Description
The energy extracted from a gas expanding across the turbine can be converted into electric power by connecting the load side of the expander shaft to a generator. The Expander/Generator arrangement is typically available in following three configurations:
- Expander / Gearbox / Generator
- Expander / Generator
- Expander / High Speed Generator
Expander / Gearbox / Generator
In most cases, the operating speed of the expander will be at a higher RPM than the operating speed of the generator. It is therefore necessary to utilize a speed reduction gearbox to facilitate appropriate coupling speed.
In one such configuration, the high speed expander shaft is connected to a high speed coupling that transmits the torque to a speed reduction gearbox. The gearbox is then coupled to the generator. This configuration is typically used in medium to high power applications.
Expander / Generator
In most cases, the operating speed of the expander will be at a higher RPM than the operating speed of the generator. It is therefore necessary to utilize a speed reduction gearbox to facilitate appropriate coupling speed.
In another such configuration, the expander wheel is directly mounted on a shaft that also serves as the high-speed gearbox pinion eliminating the high-speed coupling. As with the Expander/Coupling/Gearbox/Generator, this configuration is also used in medium to high power applications.
Expander / High Speed Generator
In a third configuration, the expander wheel is directly mounted on a shaft that also serves as the high-speed generator’s shaft, eliminating the gearbox entirely. This configuration is limited to the power capacity of high-speed generators and is typically used in low to medium power applications.
The sizes 30-160 to 50-660 as indicated above can be combined with an alternator to form a turbo-expander / generator package.
