US2413225A

US2413225A - Internal-combustion turbine

Info

Publication number: US2413225A
Application number: US505392A
Authority: US
Inventors: Griffith Alan Arnold
Original assignee: Rolls Royce PLC
Current assignee: Rolls Royce PLC
Priority date: 1941-05-14
Filing date: 1943-10-07
Publication date: 1946-12-24
Anticipated expiration: 1963-12-24
Also published as: GB585334A

Description

Dec. 24, 1946. GRlFFlTH 2,413,225

INTERNAL-COMBUSTION TURBINE Filed 001?. 7, 1943 3 Sheets-Sheet l 770i Mimic-m flTTofiA/EY NYE NTO.

1946' A. A. GRIFFITH INTERNAL-COMBUSTION TURBINE Filed Oct. 7, 1943 3 Sheets-Sheet 2 k/wzwToR 5% 1946' A. A. GRIFFITH 2,413,225

INTERNAL-CQMBUSTION TURBINE Filed Oct. 7, 1943 3 Sheets-Sheet 3 fi ORA/EY Patented Dec. 24, 1946 INTERNAL-COMBUSTION TURBINE Alan Arnold Grifiith, Derby, England, assignor to Rolls-Royce Limited, Derby, England, a British company Application October 7, 1943, Serial No. 505,392

In Great Britain May 14, 1941 This application corresponds to the application of Alan Arnold Griffith, Serial No. 6209/41, which was filed in Great Britain on May 14, 1941.

This invention relates to internal-combustion engines working on a cycle wherein heating takes place ata constant pressure and may, for example, be applied to turbine power-units of the kind described in the specification of my United States application Serial No. 505,389.

Since the air for combustion is compressed to the maximum working pressure in a turbine of the kind above set forth, its temperature is raised and for some purposes it is desirable to have available a supply of cool high-pressure air. Such air may be used, for example, in a construction of turbine as described in the specification of my United States application Serial No. 505,391, in which high-pressure air is used for balancin the end-thrust on the rotor elements.

This invention accordingly comprises an internal-combustion turbine wherein high-pressure air from the compressor extracted for auxiliary uses is cooled by the fuel which is passing to the burner.

According to another feature of this invention, it comprises in a turbine, the combination with a plurality of separately rotatable rotor-elements, of a central shaft carrying them which shaft is hollow and open at one end to the delivery end of the compressor, and is provided along its length with Openings to the spaces between the bearings and the rotor elements, and an air-cooler through which goiehiuel, on its way to the burner, is circulated to' cool the air entering the shaft.

According to another feature of this invention, the air-cooler aforesaid comprises a plurality of nested hollow cooling elements each of cylindrical form and so dimensioned radially to permit airflow axially between them. Alternatively, the aircooler aforesaid may be of substantially disc-like construction, and in either case is mounted adjacent the end of the rotor-shaft at the high-pressure end of the compressor to receive air therefrom.

In the accompanying drawings:

Figure 1 is a central sectional view showing the application of this invention to an internal-combustion turbine of the kind described in the specification of my application Serial No. 505,391,

Figure 21s a part sectional view on the line 2-2 of Figure 1,

Figure 3 is a part sectional view on the line 33 of Figure 1, and

Figure 4 is a central sectional view of a modified construction of air cooler.

6 Claims. (Cl. .60-41) Referring first to Figures 1 to 3, aninternalcombustion turbine power-unit comprises a central stationary shaft ill on which there are mounted a number of separate rotor-elements ll each carrying air-compressor blades I2 and turbine blades I3. Each of these rotor elements H is mounted by its own bearings M on the shaft In so as to be rotatable independently of the other elements, and the various elements are separated by thrust-bearings I5. The compressor-blades I2 deliver the high-pressure air past stationary guide-vanes Hi to an annular chamber H from which it passes to any suitable form of oil-fuelburner indicated generally by the reference It, being guided thereto by the stationary vanes 20. The products of combustion from the burner pass into the space 2| and thence through stationary guide-vanes 22 to the turbine-blades l3, to drive the unit.

The shaft l0 carrying the rotor-elements is hollow as indicated at 23 and a fuel supply pipe 24 is centrally situated in this shaft, extending from its rear end to the forward open end 25 of the shaft. This shaft I0 is furthermore provided with radial openings 26 giving accessto the spaces between the various rotor-elements.

The air-cooler forming the subject-matter of this invention is situated in a stationary housing 21, 28 of cylindrical form surrounding the open end 25 of the shaft 19 and in the construction illustrated in Figure 1, it comprises a number of hollow cylindrical shells 29 mounted coaxially and nested one within the other. These shells are so dimensioned radially as to provide axial air spaces between them. The air enters these spaces by openings 30 from the annular chamber l1 and circulates axially backwards and forwards as indicated by the arrows in the lower part of Figure 1 between the various shells 29 and then passes by the openings 3! to the space at the end of the shaft It! so that it can then enter the open end 25 thereof and pass out by the openings 26 aforesaid.

