Anti-Windmill Brake
The Problem
- Even when shutdown, gas turbines continue to suffer serious damage.
- The slow rotational speed associated with windmilling is insufficient to generate the centrifugal force required to prevent blade chatter.
- Prolonged periods of windmilling can destroy turbine blading.
- Windmill damage can cost upwards of £250,000 to repair.
The Solution
Designed to complement the Posiflow retrofit programme, TCL has developed an Anti-Windmill Brake. It fits in place of the HP fuel pump and uses a solenoid operated disk brake to apply sufficient decelerating torque to stop the windmilling gas generator. Systems are included to prevent brake application whilst the engine is fired.
| Specification |
| Supply Voltage |
110 VDC / 24 VDC |
| Brake Solenoid Current |
0.3A @ 24 VDC |
| Air Gap |
0.012 + / - 0.003 |
| Brake Torque |
40 lb ft +/- 2 lb ft @ 50rpm +/- 5 rpm |
Phonic wheel mounted brake
TCL have developed an Anti-Windmill brake for the RR Avon that fits in place of the geared wheel used for speed measuring, or phonic wheel. Because the brake does not pick up the HP fuel pump drive the brake can be fitted in isolation and does not require a Posiflow fuel system modification. The brake has been installed on a number of RR Avon gas turbine installations and has proved very successful at preventing windmilling at low speeds.
The brake is manufactured with four-speed probe location holes and can be supplied with two or four magnetic pick-up type speed probes.
Video
Below you will find a video. This video allows you to hear the turbine blade clatter that occurs during windmilling while the gas turbine is shut down. This will be prevented if fitted with an Anti-Windmill Brake.