Comment une centrale thermique à cycle combiné transforme le gaz en électricité - EDF

Summary

The video explains how a combined cycle gas power plant generates electricity by utilizing both gas and steam turbines. It describes the process starting from the compression of air, mixing it with natural gas for combustion, and using the resulting exhaust gases to spin a turbine connected to an alternator. The system also captures waste heat to produce steam, which drives a second turbine, further enhancing efficiency. The energy generated is transformed to high voltages for transmission. This method reduces CO2 emissions compared to coal plants and can quickly adapt to fluctuating energy demands.

Takeaways

• 😀 A combined cycle gas power plant uses natural gas combustion to generate electricity.
• 🌬️ The system consists of a gas turbine and a steam turbine, both linked to generators.
• 🔥 Air is compressed and mixed with fuel in a combustion chamber, igniting to produce exhaust gases.
• ⚡ The gas turbine drives the generator, creating electricity from the combustion process.
• 💧 Exhaust heat is recovered to heat water, producing steam for the steam turbine.
• 🚂 The steam turbine generates additional electricity, enhancing overall output.
• 🔌 The combined electrical output is transformed to high voltages for efficient transport.
• 💨 Emissions are filtered, significantly reducing CO2 output compared to coal plants.
• ⚙️ Combined cycle plants are flexible and can quickly ramp up to full capacity.
• 🌡️ These plants are ideal for meeting peak demand, especially during cold weather.

Q & A

What is a combined cycle thermal power plant?

A combined cycle thermal power plant generates electricity using the heat from burning natural gas, combining both gas and steam turbines for increased efficiency.

How does the gas turbine in a combined cycle plant work?

In the gas turbine, air is compressed in a high-pressure compressor, mixed with fuel in a combustion chamber, ignited, and the resulting hot gases drive the turbine to produce electricity.

What happens to the exhaust gases from the gas turbine?

The exhaust gases from the gas turbine are captured and used to heat water in a boiler, turning it into steam for the steam turbine.

What role does the steam turbine play in a combined cycle plant?

The steam turbine uses steam produced from heated water to generate additional electricity, enhancing the overall energy output of the plant.

How is electricity generated in the alternator?

Electricity is generated in the alternator through the interaction between the rotor's electromagnets and the stationary coils of copper wire in the stator.

Why is the voltage of the electricity increased before transmission?

The voltage is increased to 225,000 or 400,000 V to facilitate easier and more efficient transport of electricity over long distances via high-voltage transmission lines.

What happens to the steam after it exits the steam turbine?

After exiting the steam turbine, the steam passes through a condenser where it is cooled and transformed back into water, which is then returned to the boiler.

What measures are taken to reduce emissions in combined cycle plants?

Combined cycle plants use natural gas as fuel, which significantly reduces CO2 emissions compared to coal-fired power plants.

What are the advantages of combined cycle plants over traditional thermal power plants?

Combined cycle plants have higher efficiency, can reach full power in less than an hour, and are more flexible in responding to fluctuations in electricity demand.

How do combined cycle plants respond to peak electricity demand?

These plants can quickly ramp up to full power to meet high electricity demand during peak periods, such as cold days when energy consumption increases.