The oil supply which is effected through the pipe 24 above described is led therefrom by openings 32 to the interior of the innermost shell 29 and circulates therefrom through all the other shells in series, finally passing from the outermost one by the passage 33 to the burner. It will be seen that the air enters the cooler at its'outer periphery and sweeps over all the cooling elements, whilst the oil follows a similar but reverse path giving a counter-flow cooling whereby the air is effectively cooled and the oil is heated.

In order to provide adequate cooling surfaces,

the air-spaces between the elements 29 may be provided with corrugated metal strips 34 arranged endwise to the direction of flow of air to absorb heat from the air and transmit it by direct conduction to the shells 29.

In the' alternative construction illustrated in Figure 4, the air-cooler is constituted by a series of hollow disc-like elements 40; these elements are arranged co-axially with the shaft I and receive the oil from the fuel-supply pipe 24 by the openings 3| which communicate with the inner periphery of the first element 40. The oil thus passes radially outwards in the first element 40 and is transferred by the connections 4| at its outer periphery to the second element so that it travels radially inwards therein, and so on until it is finally delivered from the last element by the passage 42 to a burner indicated generally by the reference 43.

The air which is to be cooled enters the housing 44 of the cooler by the openings 45 from the highpressure end of the compressor and circulates radially inwards and outwards across all the cool ing elements 40, finally passing out by the opening 46 to the space surrounding the open end of the shaft l0, so that the cooled air can flow therethrough and out by the openings 26 to the rotor elements.

It will be seen that the heat-exchanger or aircooler in either of the forms above-described, is subjected to the high-pressure air on its outside, but this is balanced by the pressure of the fuelsupply on the inside, and since the fuel is supplied to the burner at a pressure substantially equal to that of the air, the pressures are balanced and it is possible to use a very light construction of cooling device and ensure a high efficiency of heat-transfer. These pressure conditions exist under all working conditions of the power-unit so that no special precautions in this respect are required. It is found that the cooling effect available with the fuel-oil for a turbodriven compressor is sufficient to cool the small quantity of air which is required for balancing the end-thrust on the rotor elements; a definite air-flow to assist in cooling the rotor-elements may be provided for, but in any case there is a certain amount of leakage-flow which is effective for the same purpose.

I claim:

1. In an internal-combustion turbine power plant, the combination of aturbine, an air compressor driven thereby, and supplying air thereto, means for supplying fuel to said turbine, means for extracting a portion of the air compressed by said compressor, means for causing said extracted air to be cooled by the fuel supplied to said turbine and means for conveying the cooled air to its place of utilization.

2. In an internal-combustion turbine power plant, the combination of a plurality of separately rotatable rotor elements, a central shaft supporting said elements, said shaft being hollow and open at one end, an air compressor whereof the delivery communicates with said hollow shaft to supply compressed air thereto, openings in said shaft providing communication from the interior thereof to the spaces between said rotor elements, means for supplying liquid fuel to said turbine. and an air cooler cooled by said liquid fuel and disposed between the outlet from the compressor and said hollow shaft.

3. In an internal-combustion engine power plant, the combination of a turbine, a compressor driven thereby and supplying air thereto, means for delivering air compressed by said compressor to the turbine elements and their bearings, an air cooler comprising a plurality of nested hollow cooling elements each of cylindrical form and so dimensioned radially as to permit air flow axially between them, means for supplying liquid fuel to said turbine through said air cooler, and means directing the cooling air for the turbine elements through said cooler.

4. In an internal-combustion turbine power plant, the combination of a turbine including rotor elements, an air compressor driven by said turbine, means for supplying fuel to said turbine, a plurality of co-axial cylindrical cooling elements, means for causing the liquid fuel to pass through some of said elements, means for delivering some of the air from said compressor between said cooling elements, and means for supplying said cool air to said rotor elements.

5. In an internal-combustion turbine power plant, the combination of a turbine including rotor elements, an air compressor driven thereby, an air cooler comprising a plurality of hollow disc-like elements, means for supplying liquid fuel through said elements, means for passing a portion of the air compressed by said compressor between said elements to cool it, and means for delivering the cool air to said rotor elements to cool them.

6. In an internal-combustion turbine power plant, the combination of a hollow shaft open at one end and provided with radial openings at intervals along its length, a plurality of rotor elements rotatably mounted on said shaft, with turbine blades on each of said elements, compressor blades on each of said elements for compressing air, a burner chamber, means for delivering compressed air to said chamber, means for delivering the products of combustion to said turbine blades, an air cooler, means for supplying liquid fuel therethrough to said burner chamber, means providing communication from the delivery chamber of said air compressor blades to said air cooler, and means for delivering air cooled in said air cooler to the interior of said hollow shaft and thence to the spaces between said rotor elements to cool them.

ALAN ARNOLD GRIEFTTI-I.