GB2586888A

GB2586888A - Reduced weight gas turbine

Info

Publication number: GB2586888A
Application number: GB1914504.4A
Authority: GB
Inventors: Desmond Lewis Stephen
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-09-03
Filing date: 2019-10-08
Publication date: 2021-03-10
Also published as: GB201914195D0; GB201914504D0; GB201913389D0

Abstract

A gas turbine 1 has at least one turbine stage 2 which is connected via a gearbox 4 to increase the rotational velocity of at least one compressor stage 3 relative to the turbine stage. There may be two or more turbine stages and there may be two or more compressor stages. The gearbox may be in front of the compressor stage and the gearbox may be behind the compressor stage. The gas turbine may power a turboprop and/or a turbofan and/or a turbojet and/or an electrical generator.

Description

Reduced weight gas turbine This invention relates to a gas turbine with an increased power to weight ratio.

Gas turbines typically have several compressor stages before a combustion chamber to gradually increase the pressure before combustion. This then exhausts through turbine stages which provide the power. Multiple compressor stages were first used due to the fact that a single compressor couldn't spin fast enough safely to compress the flow, thus slower spinning multiple stages provide the compression required. However, with the advent of aero gas turbines improved materials enabled turbine stages to work under very harsh conditions which enabled a great deal of work to be done with fewer stages. However, this would mean that if the compressor stages were as robust as the turbine stages, or even slightly more robust, they would be greatly underused unless they were spinning much faster since they are in a much less harsh environment. To overcome this, the present invention proposes a gas turbine comprising at least one turbine stage mechanically connected to at least one compressor stage via a gearbox wherein said gearbox increases the rotational velocity of said compressor stage relative to rotational velocity of said turbine stage.

Due to the compressor stage spinning faster than the turbine stage a smaller compressor stage with fewer fan blades can be used since the compressor is now working harder. This also means that the turbine stage is still doing the same amount of work since it is turning a smaller compressor stage faster. This results in a lighter engine producing similar power to heavier engines since the compressor is now lighter which is particularly important for single stage to orbit vehicles such as spaceplanes.

Preferably, there are two or more turbine stages.

Preferably, there are two or more compressor stages.

Preferably, said gearbox is in front of said compressor stage. Preferably, said gearbox is behind said compressor stage.

Preferably, said gas turbine powers a turboprop and/or a turbofan and/or a turbojet and/or an electrical generator.

An example of the invention will now be described by referring to the accompanying drawing: - figure 1 shows a side view of the reduced weight gas turbine and; - figure 2 shows a side view of the reduced weight gas turbine and; - figure 3 shows a side view of the reduced weight gas turbine according to the invention. ^

This enables the cooler compressor stage to spin faster doing more work for its mechanical abilities similar to how the turbine stage is doing work to the limits of its mechanical abilities which enables fewer compressor stages or fewer compressor blade rows or fewer compressor blades per compressor wheel/disk.

This allows a lighter engine to be made as well as a cheaper one which is beneficial to aviation in general and particularly important for reducing weight on spaceplanes. The gas turbine could also be used for ground-based electricity generation.

This also reduces the amount of stators required which also potentially helps allow a more compact shorter shaft and engine as shown in figure 3.

There is also the potential for a turbine stage to turn at a reduced speed, reducing the centrifugal loading on the turbine blades to enable a higher turbine inlet temperature while maintaining compressor velocities and pressures.

Higher pressure ratios which create higher turbine inlet temperatures could also be achieved by having a more expanded and cooler turbine inlet flow turning an increased size reduced velocity first turbine stage with increased compressor velocities and pressures created by the gearbox as shown in figure 4. ^

Claims

Claims 1 A gas turbine comprising at least one turbine stage mechanically connected to at least one compressor stage via a gearbox wherein said gearbox increases the rotational velocity of said compressor stage relative to rotational velocity of said turbine stage.
2 A gas turbine according to claim 1, wherein there are two or more turbine stages.
3 A gas turbine according to any of the preceding claims, wherein there are two or more compressor stages.
4 A gas turbine according to any of the preceding claims, wherein said gearbox is in front of said compressor stage.
A gas turbine according to any of the preceding claims, wherein said gearbox is behind said compressor stage.
6 A gas turbine according to any of the preceding claims, wherein said gas turbine powers a turboprop and/or a turbofan and/or a turbojet and/or an electrical generator.