What is the Difference Between Gas Turbine and Steam Turbine?

The main difference between gas turbines and steam turbines lies in the working fluid and the energy conversion process they use. Here are the key differences between the two:

• Working Fluid: In steam turbines, the working fluid is high-pressure steam, while gas turbines use hot and compressed gas or a mixture of gases as the working fluid.
• Energy Conversion Process: Steam turbines execute a water-based cycle called the Rankine cycle, where heat from combustion converts water into steam, which then rotates the turbine blades. Gas turbines, on the other hand, use the heat energy of gas or mixture of gases to produce rotation, executing the Brayton cycle or Joule cycle.
• Temperature: The internal temperature of steam turbines reaches only 500 to 650 degrees Celsius, while gas turbines can reach temperatures as high as 1,500 degrees Celsius during the combustion reaction.
• Combustion Process: Steam turbines don't have an air compressor or combustion system, but rather a boiler to heat water and generate steam. Gas turbines have an air compressor and a combustion system, which produces exhaust gases during the process.
• Applications: Steam turbines are used in thermal power plants and nuclear power plants, while gas turbines are widely used in gas turbine power stations and aircraft engines.
• Efficiency: Steam turbines generally have a higher efficiency than gas turbines.
• Maintenance: Steam turbines typically require more maintenance compared to gas turbines, which have lower maintenance costs.
• Flexibility: Gas turbines offer greater flexibility in terms of performance and response time, while steam turbines take longer to start and require more time to reach optimal efficiency.

Comparative Table: Gas Turbine vs Steam Turbine

The main difference between gas turbines and steam turbines is the working fluid used to generate power. Here is a comparison table highlighting the key differences between these two types of turbines:

Gas turbines use hot and compressed gases as the working fluid, while steam turbines use high-pressure steam as the working fluid. Gas turbines are more compact and have a higher power-to-weight ratio, making them suitable for applications like aircraft propulsion, power generation, and industrial processes. On the other hand, steam turbines are less prone to internal freezing and can utilize renewable thermal energy for heating, but they have a lower efficiency due to heat losses.