1. Fuel Preparation: Natural gas is transported from production sites through pipelines to power plants. Before combustion, it may undergo some purification or treatment processes to remove impurities.
2. Gas Turbine: The main component of an NGCC plant is the gas turbine. Natural gas is mixed with air and compressed by the gas turbine's compressor. The compressed mixture is then directed into the combustor.
3. Combustion: Inside the combustor, the compressed air and natural gas mix is ignited. The heat generated by combustion expands the gases, causing them to flow rapidly through the turbine blades. As the high-pressure, high-temperature gases pass through the turbine blades, they cause the blades to rotate.
4. Power Generation: The rotating turbine blades are connected to the generator, which converts the mechanical energy from the turbine into electrical energy. The generator produces alternating current (AC) electricity.
5. Heat Recovery Steam Generator (HRSG): After passing through the gas turbine, the exhaust gases still contain significant heat. To extract this heat and generate additional electricity, an HRSG is used. The HRSG utilizes the heat from the exhaust gases to convert water into steam.
6. Steam Turbine: The high-pressure steam generated in the HRSG is directed to the steam turbine. As the steam flows through the steam turbine's blades, it expands and causes the blades to rotate. The rotation of the steam turbine generates additional mechanical energy.
7. Condenser: After passing through the steam turbine, the steam is condensed back into water in the condenser. The condenser uses cooling water from an external source, such as a river or cooling tower, to cool down the steam.
8. Electrical Grid: The electricity generated by the gas turbine and the steam turbine is combined and fed into the electrical grid for distribution to consumers.
NGCC plants are popular for electricity generation due to their high efficiency and relatively lower emissions compared to traditional coal-fired power plants. They can also be used in combined heat and power (CHP) systems, where the waste heat from electricity generation is used to provide heating or cooling for industrial or commercial purposes, further increasing their efficiency and minimizing energy waste.
