Combined Cycle Power Plants

The combined cycle power plant is power plant which consists of two power cycles.

i.Brayton Cycle

  1. Rankine Cycle

Brayton Cycle:

In Brayton cycle Gas turbine is powered by gas to spin the generator and produce electrical power. In this cycle Gas turbine also can be power by furnace oil or High speed diesel. The efficiency of brayton cycles gas turbines is up to 40%.

 

Rankine Cycle:

The other cycle is called HRSG (Heat recovery steam generation). In this process, steam is generated from the exhaust of gas turbine and this is fed to steam turbine to spin the attached generator. The temperature of exhaust is too high near 650c which is enough to generate useable steam. overall efficiency of power plant is increased from 40% to 54%. There are many other accessories for combined cycle power plant which work with parallel as like auxiliary pumps for fuel, water , lube oil, air intake etc.

Details of every cycle is covered in and other article.

Actuator

Actuator is a arm, coil, or something like this which converts one energy to mechanical energy for releasing or closing gas or liquid. in other words we can say it is a type of special motor.  The actuator can be electrical biased, mechanical biased, thermo biased, hydraulic biased or pneumatic biased.

Electrical Biased Actuator: electrical biased actuators are solenoids which are used to control flow, it can be fluid or pneumatic flow. solenoid also control electrical energy.

Mechanical Biased Actuator: Mechanical biased actuators are hydraulic or pneumatic cylinders which control the flow of fluid or compressed air.

Thermo Biased Actuator: Actuators which are actuated by thermally or magnetically are called thermo biased actuators.