Gas turbines have grown in popularity over the years as the energy sources in most plants. The system is used to produce electrical energy to power engines and over the last two decades, gas turbines have been replacing coal-fired power plants. Some of the benefits of gas turbines include lower operational costs, efficiency and durability, eco-friendliness, higher operational speeds among others.
Importance of a Fire Protection System
However, there is also the risk of turbine fire and this is where a fire protection system comes in. A Turbine power plant is very expensive and if it is damaged by fire, you will have to contend with very costly repairs. In most cases, you might be forced to overhaul the entire plant and this can devastate your business. To appreciate why you need to invest in a power protection system, you need to know how it works. The low-pressure double-discharge CO2 extinguishing system protects the gas turbine against damage.
A fire protection system comprises smoke detectors, indoor sprinklers and extinguishers. The fire-fighting system should offer total saturation to guarantee there is no chance of the fire recurring. This is enabled by lemon scented carbon dioxide (CO2) discharge to create an inert atmosphere in and around the turbine to ensure the fire is completely extinguished thus preventing further damage.
The fire protection supply system consists:
- Carbon dioxide tank: This is the most important component and is assembled on a skid together with an instrument panel, two chiller units and junction boxes.
- Carbon dioxide panels which are inside the gas turbine together with load coupling enclosures.
- External piping
- Tank weighing nozzles
- Instrumentation system: Inside the gas turbine, there is an electrical and instrumentation system consisting a heat detector. This is the system that will initiate the action of the fire protection system. It gives a signal if fire is detected in any of the protected compartments.
The internal system features two distinct CO2 discharge systems, which work concurrently to guarantee the gas turbine is safe. These two systems are:
- Initial discharge: This smothers the fire by drastically reducing the amount of oxygen inside the gas turbine compartment. It also closes the ventilation damper.
- Slow/maintenance CO2 discharge: Maintains an extinguisher concentration of 30% in the gas turbine enclosure to avoid relighting. Relighting can occur due to the high temperatures of metallic components.
The role of the pressure switches in the fire protection system is to detect levels of pressure in the discharge lines. Any fall in pressure triggers a fire signal.