efficiently positioning and locating the component which makes up the engine to more effectively improve the fluid flow path 96 of the engine. The present locations result in a f luid f low which is simple and results in the reduction of unnecessary counter directions of the f lows forming unnecessary eddies, vector changes, energy absorbing turns and pressure losses. For example, the hot donor fluid 44 formed within the annular combustor 28 travel in a straight line axially along the central axis 12, acts on the turbine discs 45 of the turbine section 34 while travelling in a straight line axially along the central axis 12, spends the majority of its heat energy and power to drive the turbine section 34 before being turned to enter the recuperator 60.

Thus, the engine 10 configuration, location and position of the components, has effectively increased engine efficiency. Furthermore, the fluid flow path, the inverted $g (P foil through the engine configuration and related components results in an improved, more efficient engine 10.

12 claims 1. A gas turbine engine defining a central axis and having a front and a rear; the engine comprising:

a compressor section being positioned axially along said central axis near the rear of said gas turbine engine and being centered about said central axis, said compressor section having an inlet end being axially positioned toward said front of said gas turbine engine and an outlet end being axially positioned toward said rear of said gas turbine engine; a turbine section being positioned axially along said central axis intermediate said compressor section and said front of said gas turbine engine and being centered about said central axis, said turbine section operatively driving said compressor section and having an inlet end being axially positioned toward said front of said gas turbine engine and an outlet end being axially positioned toward said rear of said gas turbine engine; a combustion chamber being positioned axially along said central axis intermediate said turbine section and said front of said gas turbine engine and having an inlet end being positioned toward said front of said gas turbine engine and an outlet end being positioned toward said rear of said gas turbine engine, said inlet end being operatively connected to said outlet end of said compressor section and said outlet end being operatively connected to said inlet end of said turbine section; and a primary surface recuperator being operatively interposed said outlet end of said compressor section and said inlet end of said combustion chamber.

2. A gas turbine engine according to claim 1, wherein said compressor section includes an axial compressor.

3. A gas turbine engine according to claim 1, wherein said compressor section includes a centrifugal compressor.

13 4. A gas turbine engine according to one of the preceding claims, wherein said turbine section includes a plurality of turbine discs.

5. A gas turbine engine according to any one of the preceding claims, wherein said combustion chamber includes an annular combustor.

6.

to A gas turbine engine according to any one of claims 1 wherein said combustion chamber includes a can J1 combustor.

7. A gas turbine engine according to claim 6, wherein said can combustor includes a plurality of can combustors.

is 8. A gas turbine engine according to any one of the preceding claims, wherein said primary surface recuperator includes a plurality of heat recipient passages having a recipient fluid flowing therethrough during operation and a plurality of heat donor passages having a donor fluid flowing therethrough during operation and said flow of recipient f luid and said f low of donor f luid are in a counter flow direction.

9. A gas turbine, substantially as described with respect to the accompanying drawings.